Huang, Zhi Qiang; Raska, Milan; Stewart, Tyler J; Reily, Colin; King, R Glenn; Crossman, David K; Crowley, Michael R; Hargett, Audra; Zhang, Zhixin; Suzuki, Hitoshi; Hall, Stacy; Wyatt, Robert J; Julian, Bruce A; Renfrow, Matthew B; Gharavi, Ali G; Novak, Jan
Autoantibodies against galactose-deficient IgA1 drive formation of pathogenic immune complexes in IgA nephropathy. IgG autoantibodies against galactose-deficient IgA1 in patients with IgA nephropathy have a specific amino-acid sequence, Y1CS3, in the complementarity-determining region 3 of the heavy chain variable region compared with a Y1CA3 sequence in similar isotype-matched IgG from healthy controls. We previously found that the S3 residue is critical for binding galactose-deficient IgA1. To determine whether this difference is due to a rare germline sequence, we amplified and sequenced the corresponding germline variable region genes from peripheral blood mononuclear cells of seven patients with IgA nephropathy and six healthy controls from whom we had cloned single-cell lines secreting monoclonal IgG specific for galactose-deficient IgA1. Sanger DNA sequencing revealed that complementarity-determining region 3 in the variable region of the germline genes encoded the Y1C(A/V)3 amino-acid sequence. Thus, the A/V>S substitution in the complementarity-determining region 3 of anti-galactose-deficient-IgA1 autoantibodies of the patients with IgA nephropathy is not a rare germline gene variant. Modeling analyses indicated that the S3 hydroxyl group spans the complementarity-determining region 3 loop stem, stabilizing the adjacent β-sheet and stem structure, important features for effective binding to galactose-deficient IgA1. Understanding processes leading to production of the autoantibodies may offer new approaches to treat IgA nephropathy. Copyright © 2016 by the American Society of Nephrology.
Pribylova, Jaroslava; Krausova, Klara; Kocourkova, Ingrid; Rossmann, Pavel; Klimesova, Klara; Kverka, Miloslav; Tlaskalova-Hogenova, Helena
Human colostrum and milk provide a newborn with immunomodulatory components, ensuring protection and proper development of the immune system. Secretory IgA antibodies in colostrum represent the first line of defence against harmful substances, but their potential spectra of reactivity with autoantigens remains unclear. Here, we characterised the repertoire of natural sectretory IgA autoantibodies in colostrum of healthy mothers. The human colostrum samples from 39 healthy mothers were analyzed for autoantibodies by indirect immunofluorescence, dot blots, immunoblots and ELISA. We found that there is high diversity in reactivities of colostral IgA antibodies to autoantigens among individual samples. Using tissue sections and biochips commonly used for autoimmunity testing, we found that most samples reacted with monkey ovary (79.3%), monkey pancreatic tissue (78.6%), human HEp-2 cells (69%) and monkey adrenal gland (69.0%), fewer samples reacted with monkey liver tissue (47.2%), rat stomach (42.9%), monkey testicular tissue (41.4%), monkey salivary gland (39.3%), rat kidney (32.1%) and monkey cerebellar tissue (17.9%). At the protein level, we detected reactivity of IgA with 21 out of 25 (auto) antigens. The majority of the samples reacted with the pyruvate dehydrogenase complex, E3 ubiquitin ligase, cytosolic liver antigen, promyelocytic leukemia protein and nuclear pore glycoprotein-210. Using ELISA, we found reactivity of colostral IgA antibodies against examined extractable nuclear antigens, double stranded DNA, phospholipids and neutrophil cytoplasm. The broad spectrum of polyreactive natural autoantibodies present in human colostrum may contribute to proper development of mucosal immune system of the breastfed infant.
Savolainen, Markku J.
Aims. This study investigated the association of autoantibodies binding to oxidized low-density lipoproteins (oxLDL) in diabetic retinopathy (DR). Methods. Plasma from 229 types 1 and 2 patients with DR including diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) was analysed with ELISA-based assay to determine IgA, IgG, and IgM autoantibody levels binding to oxLDL. The controls were 106 diabetic patients without retinopathy (NoDR) and 139 nondiabetic controls (C). Results. PDR group had significantly higher IgA autoantibody levels than DME or NoDR: mean 94.9 (SD 54.7) for PDR, 75.5 (41.8) for DME (p = 0.001), and 76.1 (48.2) for NoDR (p = 0.008). There were no differences in IgG, IgM, or IgA that would be specific for DR or for DME. Type 2 diabetic patients had higher levels of IgA autoantibodies than type 1 diabetic patients (86.0 and 65.5, resp., p = 0.004) and the highest levels in IgA were found in type 2 diabetic patients with PDR (119.1, p > 0.001). Conclusions. IgA autoantibodies were increased in PDR, especially in type 2 diabetes. The high levels of IgA in PDR, and especially in type 2 PDR patients, reflect the inflammatory process and enlighten the role of oxLDL and its autoantibodies in PDR. PMID:28090539
Xiong, Yin; Gao, Sihai; Luo, Guangwei; Cheng, Guilian; Huang, Wei; Jiang, Rui; Wang, Yueqin; Cui, Tianpen
Autoimmune processes are involved in the progression of chronic obstructive pulmonary disease (COPD). Autoantibodies against cytokeratin 18 (CK18) and cytokeratin 19 (CK19) could be associated with lung injury. We undertook this study to investigate the role of these autoantibodies against CK18 and CK19 in the development of COPD. We used blood samples from 228 COPD patients or 136 healthy controls and male C57BL/6j mice as experimental subjects to analyze the serum autoantibody levels against CK18 or CK19 autoantigen by enzyme-linked immunosorbent assay (ELISA). We found that the circulating autoantibody levels of IgG, IgA, IgM against CK18 and CK19 were elevated in patients with COPD compared with healthy controls, which were increased gradually as the severity of the disease increases, especially in GOLD III and GOLD IV with the exception of anti-CK19 IgG and anti-CK18 IgA autoantibodies. Moreover, we observed that the serum levels of anti-CK18 and anti-CK19 IgG autoantibodies were higher in mice exposed to cigarette smoke compared with mice exposed to room air for 6 months and 9 months. Additionally, we identified the distribution of antibodies and the presence of autoantibodies (IgG) against CK18 and CK19 in the damaged lung tissues of mice. Increased circulating autoantibodies against CK18 and CK19 are closely related to the progression of COPD, which play an important role in the process of lung injury in COPD, suggesting that it is promising for anti-CK18 and anti-CK19 autoantibodies to serve as a tool to monitor lung damage and guide treatment. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.
Shimoda, M; Inoue, Y; Ametani, A; Fujiwara, J; Tsuji, N M; Kurisaki, J; Azuma, N; Kanno, C
IgA antibodies in the mucosal immune system are produced specifically to environmental antigens such as virus and bacteria, and possibly to some food components, which will provide a potential luminal antigen, DNA. To study the immune response to DNA in the gut, we established B-cell hybridomas producing IgA monoclonal antibodies (mAb) from Peyer's patches (PP) of non-immunized, non-autoimmune, specific pathogen-free BALB/c mice, and examined their specificity by enzyme-linked immunosorbent assay (ELISA). Three mAb out of 18 bound strongly to self, bacterial and synthetic DNA, with Kd of about 10-7 m. One of the three mAb also reacted with the histone component and another reacted with some mouse food component. The VH genes of these three mAb have not previously been reported to have anti-DNA specificity, and carry putative somatically mutated sites favouring DNA binding in CDR. The features resemble those of anti-DNA antibodies found in human and murine models of systemic lupus erythmatosus (SLE), and are indicative of an antigen-driven selection process. Our findings suggest that even in normal healthy animals, anti-DNA antibodies of IgA isotype can be produced in certain peripheral environments such as in PP by spontaneous antigenic stimulation. PMID:9824476
Masuda, Jun-Ichi; Omagari, Katsuhisa; Ohba, Kazuo; Hazama, Hiroaki; Kadokawa, Yoshiko; Kinoshita, Hideki; Hayashida, Kenji; Hayashida, Kazuhiro; Ishibashi, Hiromi; Nakanuma, Yasuni; Kohno, Shigeru
Although anti-mitochondrial antibody (AMA) is the characteristic serological feature of primary biliary cirrhosis (PBC), its pathogenetic role remains unclear. We tested sera from 72 Japanese patients with histologically confirmed PBC for AMA by indirect immunofluorescence, anti-pyruvate dehydrogenase complex (PDC) by enzyme inhibition assay, immunoglobulin (Ig) G class anti-PDC by ELISA, and IgG, IgM, and IgA class anti-2-oxo-acid dehydrogenase complex (2-OADC) by immunoblotting. Of the 72 sera, 60 (83%), 50 (69%), 42 (58%), and 71 (99%) were positive for AMA by immunofluorescence, enzyme inhibition assay, ELISA, and immunoblotting, respectively. There was no significant correlation between histological stages and AMA by immunofluorescence, PDC inhibitory antibodies by enzyme inhibition assay, IgG class anti-PDC antibodies by ELISA, or IgG and IgM class anti-2-OADC by immunoblotting. IgA class anti-2-OADC by immunoblotting was more frequent in stages 2-4 than in stage 1 (P = 0.0083). Of the IgA class anti-2-OADC, anti-PDC-E2 (74 kDa) and anti-E3BP (52 kDa) were more frequent in stages 2-4 than in stage 1 (P = 0.0253 and 0.0042, respectively). Further examination of histopathological findings in 53 of 72 liver biopsy specimens showed that IgA class anti-PDC-E2 and IgA class anti-E3BP were associated with bile duct loss, and IgA class anti-PDC-E2 was also associated with interface hepatitis and atypical ductular proliferation. IgA is known to be secreted into the bile through biliary epithelial cells, implying that IgA class anti-PDC-E2 and E3BP may have a specific pathogenetic role during their transport into the bile by binding to their target antigen(s) in biliary epithelial cells, and this may be followed by dysfunction and finally destruction of biliary epithelial cells. Our present results suggest that these autoantibodies against 2-OADC detected by immunoblotting may be associated with the pathogenesis and pathologic progression of PBC.
Harff, G A; Backer, E T
Variant electrophoretic patterns of lactate dehydrogenase isoenzymes were studied. By radial immunodiffusion and immunoelectrophoresis, immunoglobulin and light chain class of autoantibodies to lactate dehydrogenase were identified in nine sera: seven of these sera demonstrated IgG (5 lambda, 2 kappa) autoantibodies to lactate dehydrogenase, the other two demonstrated IgA (both kappa) autoantibodies to lactate dehydrogenase, the other two demonstrated IgA (both kappa) autoantibodies to lactate dehydrogenase. We conclude that radial immunodiffusion and immunoelectrophoresis are equally effective for identifying auto-antibodies to lactate dehydrogenase in serum. Radial immunodiffusion, however, is easier to perform than immunoelectrophoresis.
Background Atopic dermatitis (AD) is a multifactorial chronic inflammatory skin disease presenting with a relapsing clinical pattern similar to chronic autoimmune disease. Several human transglutaminases have been defined and keratinocyte transglutaminase (TG1) and epidermal transglutaminase (TG3) expressed in the epidermis are associated with epidermal barrier dysfunction. Since impairments to the epidermal barrier represent an important factor in AD, we hypothesized that IgA autoantibodies specific for TG1 (IgA-anti-TG1) and TG3 (IgA-anti-TG3) may affect AD development during childhood. Methods Active AD patients (n = 304), 28 patients with biopsy-confirmed coeliac disease (CD), 5 patients with active AD and CD, and 55 control patients without CD and skin diseases were enrolled into the study. IgA-anti-TG1 and IgA-anti-TG3 reactivity was determined using an enzyme-linked immunosorbent assay. IgA-anti-TG2 were defined using a fluoroenzyme immunoassay. Results IgA-anti-TG1 antibodies were found in 2% and IgA-anti-TG3 antibodies in 3% of patients with active AD. Two out of the 5 patients with AD and concomitant CD had IgA-anti-TG1 and IgA-anti-TG2 antibodies. In CD patients, 36% of individuals presented with elevated IgA-anti-TG1 antibodies and 18% presented with elevated IgA-anti-TG3 antibodies and all CD patients presented with IgA-anti-TG2 antibodies (significantly different from AD patients and controls, p < 0.05). In CD patients, IgA-anti-TG1 and/or IgA-anti-TG3 seropositivity tended to appear concurrently, whereas only one patient with AD had both types of autoantibodies. Conclusions IgA-anti-TG1 and IgA-anti-TG3 seropositivity was rare in active AD but frequent in CD patients. The level of circulating antibodies related to skin lesions could be studied by determining the levels of IgA-anti-TG1 and IgA-anti-TG3 in skin biopsies of AD patients. PMID:24885370
Gonzalez-Gronow, Mario; Cuchacovich, Miguel; Francos, Rina; Cuchacovich, Stephanie; Blanco, Angel; Sandoval, Rodrigo; Gomez, Cristian Farias; Valenzuela, Javier A; Ray, Rupa; Pizzo, Salvatore V
Autoantibodies from autistic spectrum disorder (ASD) patients react with multiple proteins expressed in the brain. One such autoantibody targets myelin basic protein (MBP). ASD patients have autoantibodies to MBP of both the IgG and IgA classes in high titers, but no autoantibodies of the IgM class. IgA autoantibodies act as serine proteinases and degrade MBP in vitro. They also induce a decrease in long-term potentiation in the hippocampi of rats either perfused with or previously inoculated with this IgA. Because this class of autoantibody causes myelin sheath destruction in multiple sclerosis (MS), we hypothesized a similar pathological role for them in ASD. Copyright © 2015 Elsevier B.V. All rights reserved.
Omagari, Katsuhisa; Kadokawa, Yoshiko; Nakamura, Minoru; Akazawa, Shiho; Ohba, Kazuo; Ohnita, Ken; Mizuta, Yohei; Daikoku, Manabu; Yatsuhashi, Hiroshi; Ishibashi, Hiromi; Kohno, Shigeru
Although antimitochondrial antibody (AMA) is the characteristic serological feature of primary biliary cirrhosis (PBC), its pathogenic role remains unclear. In our previous study, we reported a positive correlation between immunoglobulin (Ig) A class anti-2-oxo-acid dehydrogenase complex (2-OADC) and histopathological stage. To determine whether the appearance of IgA class anti-2-OADC by immunoblotting represents an early marker of more aggressive disease or whether it is late finding during the disease course of PBC, we tested not only the entire IgA class but also IgA1, IgA2 and secretory IgA class anti-2-OADC in serial serum samples from 15 patients with PBC. During the median observation period of 51 months, four cases showed histopathological progression (from stage 1 to 2, stage 1 to 3, stage 1 to 4 and stage 2 to 4). There was no statistically significant correlation between the above IgA class anti-2-OADCs and histopathological progression. There was no significant correlation between histopathological stages and IgA2 class anti-2-OADC or secretory IgA class anti-2-OADC by immunoblotting. IgA class anti-2-OADC was more frequent in stages 3-4 than in stages 1-2 (p = 0.0049), but IgA1 class anti-2-OADC was more frequent in stages 1-2 than in stages 3-4 (p = 0.0232). Our present study demonstrated that serum IgA class 2-OADC was not a predictive marker of histopathological progression but was associated with the histopathological stage of PBC. Although the IgA class AMA may have a specific pathogenic role for PBC, the discrepant results between IgA and IgA1 class anti-2-OADC should be further assessed to investigate different functional activities depending on their molecular form.
Howson, Joanna M.M.; Stevens, Helen; Smyth, Deborah J.; Walker, Neil M.; Chandler, Kyla A.; Bingley, Polly J.; Todd, John A.
OBJECTIVE A major feature of type 1 diabetes is the appearance of islet autoantibodies before diagnosis. However, although the genetics of type 1 diabetes is advanced, the genetics of islet autoantibodies needs further investigation. The primary susceptibility loci in type 1 diabetes, the HLA class I and II genes, are believed to determine the specificity and magnitude of the autoimmune response to islet antigens. We investigated the association of glutamic acid decarboxylase autoantibodies (GADA) and insulinoma-associated antigen-2 autoantibodies (IA-2A) with the HLA region. RESEARCH DESIGN AND METHODS Associations of GADA and IA-2A with HLA-DRB1, HLA-DQB1, HLA-B, HLA-C, HLA-A, MICA, and 3,779 single nucleotide polymorphisms (SNPs) were analyzed in 2,531 childhood-onset case subjects (median time since diagnosis 5 years). All analyses were adjusted for age-at-diagnosis and duration of diabetes. RESULTS GADA and IA-2A were associated with an older age-at-diagnosis (P < 10−19). For GADA, the primary association was with HLA-DQB1 (P = 9.00 × 10−18), with evidence of a second independent effect in the HLA class I region with SNP, rs9266722 (P = 2.84 × 10−6). HLA-DRB1 had the strongest association with IA-2A (P = 1.94 × 10−41), with HLA-A*24 adding to the association, albeit negatively (P = 1.21 × 10−10). There was no evidence of association of either IA-2A or GADA with the highly type 1 diabetes predisposing genotype, HLA-DRB1*03/04. CONCLUSIONS Despite genetic association of type 1 diabetes and the islet autoantibodies localizing to the same HLA class II genes, HLA-DRB1 and HLA-DQB1, the effects of the class II alleles and genotypes involved are quite different. Therefore, the presence of autoantibodies is unlikely to be causal, and their role in pathogenesis remains to be established. PMID:21831970
Matheson, Louise S; Osborn, Michael J; Smith, Jennifer A; Corcos, Daniel; Hamon, Maureen; Chaouaf, Rima; Coadwell, John; Morgan, Geoff; Oxley, David; Brüggemann, Marianne
Recently, we identified that diverse heavy chain (H-chain)-only IgG is spontaneously produced in light chain (L-chain)-deficient mice (L(-/-) with silenced kappa and lambda loci) despite a block in B cell development. In murine H-chain IgG, the first Cgamma exon, C(H)1, is removed after DNA rearrangement and secreted polypeptides are comparable with camelid-type H-chain IgG. Here we show that L(-/-) mice generate a novel class of H-chain Ig with covalently linked alpha chains, not identified in any other healthy mammal. Surprisingly, diverse H-chain-only IgA can be released from B cells at levels similar to conventional IgA and is found in serum and sometimes in milk and saliva. Surface IgA without L-chain is expressed in B220(+) spleen cells, which exhibited a novel B cell receptor, suggesting that associated conventional differentiation events occur. To facilitate the cellular transport and release of H-chain-only IgA, chaperoning via BiP association seems to be prevented as only alpha chains lacking C(H)1 are released from the cell. This appears to be accomplished by imprecise class-switch recombination (CSR) from Smu into the alpha constant region, which removes all or part of the Calpha1 exon at the genomic level.
Esteve, M; Mallolas, J; Klaassen, J; Abad-Lacruz, A; Gonzàlez-Huix, F; Cabré, E; Fernández-Bañares, F; Menacho, M; Condom, E; Martí-Ragué, J; Gassull, M A
Few studies have assessed the IgA antineutrophil cytoplasmic antibody (ANCA) positivity in ulcerative colitis patients and there is no information about factors related to its synthesis and its status after colectomy. The aims of the study were to assess the serum IgA ANCA prevalence in ulcerative colitis patients, both nonoperated and operated, and to determine the clinical factors related to this positivity. Fifty-four ulcerative colitis patients, 63 ulcerative colitis colectomized patients (32 with Brooke's ileostomy and 31 with ileal pouch anal anastomosis), and 24 controls were studied. Antineutrophil cytoplasmic antibodies were detected by specific indirect immunofluorescent assays. The percentage of IgA ANCA was significantly higher in patients with ileal pouch anal anastomosis (45%) than in patients with Brooke's ileostomy (22%). There were no differences related to the presence of pouchitis in ileal pouch anal anastomosis patients. Patients with nonoperated extensive colitis (47%) had a significantly higher percentage of IgA ANCA than patients with proctitis (19%). Total percentage of ANCA (IgA and/or IgG) tended to be higher in ulcerative colitis and in patients with ileal pouch anal anastomosis than in patients with Brooke's ileostomy. However, in ileal pouch anal anastomosis patients, ANCA positivity was mainly due to exclusive IgA production. A substantial percentage of ulcerative colitis patients, and especially colectomized patients with ileal pouch anal anastomosis, had IgA ANCA, suggesting that ANCA production in ulcerative colitis might be stimulated by an immune reaction in the intestinal mucosa.
Bergqvist, Peter; Stensson, Anneli; Lycke, Nils Y; Bemark, Mats
Recently, we reported that CD40(-/-) mice, exhibiting exclusively T cell-independent IgA class switch recombination (CSR), demonstrated near normal levels of IgA plasma cells in the gut lamina propria (LP), despite the complete lack of germinal centers (GCs). In this study, we have extended our analysis focusing on how to reconcile these findings using flow cytometry and molecular markers for IgA CSR. In agreement with our previous results with small intestinal LP, the colon LP was found to host IgA CSR only when lymphoid follicles were present. Thus, no IgA CSR was observed in the nonorganized colon LP. By contrast, the Peyer's patch (PP) was the dominant IgA CSR site in both CD40(-/-) and wild type (WT) mice, and they both hosted similar levels of mRNA expression for B cell activating factor of the TNF family, a proliferation inducing ligand, and inducible NO synthase, potential switch-factors for IgA. Unexpectedly, we found that PP B cells undergoing IgA CSR were GL7-intermediate. These cells had not undergone somatic hypermutations (SHMs), whereas GL7-high cells in WT PP, which exhibited GCs, were heavily mutated. Moreover, IgA plasma cells in the LP of CD40(-/-) mice demonstrated few mutations in their Ig V regions, whereas WT LP B cells from different sites showed extensive SHMs, which were also clonally related. Therefore, IgA CSR can occur in PP at a stage preceding manifest GC (GL7-intermediate), whereas SHM require GC formations (GL7-high). These findings reconcile that IgA CSR can occur in PP in the absence of GC with the fact that CD40(-/-) mice host near normal levels of IgA plasma cells in the LP.
Kreisel, W; Siegel, A; Bahler, A; Spamer, C; Schiltz, E; Kist, M; Seilnacht, G; Klein, R; Berg, P A; Heilmann, C
In a preliminary study we showed that antibodies to the endoplasmic reticulum protein calreticulin (CR) occur in primary biliary cirrhosis (PBC) and autoimmune hepatitis type 1 (AIH). Since anti-CR antibodies have also been found in patients with infectious diseases, we investigated their prevalence and immunoglobulin classes in patients with various hepatic and intestinal diseases, hoping to get some information on a possible relationship between an infectious trigger and the induction of a certain class of anti-CR antibodies. Sera were tested for anti-CR antibodies of the IgA, IgG, and IgM class by Western blotting, using CR isolated from human liver: in autoimmune liver diseases (primary biliary cirrhosis (PBC) (n = 86) and autoimmune hepatitis (AIH) type 1 (n = 57)), alcoholic liver cirrhosis (ALC) (n = 32), viral liver infections (acute hepatitis A (n = 8), acute hepatitis B (n = 20), and chronic hepatitis C (n = 28)), and intestinal diseases (Crohn disease (CD) (n = 30), acute yersiniosis (n = 26)). Sera from 100 healthy individuals served as negative controls. The most prominent finding was the high prevalence of anti-CR antibodies of the IgA class and the similarity in the anti-CR antibody class pattern in PBC (IgA, 62%; IgG, 43%; IgM, 55%) and yersiniosis (IgA, 62%; IgG, 39%; IgM, 42%). Class IgA anti-CR antibodies also occurred frequently in ALC (IgA, 44%; IgG, 41%; IgM, 19%). In contrast, in AIH anti-CR antibodies were predominantly of class IgG (IgA, 28%; IgG, 60%; IgM, 33%). In hepatitis A anti-CR antibodies were absent. In the other diseases they had a low prevalence and were mostly of class IgG (acute hepatitis B: IgA, 0%; IgG, 15%; IgM, 0%; chronic hepatitis C: IgA, 7%; IgG, 21%; IgM, 0%; CD: IgA, 13%; IgG, 20%; IgM, 13%). Of the healthy individuals 7% had anti-CR antibodies exclusively of class IgG. The high prevalence of anti-CR antibodies of class IgA in patients with PBC and yersiniosis as well as in alcoholic liver disease reflects a reactivity
Kataoka, Kosuke; Fujihashi, Keiko; Terao, Yutaka; Gilbert, Rebekah S; Sekine, Shinichi; Kobayashi, Ryoki; Fukuyama, Yoshiko; Kawabata, Shigetada; Fujihashi, Kohtaro
Native cholera toxin (nCT) as a nasal adjuvant was shown to elicit increased levels of T-independent S-IgA antibody (Ab) responses through IL-5- IL-5 receptor interactions between CD4+ T cells and IgA+ B-1 B cells in murine submandibular glands (SMGs) and nasal passages (NPs). Here, we further investigate whether oral-nasopharyngeal dendritic cells (DCs) play a central role in the induction of B-1 B cell IgA class switch recombination (CSR) for the enhancement of T cell-independent (TI) mucosal S-IgA Ab responses. High expression levels of activation-induced cytidine deaminase, Iα-Cμ circulation transcripts and Iμ-Cα transcripts were seen on B-1 B cells purified from SMGs and NPs of both TCRβ⁻/⁻ mice and wild-type mice given nasal trinitrophenyl (TNP)-LPS plus nCT, than in the same tissues of mice given nCT or TNP-LPS alone. Further, DCs from SMGs, NPs and NALT of mice given nasal TNP-LPS plus nCT expressed significantly higher levels of a proliferation-inducing ligand (APRIL) than those in mice given TNP-LPS or nCT alone, whereas the B-1 B cells in SMGs and NPs showed elevated levels of transmembrane activator and calcium modulator cyclophilin ligand interactor (TACI) expression. Interestingly, high frequencies of IgA+ B-1 B cells were induced when peritoneal IgA⁻ IgM+ B cells were stimulated with mucosal DCs from mice given nasal TNP-LPS plus nCT. Taken together, these findings show that nasal nCT plays a key role in the enhancement of mucosal DC-mediated TI IgA CSR by B-1 B cells through their interactions with APRIL and TACI.
Ruane, Darren; Chorny, Alejo; Lee, Haekyung; Faith, Jeremiah; Pandey, Gaurav; Shan, Meimei; Simchoni, Noa; Rahman, Adeeb; Garg, Aakash; Weinstein, Erica G.; Oropallo, Michael; Gaylord, Michelle; Ungaro, Ryan; Cunningham-Rundles, Charlotte; Alexandropoulos, Konstantina; Mucida, Daniel; Merad, Miriam; Cerutti, Andrea
Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103+ and CD24+CD11b+ DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell–dependent or –independent pathways. Compared with lung DCs (LDC), lung CD64+ macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid–dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT–specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs. PMID:26712806
Ruane, Darren; Chorny, Alejo; Lee, Haekyung; Faith, Jeremiah; Pandey, Gaurav; Shan, Meimei; Simchoni, Noa; Rahman, Adeeb; Garg, Aakash; Weinstein, Erica G; Oropallo, Michael; Gaylord, Michelle; Ungaro, Ryan; Cunningham-Rundles, Charlotte; Alexandropoulos, Konstantina; Mucida, Daniel; Merad, Miriam; Cerutti, Andrea; Mehandru, Saurabh
Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103(+) and CD24(+)CD11b(+) DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell-dependent or -independent pathways. Compared with lung DCs (LDC), lung CD64(+) macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid-dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT-specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs. © 2016 Ruane et al.
Lai, Kar Neng; Tang, Sydney C W; Schena, Francesco Paolo; Novak, Jan; Tomino, Yasuhiko; Fogo, Agnes B; Glassock, Richard J
Globally, IgA nephropathy (IgAN) is the most common primary glomerulonephritis that can progress to renal failure. The exact pathogenesis of IgAN is not well defined, but current biochemical and genetic data implicate overproduction of aberrantly glycosylated IgA1. These aberrant immunoglobulins are characterized by galactose deficiency of some hinge-region O-linked glycans. However, aberrant glycosylation alone is insufficient to induce renal injury: the participation of glycan-specific IgA and IgG autoantibodies that recognize the undergalactosylated IgA1 molecule is required. Glomerular deposits of immune complexes containing undergalactosylated IgA1 activate mesangial cells, leading to the local overproduction of cytokines, chemokines and complement. Emerging data indicate that mesangial-derived mediators that are released following mesangial deposition of IgA1 lead to podocyte and tubulointerstitial injury via humoral crosstalk. Patients can present with a range of signs and symptoms, from asymptomatic microscopic haematuria to macroscopic haematuria. The clinical progression varies, with 30-40% of patients reaching end-stage renal disease 20-30 years after the first clinical presentation. Currently, no IgAN-specific therapies are available and patients are managed with the aim of controlling blood pressure and maintaining renal function. However, new therapeutic approaches are being developed, building upon our ever-improving understanding of disease pathogenesis.
Mestecky, Jiri; Novak, Jan; Moldoveanu, Zina; Raska, Milan
IgA nephropathy (IgAN) is the leading cause of primary glomerulonephritis in the world. The disease is characterized by the presence of IgA-containing immune complexes in the circulation and in mesangial deposits with ensuing glomerular injury. Although in humans there are two IgA subclasses, only IgA1 molecules are involved. The exclusivity of participation of IgA1 in IgAN prompted extensive structural and immunological studies of the unique hinge region (HR) of IgA1, which is absent in otherwise highly homologous IgA2. HR of IgA1 with altered O-glycans serves as an antigen recognized by autoantibodies specific for aberrant HR glycans leading to the generation of nephritogenic immune complexes. However, there are several unresolved questions concerning the phylogenetic origin of human IgA1 HR, the structural basis of its antigenicity, the origin of antibodies specific for HR with altered glycan moieties, the regulatory defects in IgA1 glycosylation pathways, and the potential approaches applicable to the disease-specific interventions in the formation of nephritogenic immune complexes. This review focuses on the gaps in our knowledge of molecular and cellular events that are involved in the immunopathogenesis of IgAN.
Rodriguez-Reyna, Tatiana S; Mercado-Velázquez, Pamela; Yu, Neng; Alosco, Sharon; Ohashi, Marina; Lebedeva, Tatiana; Cruz-Lagunas, Alfredo; Núñez-Álvarez, Carlos; Cabiedes-Contreras, Javier; Vargas-Alarcón, Gilberto; Granados, Julio; Zúñiga, Joaquin; Yunis, Edmond
Human leukocyte antigen (HLA) polymorphism studies in Systemic Sclerosis (SSc) have yielded variable results. These studies need to consider the genetic admixture of the studied population. Here we used our previously reported definition of genetic admixture of Mexicans using HLA class I and II DNA blocks to map genetic susceptibility to develop SSc and its complications. We included 159 patients from a cohort of Mexican Mestizo SSc patients. We performed clinical evaluation, obtained SSc-associated antibodies, and determined HLA class I and class II alleles using sequence-based, high-resolution techniques to evaluate the contribution of these genes to SSc susceptibility, their correlation with the clinical and autoantibody profile and the prevalence of Amerindian, Caucasian and African alleles, blocks and haplotypes in this population. Our study revealed that class I block HLA-C*12:03-B*18:01 was important to map susceptibility to diffuse cutaneous (dc) SSc, HLA-C*07:01-B*08:01 block to map the susceptibility role of HLA-B*08:01 to develop SSc, and the C*07:02-B*39:05 and C*07:02-B*39:06 blocks to map the protective role of C*07:02 in SSc. We also confirmed previous associations of HLA-DRB1*11:04 and -DRB1*01 to susceptibility to develop SSc. Importantly, we mapped the protective role of DQB1*03:01 using three Amerindian blocks. We also found a significant association for the presence of anti-Topoisomerase I antibody with HLA-DQB1*04:02, present in an Amerindian block (DRB1*08:02-DQB1*04:02), and we found several alleles associated to internal organ damage. The admixture estimations revealed a lower proportion of the Amerindian genetic component among SSc patients. This is the first report of the diversity of HLA class I and II alleles and haplotypes Mexican patients with SSc. Our findings suggest that HLA class I and class II genes contribute to the protection and susceptibility to develop SSc and its different clinical presentations as well as different
Rodriguez-Reyna, Tatiana S.; Mercado-Velázquez, Pamela; Yu, Neng; Alosco, Sharon; Ohashi, Marina; Lebedeva, Tatiana; Cruz-Lagunas, Alfredo; Núñez-Álvarez, Carlos; Vargas-Alarcón, Gilberto; Granados, Julio; Zúñiga, Joaquin; Yunis, Edmond
Introduction Human leukocyte antigen (HLA) polymorphism studies in Systemic Sclerosis (SSc) have yielded variable results. These studies need to consider the genetic admixture of the studied population. Here we used our previously reported definition of genetic admixture of Mexicans using HLA class I and II DNA blocks to map genetic susceptibility to develop SSc and its complications. Methods We included 159 patients from a cohort of Mexican Mestizo SSc patients. We performed clinical evaluation, obtained SSc-associated antibodies, and determined HLA class I and class II alleles using sequence-based, high-resolution techniques to evaluate the contribution of these genes to SSc susceptibility, their correlation with the clinical and autoantibody profile and the prevalence of Amerindian, Caucasian and African alleles, blocks and haplotypes in this population. Results Our study revealed that class I block HLA-C*12:03-B*18:01 was important to map susceptibility to diffuse cutaneous (dc) SSc, HLA-C*07:01-B*08:01 block to map the susceptibility role of HLA-B*08:01 to develop SSc, and the C*07:02-B*39:05 and C*07:02-B*39:06 blocks to map the protective role of C*07:02 in SSc. We also confirmed previous associations of HLA-DRB1*11:04 and –DRB1*01 to susceptibility to develop SSc. Importantly, we mapped the protective role of DQB1*03:01 using three Amerindian blocks. We also found a significant association for the presence of anti-Topoisomerase I antibody with HLA-DQB1*04:02, present in an Amerindian block (DRB1*08:02-DQB1*04:02), and we found several alleles associated to internal organ damage. The admixture estimations revealed a lower proportion of the Amerindian genetic component among SSc patients. Conclusion This is the first report of the diversity of HLA class I and II alleles and haplotypes Mexican patients with SSc. Our findings suggest that HLA class I and class II genes contribute to the protection and susceptibility to develop SSc and its different clinical
Nagaraju, Kanneboyina; Raben, Nina; Loeffler, Lisa; Parker, Tomasina; Rochon, Paul J.; Lee, Eunice; Danning, Carol; Wada, Ryuichi; Thompson, Cynthia; Bahtiyar, Gul; Craft, Joseph; Hooft van Huijsduijnen, Rob; Plotz, Paul
In the human inflammatory myopathies (polymyositis and dermatomyositis), the early, widespread appearance of MHC class I on the surface of muscle cells and the occurrence of certain myositis-specific autoantibodies are striking features. We have used a controllable muscle-specific promoter system to up-regulate MHC class I in the skeletal muscles of young mice. These mice develop clinical, biochemical, histological, and immunological features very similar to human myositis. The disease is inflammatory, limited to skeletal muscles, self-sustaining, more severe in females, and often accompanied by autoantibodies, including, in some mice, autoantibodies to histidyl-tRNA synthetase, the most common specificity found in the spontaneous human disease, anti-Jo-1. This model suggests that an autoimmune disease may unfold in a highly specific pattern as the consequence of an apparently nonspecific event—the sustained up-regulation of MHC class I in a tissue—and that the specificity of the autoantibodies derives not from the specificity of the stimulus, but from the context, location, and probably the duration of the stimulus. This model further suggests that the presumed order of events as an autoimmune disease develops needs to be reconsidered. PMID:10922072
López-Mejías, Raquel; Carmona, F David; Castañeda, Santos; Genre, Fernanda; Remuzgo-Martínez, Sara; Sevilla-Perez, Belén; Ortego-Centeno, Norberto; Llorca, Javier; Ubilla, Begoña; Mijares, Verónica; Pina, Trinitario; Miranda-Filloy, José A; Navas Parejo, Antonio; de Argila, Diego; Aragües, Maximiliano; Rubio, Esteban; Luque, Manuel León; Blanco-Madrigal, Juan María; Galíndez-Aguirregoikoa, Eva; Jayne, David; Blanco, Ricardo; Martín, Javier; González-Gay, Miguel A
The genetic component of Immunoglobulin-A (IgA) vasculitis is still far to be elucidated. To increase the current knowledge on the genetic component of this vasculitis we performed the first genome-wide association study (GWAS) on this condition. 308 IgA vasculitis patients and 1,018 healthy controls from Spain were genotyped by Illumina HumanCore BeadChips. Imputation of GWAS data was performed using the 1000 Genomes Project Phase III dataset as reference panel. After quality control filters and GWAS imputation, 285 patients and 1,006 controls remained in the datasets and were included in further analysis. Additionally, the human leukocyte antigen (HLA) region was comprehensively studied by imputing classical alleles and polymorphic amino acid positions. A linkage disequilibrium block of polymorphisms located in the HLA class II region surpassed the genome-wide level of significance (OR = 0.56, 95% CI = 0.46-0.68). Although no polymorphic amino acid positions were associated at the genome-wide level of significance, P-values of potential relevance were observed for the positions 13 and 11 of HLA-DRB1 (P = 6.67E-05, P = 1.88E-05, respectively). Outside the HLA, potential associations were detected, but none of them were close to the statistical significance. In conclusion, our study suggests that IgA vasculitis is an archetypal HLA class II disease.
Mariaselvam, C M; Fortier, C; Charron, D; Krishnamoorthy, R; Tamouza, R; Negi, V S
Rheumatoid arthritis (RA) is a complex multifactorial autoimmune disease characterized by inflammatory arthritis. The precise etiology and pathogenesis of RA remains elusive but evidence points towards stochastic interactions between genetic and environmental factors. This study investigated the distribution of human leucocyte antigen (HLA)-DRB1/DQB1 alleles in South Indian patients with rheumatoid arthritis (RA) and their influence on RA susceptibility and clinical phenotype. Low resolution HLA-DRB1 and -DQB1 typing was performed in 271 RA patients and 233 healthy controls by polymerase chain reaction (PCR) using sequence-specific primers (SSP). HLA-DRB1*10 was found to be more frequent in patients (Pc = 0.004, OR = 2.23, 95% CI = 1.5-3.34) than controls. This difference persisted in RF positive (Pc = 9 × 10(-6) , OR = 2.45, 95% CI = 1.62-3.74), ACPA positive (Pc = 0.007, OR = 2.10, 95% CI = 1.35-3.29), ACPA negative (Pc = 0.001, OR = 2.45, 95% CI = 1.50-3.97) and both RF and ACPA positive subgroup of patients (Pc = 0.003, OR = 2.22, 95% CI = 1.41-3.51). On the contrary, the HLA-DRB1*13 (Pc = 0.01, OR = 0.43, 95% CI = 0.25-0.73) and HLA-DRB1*14 (Pc = 0.003, OR = 0.43, 95% CI = 0.26-0.69) alleles were over-represented in controls than patients. Further, distribution of the prominent Caucasian RA risk allele DRB1*04 did not differ between patients and controls in our study population. We did not find any association between DQB1 alleles and RA susceptibility or autoantibody status. The haplotypes DQB1*05-DRB1*10 (P = 6.8 × 10(-6) , OR = 2.46, 95% CI = 1.63-3.79) and DQB1*06-DRB1*15 (P = 0.03, OR = 1.41, 95% CI = 1.02-1.96) were more frequent in patients while DQB1*05-DRB1*14 (P = 8.4 × 10(-4) , OR = 0.44, 95% CI = 0.26-0.74) and DQB1*06-DRB1*13 (P = 9.5 × 10(-4) , OR = 0.40, 95% CI = 0.21-0.72) were higher in controls. To conclude, HLA-DRB1*10 is associated with RA while HLA-DRB1*13 and HLA-DRB1*14 alleles confer protection in south Indian Tamils.
Graham, Robert R; Ortmann, Ward; Rodine, Peter; Espe, Karl; Langefeld, Carl; Lange, Ethan; Williams, Adrienne; Beck, Stephanie; Kyogoku, Chieko; Moser, Kathy; Gaffney, Patrick; Gregersen, Peter K; Criswell, Lindsey A; Harley, John B; Behrens, Timothy W
The human leukocyte antigen (HLA) Class II antigen presentation alleles DR and DQ are associated with susceptibility to systemic lupus erythematosus (SLE) and the production of lupus-related autoantibodies. Here, we explore the effect of different combinations of Class II risk haplotypes in a large, multi-center collection of 780 SLE families. Haplotypes bearing the DRB1*1501/DQB1*0602 (DR2) and DRB1*0301/DQB1*0201 (DR3) alleles were present in nearly two-thirds of SLE cases and were significantly associated with disease susceptibility in both family-based and case-control study designs. DR3-containing haplotypes conferred higher risk for disease than DR2, and individual homozygous for DR3 or compound heterozygous for DR3 and DR2 showed the highest risk profile. DR2 haplotypes were also found to be associated with antibodies to the nuclear antigen Sm, and, as previously observed, DR3 genotypes were associated with Ro and La autoantibodies. Interestingly, SLE cases and unaffected family members who were DR2/DR3 compound heterozygotes showed particularly strong risk of developing antibodies to Ro, and were enriched for La and Sm. These data provide convincing evidence that particular combinations of HLA Class II DR2 and DR3 haplotypes are key determinants of autoantibody production and disease susceptibility in human SLE.
Cooling, Laura L; Sherbeck, John; Mowers, Jonathon C; Hugan, Sheri L
Ipilimumab, nivolumab, and pembrolizumab represent a new class of immunotherapeutic drugs for treating patients with advanced cancer. Known as checkpoint inhibitors, these drugs act to upregulate the cellular and humoral immune response to tumor antigens by inhibiting T-cell autoregulation. As a consequence, they can be associated with immune-related adverse events (irAEs) due to loss of self-tolerance, including rare cases of immune-related cytopenias. We performed a retrospective clinical chart review, including serologic, hematology, and chemistry laboratory results, of two patients who developed red blood cell (RBC) autoantibodies during treatment with a checkpoint inhibitor. Serologic testing of blood samples from these patients during induction therapy with ipilimumab and nivolumab, respectively, showed their RBCs to be positive by the direct antiglobulin test (IgG+, C3+) and their plasma to contain panreactive RBC autoantibodies. Neither patient had evidence of hemolysis. Both patients developed an additional irAE during treatment. A literature review for patients who had developed immune-mediated cytopenia following treatment with a checkpoint inhibitor was performed. Nine other patients were reported with a hematologic irAE, including six with anemia attributable to autoimmune anemia, aplastic anemia, or pure RBC aplasia. Hematologic irAEs tend to occur early during induction therapy, often coincident with irAEs of other organs. In conclusion, checkpoint inhibitors can be associated with the development of autoantibodies, immune-mediated cytopenias, pure RBC aplasia, and aplastic anemia. Immunohematology reference laboratories should be aware of these agents when evaluating patients with advanced cancer and new-onset autoantibodies, anemia, and other cytopenias.
Lechner, Sebastian M; Abbad, Lilia; Boedec, Erwan; Papista, Christina; Le Stang, Marie-Bénédicte; Moal, Christelle; Maillard, Julien; Jamin, Agnès; Bex-Coudrat, Julie; Wang, Yong; Li, Aiqun; Martini, Paolo G V; Monteiro, Renato C; Berthelot, Laureline
IgA nephropathy (IgAN), characterized by mesangial IgA1 deposits, is a leading cause of renal failure worldwide. IgAN pathogenesis involves circulating hypogalactosylated IgA1 complexed with soluble IgA Fc receptor I (sCD89) and/or anti-hypogalactosylated-IgA1 autoantibodies, but no specific treatment is available for IgAN. The absence of IgA1 and CD89 homologs in the mouse has precluded in vivo proof-of-concept studies of specific therapies targeting IgA1. However, the α1KI‑CD89Tg mouse model of IgAN, which expresses human IgA1 and human CD89, allows in vivo testing of recombinant IgA1 protease (IgA1‑P), a bacterial protein that selectively cleaves human IgA1. Mice injected with IgA1‑P (1-10 mg/kg) had Fc fragments of IgA1 in both serum and urine, associated with a decrease in IgA1-sCD89 complexes. Levels of mesangial IgA1 deposits and the binding partners of these deposits (sCD89, transferrin receptor, and transglutaminase 2) decreased markedly 1 week after treatment, as did the levels of C3 deposition, CD11b(+) infiltrating cells, and fibronectin. Antiprotease antibodies did not significantly alter IgA1‑P activity. Moreover, hematuria consistently decreased after treatment. In conclusion, IgA1‑P strongly diminishes human IgA1 mesangial deposits and reduces inflammation, fibrosis, and hematuria in a mouse IgAN model, and therefore may be a plausible treatment for patients with IgAN. Copyright © 2016 by the American Society of Nephrology.
Hastings, Margaret Colleen; Moldoveanu, Zina; Suzuki, Hitoshi; Berthoux, Francois; Julian, Bruce A; Sanders, John T; Renfrow, Matthew B; Novak, Jan; Wyatt, Robert J
Introduction IgA nephropathy, the most prevalent glomerular disease in the world, requires a renal biopsy for diagnosis. Reliable biomarkers are needed for the non-invasive diagnosis of this disease and to more fully delineate its natural history and risk for progression. Areas covered In this review, the authors examine serum levels of galactose-deficient IgA1 (Gd-IgA1) and glycan-specific IgG and IgA autoantibodies that are integral to pathogenesis of IgA nephropathy. They also explore biomarkers related to alternative and lectin pathways of complement activation and serum and urinary peptide biomarkers detected by mass spectrometric methods. The literature search included review of all publications having IgA nephropathy in the title that were cited in PubMed and Scopus over the past 10 years and a non-systematic review of abstracts published for the annual meetings of the American Society of Nephrology and the International Symposia on IgA Nephropathy. Expert opinion Serum Gd-IgA1 level and glycan-specific autoantibody levels are prime candidates to become diagnostic biomarkers for IgA nephropathy because of their central role in the earliest stages of disease pathogenesis. Assays for serum levels of complement proteins C3 and factor H are readily available in clinical practice and deserve continued study, either alone or in tandem with total serum IgA or serum Gd-IgA1 levels, as prognostic biomarkers for patients with IgA nephropathy. Urinary peptidomic data are also reviewed because this approach can successfully differentiate patients with IgA nephropathy from healthy controls and from patients with other forms of renal disease. PMID:24175678
Papp, Maria; Sipeki, Nora; Vitalis, Zsuzsanna; Tornai, Tamas; Altorjay, Istvan; Tornai, Istvan; Udvardy, Miklos; Fechner, Kai; Jacobsen, Silvia; Teegen, Bianca; Sumegi, Andrea; Veres, Gabor; Lakatos, Peter Laszlo; Kappelmayer, Janos; Antal-Szalmas, Peter
Anti-neutrophil cytoplasmic antibodies (ANCA) are a non-uniform family of antibodies recognizing diverse components of neutrophil granulocytes. ANCA formation might be induced by protracted bacterial infections or probably reflect an abnormal immune response to commensal microorganisms. Bacterial infections are common complications in cirrhosis with high incidence of episodes caused by enteric organisms, therefore, we sought to study the presence and clinical importance of ANCA in cirrhosis. Sera of 385 patients with cirrhosis of different etiologies were assayed for ANCA of IgG, IgA, IgA1, IgA2, and secretory IgA subtypes by indirect immunofluorescence and ELISAs. The control group comprised 202 patients with chronic liver diseases without cirrhosis and 100 healthy subjects. In cirrhosis, a 2-year follow-up, observational study was conducted to assess a possible association between the presence of ANCA and clinically significant bacterial infections. Prevalence of ANCA IgA was significantly higher in cirrhosis (52.2%) compared to chronic liver diseases (18.6%) or healthy controls (0%, p<0.001 for both). ANCA IgA subtyping assays revealed marked increase in the proportion of IgA2 subtype (46% of total ANCA IgA) and presence of the secretory component concurrently. Presence of ANCA IgA was associated with disease-specific clinical characteristics (Child-Pugh stage and presence of ascites, p<0.001). During a 2-year follow-up period, risk of infections was higher among patients with ANCA IgA compared to those without (41.8% vs. 23.4%, p<0.001). ANCA IgA positivity was associated with a shorter time to the first infectious complication (pLogRank <0.001) in Kaplan-Meier analysis and was identified as an independent predictor in multivariate Cox-regression analysis (HR:1.74, 95% CI: 1.18-2.56, p=0.006). Presence of IgA type ANCA is common in cirrhosis. Involvement of gut mucosal immune system is in center of their formation and probably reflects sustained exposure to
Furukawa, Hiroshi; Oka, Shomi; Shimada, Kota; Masuo, Kiyoe; Nakajima, Fumiaki; Funano, Shunichi; Tanaka, Yuki; Komiya, Akiko; Fukui, Naoshi; Sawasaki, Tatsuya; Tadokoro, Kenji; Nose, Masato; Tsuchiya, Naoyuki; Tohma, Shigeto
Interstitial lung disease (ILD) is frequently associated with collagen disease. It is then designated as collagen vascular disease-associated ILD (CVD-ILD), and influences patients’ prognosis. The prognosis of acute-onset diffuse ILD (AoDILD) occurring in patients with collagen disease is quite poor. Here, we report our investigation of auto-antibody (Ab) profiles to determine whether they may be useful in diagnosing CVD-ILD or AoDILD in collagen disease. Auto-Ab profiles were analyzed using the Lambda Array Beads Multi-Analyte System, granulocyte immunofluorescence test, Proto-Array Human Protein Microarray, AlphaScreen assay, and glutathione S-transferase capture enzyme-linked immunosorbent assay in 34 patients with rheumatoid arthritis (RA) with or without CVD-ILD and in 15 patients with collagen disease with AoDILD. The average anti-major histocompatibility complex class I-related chain A (MICA) Ab levels were higher in RA patients with CVD-ILD than in those without (P = 0.0013). The ratio of the average anti-MICA Ab level to the average anti-human leukocyte antigen class I Ab level (ie, MICA/Class I) was significantly higher in RA patients with CVD-ILD compared with those without (P = 4.47 × 10−5). To the best of our knowledge, this is the first report of auto-Ab profiles in CVD-ILD. The MICA/Class I ratio could be a better marker for diagnosing CVD-ILD than KL-6 (Krebs von den lungen-6). PMID:26327779
Furukawa, Hiroshi; Oka, Shomi; Shimada, Kota; Masuo, Kiyoe; Nakajima, Fumiaki; Funano, Shunichi; Tanaka, Yuki; Komiya, Akiko; Fukui, Naoshi; Sawasaki, Tatsuya; Tadokoro, Kenji; Nose, Masato; Tsuchiya, Naoyuki; Tohma, Shigeto
Interstitial lung disease (ILD) is frequently associated with collagen disease. It is then designated as collagen vascular disease-associated ILD (CVD-ILD), and influences patients' prognosis. The prognosis of acute-onset diffuse ILD (AoDILD) occurring in patients with collagen disease is quite poor. Here, we report our investigation of auto-antibody (Ab) profiles to determine whether they may be useful in diagnosing CVD-ILD or AoDILD in collagen disease. Auto-Ab profiles were analyzed using the Lambda Array Beads Multi-Analyte System, granulocyte immunofluorescence test, Proto-Array Human Protein Microarray, AlphaScreen assay, and glutathione S-transferase capture enzyme-linked immunosorbent assay in 34 patients with rheumatoid arthritis (RA) with or without CVD-ILD and in 15 patients with collagen disease with AoDILD. The average anti-major histocompatibility complex class I-related chain A (MICA) Ab levels were higher in RA patients with CVD-ILD than in those without (P = 0.0013). The ratio of the average anti-MICA Ab level to the average anti-human leukocyte antigen class I Ab level (ie, MICA/Class I) was significantly higher in RA patients with CVD-ILD compared with those without (P = 4.47 × 10(-5)). To the best of our knowledge, this is the first report of auto-Ab profiles in CVD-ILD. The MICA/Class I ratio could be a better marker for diagnosing CVD-ILD than KL-6 (Krebs von den lungen-6).
Lorin, Valérie; Mouquet, Hugo
Immunoglobulin A (IgA) is the most abundant antibody isotype produced in humans. IgA antibodies primarily ensure immune protection of mucosal surfaces against invading pathogens, but also circulate and are present in large quantities in blood. IgAs are heterogeneous at a molecular level, with two IgA subtypes and the capacity to form multimers by interacting with the joining (J) chain. Here, we have developed an efficient strategy to rapidly generate human IgA1 and IgA2 monoclonal antibodies in their monomeric and dimeric forms. Recombinant monomeric and dimeric IgA1/IgA2 counterparts of a prototypical IgG1 monoclonal antibody, 10-1074, targeting the HIV-1 envelope protein, were produced in large amounts after expression cloning and transient transfection of 293-F cells. 10-1074 IgAs were FPLC-purified using a novel affinity-based resin engrafted with anti-IgA chimeric Fabs, followed by a monomers/multimers separation using size exclusion-based FPLC. ELISA binding experiments confirmed that the artificial IgA class switching of 10-1074 did not alter its antigen recognition. In summary, our technical approach allows the very efficient production of various forms of purified recombinant human IgA molecules, which are precious tools in dissecting IgA B-cell responses in physiological and pathophysiological conditions, and studying the biology, function and therapeutic potential of IgAs.
Shindi, Reham; Almehairi, Amna; Negm, Ola H; Kalsheker, Noor; Gale, Nichola S; Shale, Dennis J; Harrison, Timothy W; Bolton, Charlotte E; John, Michelle; Todd, Ian; Tighe, Patrick J; Fairclough, Lucy C
Autoimmunity occurs in chronic obstructive pulmonary disease (COPD). We describe an antigen microarray for detecting serum autoantibodies (AAbs) to determine how IgM, as well as IgG, AAbs distinguish patients with COPD from controls with a history of smoking without COPD. All COPD patients' sera contained elevated levels of AAbs to some of 30 autoantigens. There were significant differences in the autoantigenic specificities of IgM AAbs compared to IgG AAbs in the COPD sera: for example, AAbs to histone and scl-70 were mainly IgG, whereas AAbs to CENP-B and La/ssB were mainly IgM; by contrast, IgM and IgG AAbs to collagen-V were equally prevalent. Thus, a combination of IgM and IgG AAbs specific for multiple autoantigens are detected in all cases of COPD at a level at which all non-COPD controls are negative for AAbs. This highlights the importance of different classes of AAbs to a range of autoantigens in COPD. Copyright © 2017. Published by Elsevier Inc.
... disease. Causes IgA is a protein, called an antibody , that helps the body fight infections. IgA nephropathy occurs when too much of this protein is deposited in the kidneys. IgA builds up inside the small blood vessels of the kidney. Structures in the kidney called glomeruli become inflamed and ...
Hayashi, Shintaro; Nagamine, Shun; Makioka, Kouki; Kusunoki, Susumu; Okamoto, Koichi
A 71-year-old woman with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with IgA-λ monoclonal gammopathy of undetermined significance (MGUS) showed the acute development of tetraplegia, respiratory failure, and a marked fluctuation of the blood pressure. Intravenous (IV) high-dose steroid therapy (methylprednisolone: 1 g/day × 3 days), followed by oral prednisolone (PSL) (40 mg/day), and IV immunoglobulin (IVIg, 0.4 g/kg/day × 5 days) administrations resulted in the amelioration of these symptoms. However, they soon relapsed, which eventually led to complete tetraplegia and the need for mechanical ventilation. At this time, serum components of IgA-λ and IgM-λ were biclonally positive. Seven courses of plasma exchange and the alternative administration of dexamethasone (12 mg/day) and methtorexate (15 mg/week) were conducted, but with no significant improvement. Nine months after admission, she showed totally-locked in syndrome. Cryo-preserved serum obtained at this time showed high titers of IgM class antibodies against ganglioside (GD3 +++, GT1a ++++, GT1b ++, GQ1b +++, and GD1b +++), which had been negative on admission. Biopsy of the left sural nerve showed moderate reductions of large and small myelinated fibers with no inflammation, no depositions of amyloid, IgG, IgA, or IgM, and teased fiber findings revealed neither myelin ovoids nor segmental demyelination. Alternatively, melphalan at 5 mg and PSL at 32 mg were administered, with no amelioration, while serum IgA-λ monoclonal protein diminished, and IgM-λ M protein positivity was continuously observed. She frequently developed sepsis; therefore, we could no longer continue any immunosupressive therapies, but monthly IVIg administrations were given. Twelve months after admission, her neurological symptoms gradually improved and she was weaned off of mechanical ventilation. Eighteen months after admission, her muscle strength corresponded to 2 on manual muscle testing
Greenberg, Steven A
Recent studies have identified circulating immunoglobulin (Ig) G autoantibodies against cytoplasmic 5'-nucleotidase 1A (cN1A; NT5C1A) in patients with inclusion body myositis (IBM), whose detection provides for an IBM blood diagnostic test. Whether or not anti-cN1A autoantibody isotypes other than IgG are present in IBM has not previously been reported. Plasma and serum samples from 205 patients (50 with and155 without IBM) were studied for the presence of IgM and IgA, in addition to IgG, anti-cN1A autoantibodies using immunoblots and enzyme-linked immunoassays (ELISAs). IgM, IgA, and IgG anti-cN1A autoantibodies were detected by ELISA with similar sensitivities (49-53%) and specificities (94-96%), but with differing patterns of autoantibody isotype presence. Combination assays of all 3 autoantibody levels improved diagnostic sensitivity to 76%. In addition to previously recognized IgG anti-cN1A autoantibodies, IBM patients have circulating IgM and IgA anti-cN1A autoantibodies. Differing patterns of these isotypes may be present and useful for diagnosis. Copyright © 2014 Wiley Periodicals, Inc.
South, Mary Ann; Cooper, Max D.; Wollheim, Frank A.; Hong, Richard; Good, Robert A.
1. Five patients with congenital or acquired agammaglobulinemia, lacking detectable IgA in serum or saliva, were transfused with 1 to 2 liters of normal plasma. In 2 of these patients IgA was demonstrated in parotid saliva collected after transfusion, but in none of the 5 was salivary IgG or IgM found. This observation indicates the selective transport of IgA into saliva. 2. The observation by others of an immunochemical difference between serum and sahvary IgA globulin was confirmed. In contrast to serum IgA, salivary IgA is attached to a protein having antigenicity which migrates as a gamma1 globulin. We have termed this protein component "transport piece". 3. The transport piece has been found in an unbound form in the saliva of persons completely lacking IgA: agammaglobulinemic patients, ataxia-telangiectasia patients, a healthy person lacking IgA, and a newborn infant. Free transport piece still occurs in the normal child's saliva after IgA production begins. By adulthood there is usually no free transport piece in the saliva. 4. Heat-aggregated salivary IgA, like heat-aggregated serum IgA, does not fix complement. 5. Our findings offer support for the view that there is a distinct local antibody system for the protection of the mucous surfaces. PMID:4160397
López-Vázquez, Antonio; Mozo, Lourdes; Alonso-Arias, Rebeca; Suárez-Álvarez, Beatriz; Vidal-Castiñeira, José Ramón; Arranz, Eduardo; Volta, Umberto; Bousoño, Carlos; López-Hoyos, Marcos; Rodrigo, Luís; López-Larrea, Carlos
Overexpression of autologous proteins can lead to the formation of autoantibodies and autoimmune diseases. MHC class I polypeptide-related sequence A (MICA) is highly expressed in the enterocytes of patients with celiac disease, which arises in response to gluten. The aim of this study was to investigate anti-MICA antibody formation in patients with celiac disease and its association with other autoimmune processes. We tested serum samples from 383 patients with celiac disease, obtained before they took up a gluten-free diet, 428 patients with diverse autoimmune diseases, and 200 controls for anti-MICA antibodies. All samples were also tested for anti-endomysium and anti-transglutaminase antibodies. Antibodies against MICA were detected in samples from 41.7% of patients with celiac disease but in only 3.5% of those from controls (P <0.0001) and 8.2% from patients with autoimmune disease (P <0.0001). These antibodies disappeared after the instauration of a gluten-free diet. Anti-MICA antibodies were significantly prevalent in younger patients (P <0.01). Fifty-eight patients with celiac disease (15.1%) presented a concomitant autoimmune disease. Anti-MICA-positive patients had a higher risk of autoimmune disease than MICA antibody-negative patients (P <0.0001; odds ratio = 6.11). The risk was even higher when we also controlled for age (odds ratio = 11.69). Finally, we found that the associated risk of developing additional autoimmune diseases was 16 and 10 times as high in pediatric patients and adults with anti-MICA, respectively, as in those without. The development of anti-MICA antibodies could be related to a gluten-containing diet, and seems to be involved in the development of autoimmune diseases in patients with celiac disease, especially younger ones.
Novak, Jan; Rizk, Dana; Takahashi, Kazuo; Zhang, XianWen; Bian, Qi; Ueda, Hiroyuki; Ueda, Yoshimi; Reily, Colin; Lai, Ling-Yun; Hao, Chuanming; Novak, Lea; Huang, Zhi-Qiang; Renfrow, Matthew B.; Suzuki, Hitoshi; Julian, Bruce A.
Background IgA nephropathy, a frequent cause of end-stage renal disease, is an autoimmune disease wherein immune complexes consisting of IgA1 with galactose-deficient O-glycans (autoantigen) and anti-glycan autoantibodies deposit in glomeruli and induce renal injury. Multiple genetic loci associated with disease risk have been identified. The prevalence of risk alleles varies geographically: it is the highest in eastern Asia and northern Europe, lower in other parts of Europe and North America, and the lowest in Africa. IgA nephropathy is diagnosed by the pathological assessment of a renal biopsy specimen. Currently, therapy is not disease targeted but rather focused on maintaining control of blood pressure and proteinuria, ideally with suppression of angiotensin II. Possible additional approaches differ between countries. Disease-specific therapy as well as new tools for the diagnosis, prognosis, and assessment of responses to therapy are needed. Summary Glycosylation pathways associated with aberrant O-glycosylation of IgA1 and, thus, production of autoantigen, have been identified. Furthermore, unique characteristics of the autoantibodies in IgA nephropathy have been uncovered. Many of these biochemical features are shared by patients with IgA nephropathy and Henoch-Schönlein purpura nephritis, suggesting that the two diseases may represent opposite ends of a spectrum of a disease process. Understanding the molecular mechanisms involved in the formation of pathogenic IgA1-containing immune complexes will enable the development of disease-specific therapies as well as diagnostic and prognostic biomarkers. Key Message IgA nephropathy is an autoimmune disease caused by the glomerular deposition of nephritogenic circulating immune complexes consisting of galactose-deficient IgA1 (autoantigen) bound by anti-glycan autoantibodies. A better understanding of the multi-step process of the pathogenesis of IgA nephropathy and the genetic and environmental contributing
Sidhom, Oussama; Laadhar, Lilia; Zitouni, Mondher; Ben Alaya, Nissaf; Rafrafi, Rym; Kallel-Sellami, Marayam; Lahmar, Houria; El Hechmi, Zouhair; Makni, Sondes
One hundred and three psychiatric inpatients (74 men) were assessed for a wide spectrum of autoantibodies including antinuclear, antismooth muscle, antimitochondrial, antiDNA, anti-phospholipid, anti-cardiolipin IgG and IgM, antikeratin, rheumatoid factor, antithyroperoxydase, antigliadin IgA and IgG, antitransgutaminase, and antiendomysium antibodies. Four groups of patients were considered separately, including 47 with schizophrenia, 23 with schizoaffective disorder, 16 with bipolar disorder and 17 patients with other different psychiatric diagnosis. Forty one healthy, age- and sex-matched blood donors were used as a control group. There were no significant difference in the prevalence of the different autoantibodies between patients (N = 103) and controls except for antigliadin IgG (30.1 vs 9.8 respectively, p = 0.01). Presence of autoantibodies was influenced by age but not by sex or treatment. As for diagnosis categories, patients with bipolar disorder presented significantly more autoantibodies than the three other categories and controls. These results point out a possible autoimmune activation in at least a subgroup of psychiatric patients especially amongst those suffering from bipolar disorder.
Grossmann, Kai; Röber, Nadja; Hiemann, Rico; Rödiger, Stefan; Schierack, Peter; Reinhold, Dirk; Laass, Martin W; Conrad, Karsten; Roggenbuck, Dirk
Celiac disease (CD) serology requires analysis of tissue transglutaminase type-2 (TG2autoAbs), deamidated gliadin (DGAbs), and as reference endomysial autoantibodies (EmA). Total IgA assessment helps to determine IgA-deficient CD patients. The novel multiplex indirect immunofluorescence (IIF) technique CytoBead was used to develop the first quantitative one-step serological CD assay comprising both simultaneous IgA autoAb and total IgA testing. CytoBead CeliAK detecting TG2autoAb, DGAb, EmA, and simultaneously total IgA uses fluorescent microparticles for antigen and antibody immobilization along with monkey-esophagus tissue sections on glass slides. The assay was interpreted visually by classical fluorescent microscopy and digital IIF using AKLIDES(®). Overall, 380 samples (155 CD patients, 5 with IgA deficiency, 68 with cystic fibrosis, 59 with eye disease, 93 blood donors) were run for performance analysis. Data were compared with classical IgA autoAb analysis by ELISA and IIF. Comparing CD-specific IgA autoAb testing by CytoBead with classical IIF and ELISA, very good agreements for EmA, TG2autoAb, and DGAb were determined (Cohen's κ = 0.98, 0.96, 0.85, respectively). The difference between multiplex and single testing revealed a significant difference for TG2autoAb testing only (McNemar, p = 0.0078). Four CD patients and 4 controls demonstrated TG2autoAb positivity by ELISA but were negative by CytoBead. Further, 140/155 (90.9 %) CD patients demonstrated TG2autoAb levels above ten times the upper normal and all five IgA-deficient samples IgA levels <0.2 g/L by CytoBead. The novel multiplex CytoBead CeliAK enables simultaneous CD-specific autoAb and IgA deficiency analyses comparable with classical testing by single-parameter assays. Thus, comprehensive CD serology by CytoBead can alleviate the workload in routine laboratories.
Burska, Agata N.; Hunt, Laura; Strollo, Rocky; Ryan, Brent J.; Vital, Ed; Nissim, Ahuva; Winyard, Paul G.; Emery, Paul; Ponchel, Frederique
Autoantibodies have been associated with human pathologies for a long time, particularly with autoimmune diseases (AIDs). Rheumatoid factor (RF) is known since the late 1930s to be associated with rheumatoid arthritis (RA). The discovery of anticitrullinated protein antibodies in the last century has changed this and other posttranslational modifications (PTM) relevant to RA have since been described. Such PTM introduce neoepitopes in proteins that can generate novel autoantibody specificities. The recent recognition of these novel specificities in RA provides a unique opportunity to understand human B-cell development in vivo. In this paper, we will review the three of the main classes of PTMs already associated with RA: citrullination, carbamylation, and oxidation. With the advancement of research methodologies it should be expected that other autoantibodies against PTM proteins could be discovered in patients with autoimmune diseases. Many of such autoantibodies may provide significant biomarker potential. PMID:24782594
DNA-like class R inhibitory oligonucleotides (INH-ODNs) preferentially block autoantigen-induced B-cell and dendritic cell activation in vitro and autoantibody production in lupus-prone MRL-Faslpr/lpr mice in vivo
Lenert, Petar; Yasuda, Kei; Busconi, Liliana; Nelson, Patrice; Fleenor, Courtney; Ratnabalasuriar, Radhika S; Nagy, Peter L; Ashman, Robert F; Rifkin, Ian R; Marshak-Rothstein, Ann
Introduction B cells have many different roles in systemic lupus erythematosus (SLE), ranging from autoantigen recognition and processing to effector functions (for example, autoantibody and cytokine secretion). Recent studies have shown that intracellular nucleic acid-sensing receptors, Toll-like receptor (TLR) 7 and TLR9, play an important role in the pathogenesis of SLE. Dual engagement of rheumatoid factor-specific AM14 B cells through the B-cell receptor (BCR) and TLR7/9 results in marked proliferation of autoimmune B cells. Thus, strategies to preferentially block innate activation through TLRs in autoimmune B cells may be preferred over non-selective B-cell depletion. Methods We have developed a new generation of DNA-like compounds named class R inhibitory oligonucleotides (INH-ODNs). We tested their effectiveness in autoimmune B cells and interferon-alpha-producing dendritic cells in vitro and in lupus-prone MRL-Faslpr/lpr mice in vivo. Results Class R INH-ODNs have 10- to 30-fold higher inhibitory potency when autoreactive B cells are synergistically activated through the BCR and associated TLR7 or 9 than when stimulation occurs via non-BCR-engaged TLR7/9. Inhibition of TLR9 requires the presence of both CCT and GGG triplets in an INH-ODN, whereas the inhibition of the TLR7 pathway appears to be sequence-independent but dependent on the phosphorothioate backbone. This difference was also observed in the MRL-Faslpr/lpr mice in vivo, where the prototypic class R INH-ODN was more effective in curtailing abnormal autoantibody secretion and prolonging survival. Conclusions The increased potency of class R INH-ODNs for autoreactive B cells and dendritic cells may be beneficial for lupus patients by providing pathway-specific inhibition yet allowing them to generate protective immune response when needed. PMID:19476613
Thoree, V C; Golby, S J C; Boursier, L; Hackett, M; Dunn-Walters, D K; Sanderson, J D; Spencer, J
Background: Ulcerative colitis (UC) is a chronic inflammatory bowel disease in which the colonic mucosa is infiltrated with plasma cells producing IgG autoantibodies. It is not known whether this represents a local mucosal response which has switched to IgG or a peripheral response which may have been initiated by peripheral antigen which homed to the colonic mucosa. The clonal distribution of IgG secreting cells and isotype switched variants in UC is not known. Aims: To investigate the clonal distribution of mucosal IgG in UC and to search for related IgG and IgA secreting cells in normal and diseased mucosa and blood in UC. To investigate characteristics which may discriminate between the mucosal and peripheral repertoire in the normal mucosa and in UC. Patients: Blood and normal and diseased mucosa from two patients with UC were studied. Methods: Immunoglobulin gene analysis and clone specific polymerase chain reaction were used to study the clonal distribution and characteristics of IgG and related IgA in the mucosa and blood of patients with UC. Results: The IgG response in the mucosa of UC patients included widespread clones of cells that were present in both the diseased mucosa and blood but that were scarce in normal mucosa. Clonally related IgA class switch variants, all IgA1, were detected but also only in the diseased mucosa and blood. This suggests that these clones home preferentially to the diseased mucosa. We showed that JH1 usage was characteristic of the peripheral repertoire, and that examples of JH1 usage were observed in mucosal IgG in UC. Conclusions: Overall, these data are consistent with a model of UC in which a peripheral response is expressed and expanded in the colonic mucosa. PMID:12077090
IgA nephritis (IgAN) is an autoimmune disease characterized by deposits of IgA in the glomerular mesangium. Clinically, the disease may be punctuated by episodes of macroscopic haematuria often associated with pharingotonsillitis or may be oligosyntomatic with microscopic haematuria and mild proteinuria. The natural course of IgAN may be indolent and benign; however, some 30-50% of patients may progress to end-stage renal disease when follow-up is extended to ≥20 years. In patients with IgAN, circulating IgA1 molecules have an aberrant structure of O-glycans in the hinge region, which is characterized by abbreviated glycans composed of N-acetylgalactosamine, with or without sialic acid. These aberrant IgA1 trigger the production of autoantibodies, with formation of immune complexes that deposit in the mesangium causing inflammation and production of extracellular matrix. A number of experimental and clinical data outlined a possible pathogenetic role of tonsillitis. As a consequence, tonsillectomy has been frequently performed in Japan. Observational studies, made in patients with normal renal function and mild proteinuria, reported that tonsillectomy could reduce the episodes of macrohaematuria as well as the entity of microhaematuria and proteinuria. However, the available studies had short-term follow-up and could not asses the role of tonsillectomy in protecting from renal function deterioration. In a longitudinal retrospective study, Isseki et al. compared the outcome of tonsillectomized patients with IgAN with that of IgAN patients who did not receive tonsillectomy. Tonsillectomized patients had a higher number of remissions and a better slope of glomerular filtration rate in comparison with controls. These data are interesting and suggest that tonsillectomy may prevent renal dysfunction in patients with IgAN and normal renal function. However, the retrospective nature of the study and the presence of some confounding factors require further investigations
Towmey, J. J.
Some immune response are effected through immunoglobulins (Ig), of which five classes have been recognized, namely, IgA, IgD, IgE, IgG, and IgM. Auto-antibodies associated with rheumatoid arthritis, termed rheumatoid factors (RF) react with antigenic determinants on IgG heavy chains. RF has predominant but not complete IgM specificity. This auto-antibody response was not detected in treated patients with primary brain tumors (where tissue is sequestered from the immune system by an intact bloodbrain barrier) or with multiple myeloma where humoral immunity is usually impaired. In addition, the prevalence of RF is not increased with solid tumors prior to initiation of chemotherapy or radiotherapy. It is proposed that RF is related to prior chemotherapy or radiotherapy of tumors anatomically accessible to immunologic tissues capable of antibody responses. A primary IgG response occurs, antigen-antibody complexes form, complexed IgG becomes immunologic, and an RF response results.
IgA nephropathy is glomerular disease first described in 1968 by Berger, named after him Morbus Berger. The disease is characterized by the presence of IgA dominant or codominant immunoglobulin deposits in glomerular mesangium which can be demonstrated by immunofluorescence. Clinical manifestations of IgA nephropathy in the majority of cases is hematuria which can be macro or microscopic, isolated or combined with proteinuria which can be of nephrotic range. In some cases nephrotic syndrome can be the first clinical presentation. In 10% renal insufficiency can be present at the onset of the disease. By light microscopy IgA can manifest any of the histologic phenotypes of immune complex mediated proliferative glomerulonephritis. According to light microscopy findings a classification system have been used to categorize the histologic patterns of IgA nephropathy. Glomerular changes in IgA nephropathy are proliferative and can be focal or diffuse accompanied by crescentic formation in many cases. Immune deposits seen by electron microscopy appear as electron dense deposits most numerous in mesangium.
Villalta, Danilo; Crovatto, Marina; Stella, Sergio; Tonutti, Elio; Tozzoli, Renato; Bizzaro, Nicola
Conflicting results were obtained in the assay of anti-transglutaminase (anti-tTG) autoantibodies in patients with chronic liver disease. In order to establish whether this was attributable to methodological differences, anti-tTG antibodies were assayed in a large number of patients suffering from liver cirrhosis (LC). 54 patients with LC and 29 patients suffering from celiac disease (CD), used as controls, were tested for IgA and IgG anti-tTG with 11 different commercial methods. In the patients with LC, positivity ranged from 0% to 33.3% for IgA anti-tTG and from 0% to 11.1% for anti-tTG of the IgG class. The largest number of false positives was found with methods that used tTG in association with gliadin peptides as antigen substrate. A significant association was found between IgA anti-tTG antibodies and serum immunoglobulin concentration. The results of the various methods of assaying anti-tTG antibodies in patients with LC are highly variable, and the positives found are generally false positives, partly due to the high immunoglobulin concentration.
Alhamid, Naji; Alterky, Hani; Almouslem, Amanda; Al-Rayess, Heba; Othman, Mohammad Imad
Donor specific antibodies (DSA) play a significant role in graft rejection. Many laboratory methods, varied in sensitivity and specificity, are used to detect them. We report a case of a 38-year-old man presented with end stage renal disease considered for kidney transplantation. He had no history of blood transfusions nor transplantation procedures. Dilemma rose when he got multiple positive crossmatches with matching donors and a positive autologous crossmatch due to IgG anti HLA auto-antibodies, which are at the same time against matched donors. Since positive crossmatch is a contraindication for transplant, we couldn't perform transplant from any matched donor. Therefore, we considered a total mismatched donor then transplantation was performed. Observation after surgery showed normalization of creatinine, blood pressure and a good function of the planted allograft for two years of follow up. Copyright © 2014 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.
Willis, Van C.; Demoruelle, M. Kristen; Derber, Lezlie A.; Chartier-Logan, Catherine J.; Parish, Mark C.; Pedraza, Isabel F.; Weisman, Michael H.; Norris, Jill M.; Holers, V. Michael; Deane, Kevin D.
Objective To evaluate the generation of rheumatoid arthritis (RA)–related autoantibodies in the lung. Methods Simultaneous collection of serum and induced sputum was performed in 21 healthy controls, 49 at-risk subjects without inflammatory arthritis but at risk of RA due to family history or seropositivity for anti–citrullinated protein antibodies, and 14 subjects with early RA. Samples were tested for anti–cyclic citrullinated peptide 2 (anti-CCP2), anti-CCP3, anti-CCP3.1, rheumatoid factor isotypes IgM, IgG, and IgA, and total IgM, IgG, and IgA. Results One or more autoantibodies were present in sputum of 39% of at-risk seronegative subjects, 65% of at-risk seropositive subjects, and 86% of subjects with early RA. In at-risk seronegative subjects, the rate of anti-CCP3.1 positivity and the median number of autoantibodies were elevated in sputum versus serum. In subjects with early RA, the rate of positivity for several individual autoantibodies and the median number of autoantibodies were higher in serum than in sputum. Results in at-risk seropositive subjects were intermediate between these groups. In at-risk subjects with autoantibody positivity in sputum, the ratios of autoantibody to total Ig were higher in sputum than in serum, suggesting that these autoantibodies are generated or sequestered in the lung. Conclusion RA-related autoantibodies are detectable in sputum in subjects at risk of RA and in subjects with early RA. In a subset of at-risk subjects, the presence of sputum autoantibodies in the absence of seropositivity, and the increased autoantibody-to–total Ig ratios in sputum, suggest that the lung may be a site of autoantibody generation in the early development of RA. These findings suggest an important role of the lung in the pathogenesis of RA. PMID:23817979
Mokhtari, Fatemeh; Panjehpour, Tayebeh; Naeini, Farahnaz Fatemi; Hosseini, Sayed Mohsen; Nilforoushzadeh, Mohammad Ali; Matin, Marzieh
Background: Alopecia areata (AA) is a noncicatricial (nonscarring) alopecia. The association between AA and celiac disease (CD) is debatable. Several studies declare the relationship between AA and CD as measurement of celiac autoantibodies (anti-gliadin IgA and anti-gliadin IgG), but a few studies consider anti-tissue transglutaminase IgA. The aim of this study was to evaluate the frequency distribution of celiac autoantibodies (all of them) in patients with AA compared with controls. Methods: This study is a case–control study. Thirty-five patients entered in each group. Anti-gliadin IgA, anti-gliadin IgG, and anti-tissue transglutaminase IgA were tested in all patients. Samples were examined in ELISA method with binding site's kits, and the result was reported as positive/negative. Finally, the frequency distribution of autoantibodies was examined. Results: The age average did not show a significant difference between two groups (P = 0.62). In addition, there was no significant difference between the two groups based on gender (P = 0.15). The prevalence of antibody in case and control groups was 2.85% and 0%, respectively. There was no significant difference between the two groups (P = 0.31). Conclusions: There may be a relationship between CD and AA, but the absence of statistical association between AA and CD does not mean that there is no relationship between gluten and AA in certain patients. Thus, we have shown here that the biological tests to search for CD do not bring information and proof enough, and it is why we recommend another approach to disclose gluten intolerance in AA patients. PMID:27833723
Holt, P D; Tandy, N P; Anstee, D J
Altogether 29 745 English blood donors were screened for IgA deficiency by double diffusion analysis; 57 had apparent absence of IgA, a frequency of 1:522. Further examination by the more sensitive haemagglutination inhibition assay revealed 34 samples having no detectable IgA, a frequency of 1:875. All donors negative by double diffusion analysis were tested for the presence of antibodies to IgA. Six class specific anti IgA antibodies and four anti IgA antibodies of limited specificity were detected. Three of these had the specificity anti alpha2 and one anti A2m(2). The 34 IgA deficient donors detected provide a source of IgA deficient blood for transfusion to patients with anti IgA antibodies. PMID:304071
Rodríguez, Libia M; París, Sara C; Arbeláez, Mario; Cotes, José M; Süsal, Caner; Torres, Yolanda; García, Luís F
In the present study, we investigated whether pretransplantation HLA class I and class II antibodies and pretransplantation levels of soluble CD30 (sCD30) and IgA anti-Fab autoantibodies are predictive of kidney allograft survival. Pretransplantation sera of 504 deceased-donor kidney recipients were tested for IgG HLA class I and class II antibodies, sCD30, and IgA anti-Fab levels using the CTS 4 ELISA kit. Kidney graft survival was estimated by Kaplan-Meier method and multivariate Cox regression. Regardless of the presence of HLA class II antibodies, recipients with high HLA class I reactivity had lower 1-year graft survival than recipients with low reactivity (p < 0.01). Recipients with high sCD30 had lower 5-year graft survival rate than those with low sCD30 (p < 0.01). The sCD30 effect was observed in presensitized and nonsensitized recipients, demonstrated a synergistic effect with HLA class I antibodies (p < 0.001), and appeared to be neutralized in recipients with no HLA class II mismatches. IgA anti-Fab did not influence kidney graft survival. Our results indicate that high pretransplantation sCD30 levels and HLA class I positivity increase the risk of kidney graft loss regardless of other factors. Consequently, such determinations should be routinely performed to estimate recipients' risks of graft rejection before transplantation.
Richaud-Patin, Y; Villa, A R
Immunological failure may be the cause of predisposition to certain infections, neoplasms, and vascular diseases in adulthood. Mortality risks through life may reflect an undetermined number of causes. This study describes the prevalence of positivity of autoantibodies through life, along with general and specific mortality causes in three countries with different socioeconomic development (Guatemala, Mexico and the United States). Prevalence of autoantibodies by age was obtained from previous reports. In spite of having involved different ethnic groups, the observed trends in prevalence of autoantibodies, as well as mortality through life, showed a similar behavior. Thus, both the increase in autoantibody production and death risk as age rises, may share physiopathological phenomena related to the ageing process.
Beltrão, Marília; Bodas, Abilia; Azevedo, Fernando; Nunes, Amadeu; Santos, Carlos; Delgado, Luís
The incidence of inflammatory bowel disease (IBD) has been increasing worldwide, and despite the advances regarding their pathogenesis and therapeutics, the differential diagnosis between Crohn's Disease (CD) and Ulcerative Colitis (UC) is mainly based on clinically invasive tests. Recent studies have identified new serological markers with a potential value for the diagnosis of these pathologies, in particular the anti-Saccharomyces cerevisiae antibodies (ASCA) and anti-neutrophil cytoplasmic antibodies (ANCA). Also of note are the anti-goblet cells antibodies (anti-CCI) and the anti-pancreatic exocrine autoantibodies that react with the pancreatic acinus (anti-AP). We assessed these new serological markers and compared the efficiency between immune enzymatic (ELISA) and indirect immunofluorescence tests in the identification of ASCA of IgG or IgA class. We studied a set of 81 serum samples (with an initial diagnosis of IBD) and 33 control samples from healthy blood donors. The laboratory tests were correlated with the diagnosis of each patient, established in the Gastroenterology outpatient unit based on conventional methods. The agreement between the two laboratory methods employed in the identification of the ASCA was excellent (k = 0.63) for the IgG antibodies and good (k = 0.56) for the IgA antibodies. We found a weak agreement (k = 0.137) between ELISA (MPO and PR3 purified antigens) and the IFA test for ANCA. Regarding the serologic markers ANCA, anti-AP and anti-CCI, only the later showed no differences in the distribution of positive results between the studied groups. Positive ASCA IgG and IgA were significantly associated with diagnosis of DC, with both laboratorial methods tested. The identification of ANCA with the available solidphase tests does not seem appropriate for the screening of the autoantibodies with the atypical p-ANCA pattern of IBD. The combination between anti-AP and ASCA antibodies seems a good option for the laboratorial diagnosis of
Rauen, Thomas; Floege, Jürgen
Immunoglobulin A nephropathy (IgAN) is the most frequently occurring primary glomerulonephritis in Caucasian and Asian populations. Nonetheless, therapeutic recommendations are based on weak evidence, large controlled trials are scarce and, in particular, the additional value of immunosuppression beyond comprehensive supportive measures is not well-established. The use of immunosuppressants is supported by experimental insights into IgAN pathogenesis that suggest an autoimmune component in disease development. The so-called "multi-hit" theory comprises multiple steps, starting with defective glycosylation of IgA subclass IgA1 that results in overproduction of galactose-deficient IgA1 (Gd-IgA1), occurrence of anti-Gd-IgA1 autoantibodies, and mesangial deposition of nephritogenic immune complexes. This eventually results in an increased mesangial cell proliferation, inflammatory responses, and complement activation. Recent genome-wide association studies have identified several susceptibility genes, many of which support the "multi-hit" concept. In light of these discoveries, it is astonishing that the vast majority of adult IgAN patients obviously do not need and/or benefit from immunosuppressive therapies in the first place. In fact, a number of supportive measures are highly effective in reducing the risk for disease progression in many patients. These measures need to be optimized before immunosuppression should be considered at all. In this review we focus on the underlying pathogenetic cornerstones and the central question of whether systemic inflammation in adult IgAN patients should be treated. Treatment options in children with IgAN are also discussed.
Papista, Christina; Lechner, Sebastian; Ben Mkaddem, Sanae; LeStang, Marie-Bénédicte; Abbad, Lilia; Bex-Coudrat, Julie; Pillebout, Evangéline; Chemouny, Jonathan M; Jablonski, Mathieu; Flamant, Martin; Daugas, Eric; Vrtovsnik, François; Yiangou, Minas; Berthelot, Laureline; Monteiro, Renato C
IgA1 complexes containing deglycosylated IgA1, IgG autoantibodies, and a soluble form of the IgA receptor (sCD89), are hallmarks of IgA nephropathy (IgAN). Food antigens, notably gluten, are associated with increased mucosal response and IgAN onset, but their implication in the pathology remains unknown. Here, an IgAN mouse model expressing human IgA1 and CD89 was used to examine the role of gluten in IgAN. Mice were given a gluten-free diet for three generations to produce gluten sensitivity, and then challenged for 30 days with a gluten diet. A gluten-free diet resulted in a decrease of mesangial IgA1 deposits, transferrin 1 receptor, and transglutaminase 2 expression, as well as hematuria. Mice on a gluten-free diet lacked IgA1-sCD89 complexes in serum and kidney eluates. Disease severity depended on gluten and CD89, as shown by reappearance of IgAN features in mice on a gluten diet and by direct binding of the gluten-subcomponent gliadin to sCD89. A gluten diet exacerbated intestinal IgA1 secretion, inflammation, and villous atrophy, and increased serum IgA1 anti-gliadin antibodies, which correlated with proteinuria in mice and patients. Moreover, early treatment of humanized mice with a gluten-free diet prevented mesangial IgA1 deposits and hematuria. Thus, gliadin-CD89 interaction may aggravate IgAN development through induction of IgA1-sCD89 complex formation and a mucosal immune response. Hence, early-stage treatment with a gluten-free diet could be beneficial to prevent disease.
Autoantibodies are the serological hallmark of autoimmune disease. Though their pathogenic role is debatable, they play an important role in the management of a patient with rheumatic disease. However, due to their presence in the general population as well as in multiple autoimmune diseases, the presence of an autoantibody alone does not make a diagnosis; the result has to be interpreted along with clinical findings. Similarly, the absence of autoantibody does not exclude a disease. The common autoantibodies used in clinical practice include rheumatoid factor, anti-CCP antibodies, antinuclear antibodies (ANAs), anti-neutrophil cytoplasmic antibodies (ANCA) and anti-phospholipid antibodies. Once an autoantibody to a broad antigen is detected in a patient, sub-specificity analysis can improve the utility of the antibody. Autoantibodies are detected in the serum using different assays and results of which can vary; thus, it is important for a clinician to know the method used, its sensitivity and specificity to help in the proper interpretation of the laboratory results. This review will address these issues.
Thyroid peroxidase (TPO) is a member of the thyroid autoantigens. Anti-thyroid autoantibodies, anti-TPO,-thyroglobulin and -TSH receptor autoantibodies, are important in diagnosing autoimmune thyroid diseases and for judging treatment efficacy. To diagnose chronic thyroiditis, anti-TPO autoantibody detection is the most sensitive among the three anti-thyroid autoantibodies. Eighty-five to ninety percent of patients with chronic thyroiditis have anti-TPO autoantibodies. Using recombinant human TPO protein, a kit measuring anti-TPO antibodies specifically have been developed. The developmental process and specificity of the kit are discussed. Compared with the microsome test, the most greatest advantage of the anti-TPO EIA kit can specifically measure anti-TPO antibodies. Structure of anti-TPO antibody immunoglobulin, which has been demonstrated over the last several years using the phage display method, is also discussed. The most prominent feature is that VL is believed to be important in determining anti-TPO antibody specificity in contrast to that of other autoantibodies, although VL itself does not have TPO-binding activity.
Brandsma, Corry-Anke; Kerstjens, Huib A M; van Geffen, Wouter H; Geerlings, Marie; Postma, Dirkje S; Hylkema, Machteld N; Timens, Wim
Several studies have demonstrated the presence of B-cell follicles and autoantibodies in chronic obstructive pulmonary disease (COPD). It is unclear against which antigens this B-cell response is directed and whether it contributes to development or worsening of disease. We assessed different B-cell subsets in blood and lung tissue from COPD patients and controls, and compared differences in B-cell responsiveness to stimulation with lung-specific antigens. Active smoking induced an adaptive immune response with relatively high levels of (class-switched) memory B-cells in blood and immunoglobulin (Ig)G memory B-cells in the lung. COPD smokers showed more switching to IgG, whereas healthy smokers switched more to IgA. COPD patients had higher levels of memory B-cells in the lung and stimulation with lung-specific antigens induced higher numbers of anti-decorin antibody-producing cells in COPD patients compared with healthy controls. Differential switching to IgG and IgA indicates that the adaptive immune response to smoke differs between COPD patients and healthy controls. A higher level of memory B-cells in the lungs of COPD patients may reflect an antigen-specific immune response, which could be directed against decorin, as suggested by the induction of anti-decorin antibody-producing cells in response to antigen-specific stimulation in COPD patients.
Budding, K; van de Graaf, E A; Hoefnagel, T; Hack, C E; Otten, H G
Bactericidal/permeability increasing protein fold containing family A (BPIFA) 1, is a secreted protein of the upper airways that shares structural homology with BPI and exhibits comparable antimicrobial capacities. We hypothesized that CF patients have circulating IgG or IgA anti-BPIFA1 autoantibodies, similarly as reported for BPI autoantibodies. We analyzed pre- and post-transplantation sera from 67 endstage lung disease patients who underwent lung transplantation (LTx) because of COPD (n=27), CF (n=25), and ILD (n=15). Anti-BPIFA1 (48%) and anti-BPI (92%) were elevated in CF patients compared to healthy controls, with anti-BPIFA1 IgG isotype being most prevalent, whereas anti-BPI is of the IgA isotype. Levels of anti-BPI autoantibodies significantly declined post-LTx, whereas anti-BPIFA1 did not. No relation was found between autoantibodies against BPIFA1 and BPI. Our results indicate that BPIFA1 is a novel target for autoantibodies in CF. The function of these autoantibodies needed to be investigated in future studies. © 2013.
Knoppova, Barbora; Reily, Colin; Maillard, Nicolas; Rizk, Dana V.; Moldoveanu, Zina; Mestecky, Jiri; Raska, Milan; Renfrow, Matthew B.; Julian, Bruce A.; Novak, Jan
IgA nephropathy (IgAN) is the most common primary glomerulonephritis, frequently leading to end-stage renal disease, as there is no disease-specific therapy. IgAN is diagnosed from pathological assessment of a renal biopsy specimen based on predominant or codominant IgA-containing immunodeposits, usually with complement C3 co-deposits and with variable presence of IgG and/or IgM. The IgA in these renal deposits is galactose-deficient IgA1, with less than a full complement of galactose residues on the O-glycans in the hinge region of the heavy chains. Research from the past decade led to the definition of IgAN as an autoimmune disease with a multi-hit pathogenetic process with contributing genetic and environmental components. In this process, circulating galactose-deficient IgA1 (autoantigen) is bound by antiglycan IgG or IgA (autoantibodies) to form immune complexes. Some of these circulating complexes deposit in glomeruli, and thereby activate mesangial cells and induce renal injury through cellular proliferation and overproduction of extracellular matrix components and cytokines/chemokines. Glycosylation pathways associated with production of the autoantigen and the unique characteristics of the corresponding autoantibodies in patients with IgAN have been uncovered. Complement likely plays a significant role in the formation and the nephritogenic activities of these complexes. Complement activation is mediated through the alternative and lectin pathways and probably occurs systemically on IgA1-containing circulating immune complexes as well as locally in glomeruli. Incidence of IgAN varies greatly by geographical location; the disease is rare in central Africa but accounts for up to 40% of native-kidney biopsies in eastern Asia. Some of this variation may be explained by genetically determined influences on the pathogenesis of the disease. Genome-wide association studies to date have identified several loci associated with IgAN. Some of these loci are associated
Gupta, Sarthak; Tatouli, Ioanna P; Rosen, Lindsey B; Hasni, Sarfaraz; Alevizos, Ilias; Manna, Zerai G; Rivera, Juan; Jiang, Chao; Siegel, Richard M; Holland, Steven M; Moutsopoulos, Haralampos M; Browne, Sarah K
of disease in SLE, SS, and RA. Anti-interferon autoantibodies are overrepresented in patients with SLE and those with SS, and fall into distinct functional classes, with only a subset of anti-type I interferon antibodies exhibiting neutralizing activity. Anti-interferon-γ autoantibodies are correlated with increased disease activity and interferon-related gene expression, suggesting that such autoantibodies may contribute to the pathogenesis of SLE. © 2016, American College of Rheumatology.
Fujiwara, Saeko; Akahoshi, Masazumi; Kodama, Kazunori; Shimaoka, Katsutaro; Akiyama, Mitoshi; Carter, R.L.; Yamakido, Michio
The purpose of this study was to determine if exposure to atomic bomb radiation affects immune responsiveness, such as the occurrence of autoantibodies and levels of immunoglobulins. Rheumatoid factor, antinuclear antibody, antithyroglobulin antibody, anti-thyroid-microsomal antibody and immunoglobulin levels (IgG, IgM, IgA and IgE) were measured among 2,061 individuals exposed to atomic bomb radiation in Hiroshima and Nagasaki whose estimated doses ranged from 0 to 5.6 Gy. The prevalence and titers of rheumatoid factor were found to be increased in the individuals exposed to higher radiation doses. The IgA level in females and the IgM level in both sexes increased as radiation dose increased, although the effects of radiation exposure were not large. No effect of radiation was found on the prevalence of antinuclear antibody, antithyroglobulin antibody and anti-thyroid-microsomal antibody or on the levels of IgG and IgE. 32 refs., 2 figs., 3 tabs.
Geller, Shamir; Gat, Andrea; Harel, Avikam; Mashiah, Jacob; Zeeli, Tal; Eming, Rüdiger; Ishii, Norito; Hertl, Michael; Hashimoto, Takashi; Sprecher, Eli
Pemphigus refers to a group of potentially fatal blistering skin diseases that are often due to the deleterious effects of autoantibodies directed against desmosomal antigens. Although desmogleins have been mainly implicated as autoantigens in pemphigus, a steadily growing body of evidence suggests that other desmosomal proteins may be causally involved as well. Antibodies directed against desmocollin-3 have been shown to play a direct role in the pathogenesis of several types of pemphigus. Here we describe the case of a child with localized pemphigus foliaceus and immunoglobulin G (IgG) reactivity exclusively directed to desmocollins. The present report suggests that autoantibodies against nondesmoglein antigens may play a role in the pathogenesis of superficial pemphigus, in addition to pemphigus vulgaris, paraneoplastic pemphigus, and IgA pemphigus.
Immunoglobulin A (IgA) nephropathy is the most common glomerulonephritis worldwide. For example, in Japan, full-blown IgA nephropathy has been detected in ~1.5% of all allograft kidneys at the time of transplant. Genetic and environmental modifiers, as well as generic progression factors (eg, hypertension), must have a major role in determining who will become clinically overt and who will experience progression. In patients with clinically overt IgA nephropathy and/or progressive disease, it now is relatively well established that the pathogenesis involves 6 major steps: (1) Increased occurrence of IgA1 with poor galactosylation in the circulation. This might relate to the migration of mucosal B cells to bone marrow, where they produce "correct" poorly galactosylated IgA. Modulation of mucosal immunity may offer new therapeutic options. (2) Generation of IgG antibodies against poorly galactosylated IgA1. This could lay the foundation for immunosuppression, whereas detection of such IgG autoantibodies may accommodate the noninvasive monitoring of IgA nephropathy. (3) Mesangial deposition and/or formation of IgG-IgA1 or IgA1-IgA1 complexes. (4) Activation of mesangial IgA receptors and/or complement; both lend themselves to therapeutic interference. (5) Mesangial cell damage and activation of secondary pathways, such as overproduction of platelet-derived growth factor, which can be targeted specifically. (6) Activation of pathomechanisms that are not specific for IgA nephropathy and that drive glomerulosclerosis and tubulointerstitial fibrosis. Although at present our therapeutic armamentarium is still limited largely to supportive care and immunosuppression in some instances, these new insights can be expected to yield novel, perhaps individualized, therapeutic options in primary and recurrent IgA nephropathy. Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Cao, Anthony T.; Yao, Suxia; Gong, Bin; Nurieva, Roza I.; Elson, Charles O.; Cong, Yingzi
Commensal microbiota-specific Th17 cells are enriched in the intestines, which can convert into Tfh in Peyer’s patches, and are crucial for production of intestinal IgA against microbiota, however, the role of Th17 and Tfh cytokines in regulating the mucosal IgA response to enteric microbiota is still not completely known. In this study, we found that intestinal IgA was impaired in mice deficient in IL-17 or IL-21 signaling. IL-21, but not IL-17, is able to augment B cell differentiation to IgA+ cells as mediated by TGFβ1, and accelerate IgA class switch recombination (CSR). IL-21 and retinoic acid (RA) induce IgA+ B cell development and IgA production, and drives autocrine TGFβ1 production to initiate IgA CSR. Repletion of T cell-deficient TCRβxδ−/− mice with Th17 cells specific for commensal bacterial antigen, increased levels of IgA+ B cells and IgA production in the intestine, which was blocked by neutralizing IL-21. Thus, IL-21 functions to strongly augment IgA production under intestinal environment. Furthermore, IL-21 promotes intestinal B cell homing through α4β7 expression, alone or with TGFβ and RA. Together, IL-21 from microbiota-specific Th17 and/or Tfh cells contributes to robust intestinal IgA levels by enhancing IgA+ CSR, IgA production, and B cell trafficking into the intestine. PMID:25586558
Kihara, Masao; Ito, Kiyoaki; Nakata, Junichiro; Otani, Masako; Tran, Ngoc Lan; Morito, Naoki; Takahashi, Satoru; Wada, Yoshinao
Deficient glycosylation of O-linked glycans in the IgA1 hinge region is associated with IgA nephropathy in humans, but the pathogenic contribution of the underlying structural aberrations remains incompletely understood. We previously showed that mice implanted with cells secreting the class-switch variant 6-19 IgA anti-IgG2a rheumatoid factor, but not 46-42 IgA anti-IgG2a rheumatoid factor, develop glomerular lesions resembling IgA nephropathy. Because the levels of O-linked glycosylation in the hinge region and the structures of N-linked glycans in the CH1 domain differ in 6-19 IgA and 46-42 IgA, we determined the respective contributions of O- and N-linked glycans to the nephritogenic potential of the 6-19 IgA rheumatoid factor in mice. Wild-type 6-19 IgA secreted by implanted cells induced significant formation of glomerular lesions, whereas poorly O-glycosylated 6-19 IgA glycovariants or a 6-19 IgA hinge mutant lacking O-linked glycans did not. However, we observed no apparent heterogeneity in the structure of N-linked glycans attached to three different sites of the Fc regions of nephritogenic and non-nephritogenic 6-19 IgAs. Collectively, our data suggest a critical role of O-linked glycans attached to the hinge region in the development of IgA nephropathy–like GN induced by 6-19 IgA rheumatoid factor in mice. PMID:24511137
Cao, A T; Yao, S; Gong, B; Nurieva, R I; Elson, C O; Cong, Y
Commensal microbiota-specific T helper type 17 (Th17) cells are enriched in the intestines, which can convert into T follicular helper (Tfh) in Peyer's patches, and are crucial for production of intestinal immunoglobulin A (IgA) against microbiota; however, the role of Th17 and Tfh cytokines in regulating the mucosal IgA response to enteric microbiota is still not completely known. In this study, we found that intestinal IgA was impaired in mice deficient in interleukin (IL)-17 or IL-21 signaling. IL-21, but not IL-17, is able to augment B-cell differentiation to IgA(+) cells as mediated by transforming growth factor β1 (TGFβ1) and accelerate IgA class switch recombination (CSR). IL-21 and retinoic acid (RA) induce IgA(+) B-cell development and IgA production and drives autocrine TGFβ1 production to initiate IgA CSR. Repletion of T-cell-deficient TCRβxδ(-/-) mice with Th17 cells specific for commensal bacterial antigen increased the levels of IgA(+) B cells and IgA production in the intestine, which was blocked by neutralizing IL-21. Thus IL-21 functions to strongly augment IgA production under intestinal environment. Furthermore, IL-21 promotes intestinal B-cell homing through α4β7 expression, alone or with TGFβ and RA. Together, IL-21 from microbiota-specific Th17 and/or Tfh cells contributes to robust intestinal IgA levels by enhancing IgA(+) CSR, IgA production and B-cell trafficking into the intestine.
Asherson, G. L.; Dumonde, D. C.
The sera of rabbits injected with rat liver, kidney, heart, muscle, spleen and brain in Freund's complete adjuvant fixed complement with rabbit tissue. This complement-fixing activity was attributed to autoantibodies which were able to fix complement in vitro with the tissue of the rabbit in which they occurred. Absorption, gel diffusion and antibody and antigen titrations indicated that some of the anti-liver, anti-kidney, anti-heart, anti-muscle and anti-brain sera contained organ-specific autoantibody. The sera also contained autoantibody reacting with widely distributed antigen(s), which was relatively labile at 65°. The anti-kidney and anti-brain sera reacted with distinct antigens which were extracted from rabbit kidney and brain with a mixture of chloroform and methanol. The natural autoantibody of Kidd and Friedewald was usually labile at 65° and behaved like a macroglobulin on sucrose gradient centrifugation. Sera taken 1 week after immunization with rat tissue contained heat-labile macroglobulin antibody. However, sera taken 1 month after immunization also contained small molecular weight antibody which was stable at 65°. PMID:13965166
Zhu, Honglin; Luo, Hui; Yan, Mei; Zuo, Xiaoxia; Li, Quan-Zhen
Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by the production of autoantibodies to a broad range of self-antigens. Profiling the autoantibody repertoire using array-based technology has emerged as a powerful tool for the identification of biomarkers in SLE and other autoimmune diseases. Proteomic microarray has the capacity to hold large number of self-antigens on a solid surface and serve as a high-throughput screening method for the determination of autoantibody specificities. The autoantigen arrays carrying a wide variety of self-antigens, such as cell nuclear components (nucleic acids and associated proteins), cytoplasmic proteins, phospholipid proteins, cell matrix proteins, mucosal/secreted proteins, glomeruli, and other tissue-specific proteins, have been used for screening of autoantibody specificities associated with different manifestations of SLE. Arrays containing synthetic peptides and molecular modified proteins are also being utilized for identification of autoantibodies targeting to special antigenic epitopes. Different isotypes of autoantibodies, including IgG, IgM, IgA, and IgE, as well as other Ig subtypes, can be detected simultaneously with multi-color labeled secondary antibodies. Serum and plasma are the most common biologic materials for autoantibody detection, but other body fluids such as cerebrospinal fluid, synovial fluid, and saliva can also be a source of autoantibody detection. Proteomic microarray as a multiplexed high-throughput screening platform is playing an increasingly-important role in autoantibody diagnostics. In this article, we highlight the use of autoantigen microarrays for autoantibody exploration in SLE.
IgA nephropathy (IgAN) has variable clinical presentation and outcome. There is a need to identify children who have the potential to progress to end stage renal disease (ESRD). Biomarkers related to the pathogenetic process of IgAN can detect risk factors and identify targets for new therapies. Galactose-deficient IgA1 (Gd-IgA1) is a specific biomarker of IgAN and could be the first treatment target. In experimental mice, reduction of IgA1 deposits and hematuria was observed after treatment with a bacterial protease that selectively cleaves human IgA1. Glycan-targeted drugs that may act to neutralize Gd-IgA1 inhibit abnormal enzymatic glycosylation of IgA1 or deplete cells producing Gd-IgA1. The autoimmune response to Gd-IgA1 produces autoantibodies that are sensitive and specific biomarkers of IgAN development and progression and suggests the possible benefits of anti-B cell therapies directed against CD20, B-cell activating factor (BAFF), or B cell receptor, and also proteasome inhibitors. The activation of complement in IgAN offers new biomarkers and the rationale for using complement inhibitors, including eculizumab. Renal pathological features represent sensitive biomarkers of added value over clinical data and may drive steroid therapy in selected cases. Finally, the hypothesis of the involvement of intestinal mucosal immunity in the pathogenesis of IgAN suggests the possibility of avoiding the systemic effect of steroid. Enteric budesonide targeting Peyer's patches at the ileocecal junction is an interesting option that has provided some preliminary favorable results in IgAN. In conclusion, the identification of new biomarkers is a promising area for therapies targeting IgAN in patients at risk of progression.
Rodrigues, Jennifer C; Haas, Mark; Reich, Heather N
IgA nephropathy (IgAN) is a leading cause of CKD and renal failure. Recent international collaborative efforts have led to important discoveries that have improved our understanding of some of the key steps involved in the immunopathogenesis of IgAN. Furthermore, establishment of multicenter networks has contributed to rigorous design and execution of clinical trials that have provided important insights regarding immunotherapy in IgAN. In this article, we review emerging developments in clinical and translational IgAN research and describe how these novel findings will influence future strategies to improve the outcome of patients with IgAN.
Asherson, G. L.; Holborow, E. J.
Rabbits received two injections of dead bacteria in Freund's complete adjuvant. One month later the sera of the rabbits were examined for autoantibodies against gut by indirect immunofluorescence using the rabbit's own stomach, ileum and colon taken at post mortem. Autoantibodies against colon were found in three out of seven rabbits injected with one particular strain of Escherichia coli O64 and in a few animals injected with other E. coli, Salmonella arizona, Proteus mirabilis, Klebsiella pneumoniae and Streptococcus faecalis. The antigen, with which the autoantibodies reacted, behaved like mucus and was detected in the colon and sometimes in the ileum and the stomach. Three patterns of staining were observed: (a) staining of the superficial mucosa of the colon with sparing of the deep glands; (b) staining of scattered groups of glands in the deepest part of the colon with sparing of the superficial glands (this pattern of staining was associated with staining of the superficial mucosa of the body of the stomach); and (c) staining of both the superficial and deep glands of the colon. None of the sera tested reacted with the bronchial or salivary glands. Polysaccharide preparations of the colon, but not the stomach, inhibited the reaction of the autoantibodies with colon in the sera tested. The amount of antigen needed to inhibit the basal staining was much greater than that needed to inhibit the superficial staining. It was concluded that rabbits may produce autoantibodies to colon and in some cases to ileum and stomach following the injection of certain dead bacteria in Freund's complete adjuvant. ImagesFIGS. 1-2FIG. 3FIG. 4FIG. 5FIG. 6 PMID:4956607
Moro-Sibilot, Ludovic; This, Sebastien; Blanc, Pascal; Sanlaville, Amelien; Sisirak, Vanja; Bardel, Emilie; Boschetti, Gilles; Bendriss-Vermare, Nathalie; Defrance, Thierry; Dubois, Bertrand; Kaiserlian, Dominique
Intestinal DCs orchestrate gut immune homeostasis by dampening proinflammatory T-cell responses and inducing anti-inflammatory IgA responses. Although no specific DC subset has been strictly assigned so far to govern IgA response, some candidate subsets emerge. In particular, plasmacytoid DCs (pDCs), which notoriously promote anti-viral immunity and T-cell tolerance to innocuous antigens (Ags), contribute to IgA induction in response to intestinal viral infection and promote T-cell-independent IgA responses in vitro. Here, using two transgenic mouse models, we show that neither short-term nor long-term pDC depletion alters IgA class switch recombination in Peyer's patches and frequency of IgA plasma cells in intestinal mucosa at steady state, even in the absence of T-cell help. In addition, pDCs are dispensable for induction of intestinal IgA plasma cells in response to oral immunization with T-cell-dependent or T-cell-independent Ags, and are not required for proliferation and IgA switch of Ag-specific B cells in GALT. These results show that pDCs are dispensable for noninfectious IgA responses, and suggest that various DC subsets may play redundant roles in the control of intestinal IgA responses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Akhi, Ramin; Wang, Chunguang; Kyrklund, Mikael; Kummu, Outi; Turunen, Sini Pauliina; Hyvärinen, Kati; Kullaa, Arja; Salo, Tuula; Pussinen, Pirkko J; Hörkkö, Sohvi
Oxidized low-density lipoproteins (oxLDL) are formed as a result of lipid peroxidation and are highly immunogenic and proatherogenic. In this study, saliva antibodies binding to oxLDL, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) were characterized and their cross-reactivity was evaluated. Resting and stimulated saliva samples were collected from 36 healthy adults (mean age 26 years). Saliva IgA, IgG and IgM autoantibody levels to copper oxidized LDL (CuOx-LDL) and malondialdehyde acetaldehyde-modified LDL (MAA-LDL) were determined with chemiluminescence immunoassay. Saliva IgA and IgG antibodies binding to MAA-LDL and CuOx-LDL were detected in all samples and they were associated with the saliva levels of IgA and IgG to P. gingivalis and A. actinomycetemcomitans. Competitive immunoassay showed that saliva antibodies to MAA-LDL cross-reacted specifically with P. gingivalis. The autoantibody levels to oxLDL in saliva were not associated with the autoantibody levels to oxLDL in plasma or with saliva apolipoprotein B 100 levels. Saliva contains IgA and IgG binding to oxLDL, which showed cross-reactive properties with the periodontal pathogens Porphyromonas gingivalis (P.g). The data suggest that secretory IgA to P.g may participate in immune reactions involved in LDL oxidation through molecular mimicry. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
The B cell repertoire in patients with systemic autoimmune diseases: analysis of Epstein-Barr virus (EBV)-inducible circulating precursors that produce autoantibodies against nuclear ribonucleoprotein (nRNP).
Okawa-Takatsuji, M; Aotsuka, S; Uwatoko, S; Sumiya, M; Yokohari, R
Peripheral blood B cells from patients with systemic autoimmune disease and healthy volunteers were immortalized using EBV and the frequencies of B cell precursors that produced immunoglobulin class-specific antibodies against anti-nRNP, a specific marker for mixed connective tissue disease, were assessed using limiting dilution analysis. The frequencies of EBV-induced B cell precursors that produced IgG anti-nRNP were correlated closely with the serum titres of the corresponding autoantibodies, which indicates that B cell precursors that produced potentially pathogenic autoantibodies could be immortalized from the peripheral blood of the patients by EBV. In contrast, the frequency of EBV-induced B cell precursors that produced IgM anti-nRNP in patients with systemic autoimmune disease was comparable to that in healthy volunteers and greater than those that produced IgG and IgA anti-nRNP. Moreover, many of the clones that produced IgM antibodies against nRNP reacted with other autoantigens, such as double-stranded DNA, single-stranded DNA and rabbit IgG. These polyreactive IgM antibodies are believed to belong to the 'natural antibodies', to be coded by the germline immunoglobulin V genes, and to react with evolutionarily conserved structural cellular components, including nRNP. Our finding that nRNP is one of the target antigens for this polyreactive autoantibody may lead to the elucidation of the origin of the pathogenic IgG and IgA anti-nRNP antibodies found in sera from patients with systemic autoimmune diseases. PMID:1333924
Tan, Bruce K.; Li, Quan-Zhen; Suh, Lydia; Kato, Atsushi; Conley, David B.; Chandra, Rakesh K.; Zhou, Jinchun; Norton, James; Carter, Roderick; Hinchcliff, Monique; Harris, Kathleen; Peters, Anju; Grammer, Leslie C.; Kern, Robert C.; Mohan, Chandra; Schleimer, Robert P.
BACKGROUND Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory condition of the nasal passage and paranasal sinuses characterized by Th2 biased inflammation with elevated levels of BAFF, B-lymphocytes, and immunoglobulins. Since high levels of BAFF are associated with autoimmune diseases, we assessed for evidence of autoimmunity in patients with CRS. OBJECTIVES The objective of this study was to investigate for the presence of autoantibodies in sinonasal tissue from patients with CRS. METHODS Standardized nasal tissue specimens were collected from patients with CRS and control subjects and assayed for immunoglobulin production, autoantibody levels, tissue distribution of immunoglobulins and binding potential of antibodies in nasal tissue using a multiplexed autoantibody microarray, ELISA and immunofluoresence. RESULTS Elevated levels of several specific autoantibodies were found in nasal polyp tissue in comparison with control tissue and inflamed tissue from non-polypoid CRS (CRSsNP) (p<0.05). In particular, nuclear-targeted autoantibodies such as anti-dsDNA IgG and IgA antibodies were found at elevated levels in nasal polyps (p<0.05) and particularly in nasal polyps from patients requiring revision surgery for recurrence. Direct immunofluorescence staining demonstrated diffuse epithelial and sub-epithelial deposition of IgG and increased numbers of IgA secreting plasma cells not seen in control nasal tissue. CONCLUSIONS Autoantibodies, particularly those against nuclear antigens, are present at locally elevated levels in nasal polyps. The presence of autoantibodies suggests that the microenvironment of a nasal polyp promotes the expansion of self-reactive B-cell clones. While the pathogenicity of these antibodies remains to be elucidated, the presence of elevated anti-dsDNA antibodies is associated with a clinically more aggressive form of CRSwNP requiring repeated surgery. PMID:21996343
Asherson, G. L.; Rose, M. Elaine
The finding that the serum of apparently healthy rabbits fixed complement with rabbit liver and kidney has been confirmed. Experimental infection of rabbits with Eimeria stiedae, the cause of hepatic coccidiosis, led to a rise in the titre of serum complement-fixing factors. The rise was statistically significant 14, 21 and 28 days after infection. The factors were regarded as antibodies because they behaved as macroglobulins on diethylaminoethyl—cellulose chromatography and sucrose gradient centrifugation, and as autoantibodies because they fixed complement with the kidney of the rabbits in which they occurred. The antibody reacted with widely distributed antigen(s) with high activity in brain and low activity in skeletal muscle. The possibility that coccidial infection may be responsible for the natural autoantibody of rabbits is discussed. PMID:13965167
Lee, Hon-Chi; Huang, Kristin T. L.; Wang, Xiao-Li; Shen, Win-Kuang
Autoimmune diseases are associated with significant morbidity and mortality, afflicting about 5% of the population of the United States. They encompass a wide range of disorders that affect all organs of the human body and have a predilection for women. In the past, autoimmune pathogenesis was not thought to be a major mechanism for cardiovascular disorders, and potential relationships remain understudied. However, accumulating evidence suggests that a number of vascular and cardiac conditions are autoimmune-mediated. Recent studies indicate that autoantibodies play an important role in the development of cardiac arrhythmias, including atrial fibrillation, modulation of autonomic influences on heart rate and rhythm, conduction system abnormalities, and ventricular arrhythmias. This manuscript will review the current evidence for the role of autoantibodies in the development of cardiac arrhythmias. PMID:21740882
Oppezzo, Pablo; Dighiero, Guillaume
In 1900, the group from Metchnikoff suggested the concept of autoimmunization by demonstrating the presence of autoantibodies in normal conditions; which was opposed to the concept of horror autotoxicus raised by Ehrlich. Landsteiner's description of the transfusion compatibility rules and 50 year-later work from Burnett's and Medawar's groups lead to the clonal deletion theory as a general explanation of tolerance and autoimmunity. However, more recent work succeeded demonstrating that autoreactive B cells constitute a substantial part of the B-cell repertoire and that this autoreactive repertoire secretes the so-called natural autoantibodies (NAA) characterized by their broad reactivity mainly directed against very well conserved public epitopes. They fulfill the definition of an autoantibody since they are self-reactive, but they are not self-specific. As yet, NAA directed against determinants of polymorphism have not been reported. The presence of this repertoire in normal conditions challenges the clonal deletion theory as a unique explanation for self-tolerance. However, if we take into account that this autoreactive B-cell repertoire is not self-specific, this contradiction may not be a real one opposition. Indeed, the Lansteiner's rule that a subject belonging to group A will never produce anti-A antibodies and will always produce natural antibodies against the B-cell group, could never be challenged. Clonal deletion is probably accounting for this phenomenum. However, the serum of healthy adult individuals frequently exhibits low titers of anti-I antibodies, which is a precursor molecule of AB0 antigen system. The mechanism accounting for deletion of B cells directed against critical determinants like antigens A and B in the red blood cell system and allowing the production of autoantibodies against I remain elusive.
Marttinen, A; Sulkanen, S; Mäki, M
We have recently shown that cultured human fibroblasts synthesize and secrete protein molecules that bind to IgA-class anti-reticulin and anti-endomysium antibodies but not to anti-gliadin antibodies in coeliac disease patient sera. In the present report, we describe a reproducible method for purification of these antigen molecules from fibroblast culture medium. Using reversed-phase chromatography as the final purification step, four different protein molecules reacting with coeliac disease patient sera IgA were obtained. In enzyme-linked immunosorbent assay (ELISA) for coeliac disease-specific IgA, a mixture of 0.5 microgram of the four reversed-phase-separated molecules was used as antigen. The optical density values in ELISA of the sera from newly diagnosed coeliac disease patients (n = 34) were 0.740-3.400 (mean 1.830) and in control patients (n = 66) 0.090-0.850 (mean 0.320). Using an arbitrary cut-off level of 0.700, the sensitivity of the present autoantibody test was 100%, specificity 91% and positive predictive value 85%. Our identified autoantigens may generate the production of the classical tissue antibodies, known as anti-reticulin and anti-endomysium antibodies, and may be used as antigen in an immunoassay for the antibodies.
Almogren, Adel; Kerr, Michael A
IgA is by far the most abundant immunoglobulin in humans. It is found in serum and in secretions (SIgA). Unlike any other class of immunoglobulin, each form of IgA occurs naturally in different polymerisation states. In serum, the predominant form of IgA is IgA1 of which around 90% is monomeric and 10% is dimeric or polymeric. The proportion of dimeric/polymeric IgA increases in a number of important diseases, such as IgA nephropathy and in chronic liver disease. In both, there is evidence that further aggregation of dimeric/polymeric IgA is the cause of the characteristic tissue deposition. To investigate the effect of role of IgA polymerisation on the structure and function of IgA, we purified different molecular forms of IgA1 from myeloma serum (monomer, dimer and trimer) and SIgA1 from colostrum. Structural features of these different IgA1 forms were examined following proteolysis using Neisseria gonorrhoeae IgA1 type 2 protease and Streptococcus pneumoniae IgA1 protease. These IgA1 proteases cleave IgA1 at the hinge region and produce Fcalpha and Fab fragments. Western blot analysis demonstrated that the Fcalpha fragments of serum dimeric and trimeric but not monomeric IgA1 aggregated to form multimers resistant to disruption in SDS-PAGE under non-reducing conditions. Size exclusion chromatography under native conditions of cleaved serum dimeric IgA1 demonstrated that aggregation occurs because of structural changes in the IgA per se and was not an effect of the SDS-PAGE system. In the same assay, SIgA1 (dimeric) did not aggregate after digestion. The results suggest an important, previously unrecognised, property of dimeric/polymeric serum IgA1, which might explain its propensity to aggregate and deposit in tissues.
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Berthoux, Francois; Suzuki, Hitoshi; Mohey, Hesham; Maillard, Nicolas; Mariat, Christophe; Novak, Jan; Julian, Bruce A
A prognostic biomarker for IgA nephropathy (IgAN) recurrence after renal transplant is lacking. We followed 96 consecutive first renal transplant recipients with native kidney IgAN (79 men; 92 deceased donors; mean age =48.1 years old) on calcineurin inhibitor-based immunosuppression over 10 years for death, allograft failure, and clinicopathologic recurrence (CPR; clinically evident and biopsy proven). Using time-dependent Cox regression analysis and receiver operating characteristic curves, we assessed prognostic significance of levels of galactose-deficient IgA1 (Gd-IgA1; autoantigen) and Gd-IgA1-specific IgG and IgA autoantibodies in serum obtained at time of transplant or native kidney IgAN diagnosis (30 patients only). Overall, 13 patients died, 34 kidneys failed (17 due to CPR), and 34 patients developed CPR after a mean interval of 5.8 years. Compared with healthy controls (n=30), patients had significantly elevated serum Gd-IgA1 levels at diagnosis and transplant, but levels did not associate with any outcome. Patients also had significantly elevated levels of normalized (but not total) serum Gd-IgA1-specific IgG autoantibodies at diagnosis and transplant, and the level at transplant associated with higher risk of CPR (relative risk, 2.68; 95% confidence interval, 1.26 to 5.71; P=0.01; area under the receiver operating characteristic curve, 0.62; 95% confidence interval, 0.51 to 0.74; P=0.05). Normalized Gd-IgA1-specific IgG autoantibody level remained an independent risk factor for CPR in multivariate analysis. Serum Gd-IgA1-specific IgA autoantibody level did not change between diagnosis and transplant or predict outcome. This study emphasizes post-transplant prognostic value of normalized serum IgG antiglycan autoantibody level in patients with IgAN.
Prigent, Julie; Lorin, Valérie; Kök, Ayrin; Hieu, Thierry; Bourgeau, Salomé
Class‐switched memory B cells are key components of the “reactive” humoral immunity, which ensures a fast and massive secretion of high‐affinity antigen‐specific antibodies upon antigenic challenge. In humans, IgA class‐switched (IgA+) memory B cells and IgA antibodies are abundant in the blood. Although circulating IgA+ memory B cells and their corresponding secreted immunoglobulins likely possess major protective and/or regulatory immune roles, little is known about their specificity and function. Here, we show that IgA+ and IgG+ memory B‐cell antibodies cloned from the same healthy humans share common immunoglobulin gene features. IgA and IgG memory antibodies have comparable lack of reactivity to vaccines, common mucosa‐tropic viruses and commensal bacteria. However, the IgA+ memory B‐cell compartment contains fewer polyreactive clones and importantly, only rare self‐reactive clones compared to IgG+ memory B cells. Self‐reactivity of IgAs is acquired following B‐cell affinity maturation but not antibody class switching. Together, our data suggest the existence of different regulatory mechanisms for removing autoreactive clones from the IgG+ and IgA+ memory B‐cell repertoires, and/or different maturation pathways potentially reflecting the distinct nature and localization of the cognate antigens recognized by individual B‐cell populations. PMID:27469325
Aleyd, Esil; Al, Marjon; Tuk, Cornelis W; van der Laken, Conny J; van Egmond, Marjolein
Autoantibodies, including rheumatoid factor (RF), are an important characteristic of rheumatoid arthritis (RA). Interestingly, several studies reported a correlation between the presence of IgA autoantibodies and worse disease course. We demonstrated previously that triggering the IgA Fc receptor (FcαRI) on neutrophils results in neutrophil recruitment and the release of neutrophil extracellular traps (NETs). Because this can lead to tissue damage, we investigated whether IgA immune complexes in plasma and synovial fluid of RA patients activate neutrophils. RF isotypes were measured with ELISA, and immune complexes were precipitated using polyethylene glycol 6000. Isolated neutrophils were incubated with immune complexes, and activation and release of NETs were determined in the presence or absence of FcαRI-blocking Abs. Plasma and SF of RA patients contained IgM, IgG, and IgA RFs. Patient plasma IgA RF and IgM RF showed a strong correlation. No uptake of IgM and minimal endocytosis of IgG immune complexes by neutrophils was observed, in contrast to avid uptake of IgA complexes. Incubation of neutrophils with immune complexes resulted in the production of reactive oxygen species, as well as the release of NETs, lactoferrin, and chemotactic stimuli. Importantly, activation of neutrophils was reduced when FcαRI was blocked. Neutrophils were activated by IgA immune complexes, which suggests that neutrophils play a role in inducing joint damage in RA patients who have IgA autoantibody complexes, thereby increasing the severity of disease. Blocking FcαRI inhibited neutrophil activation and, as such, may represent an additional attractive novel therapeutic strategy for the treatment of RA. Copyright © 2016 by The American Association of Immunologists, Inc.
Kolka, Ragnhildur; Valdimarsson, Helgi; Bodvarsson, Magnus; Hardarson, Sverrir; Jonsson, Thorbjorn
Defective glycosylation and immune complex (IC) formation may be of primary importance in immunoglobulin A nephropathy (IgAN) pathogenesis. The aim of this study was to determine whether defective IgA1 glycosylation might support renal deposition of IgA and disease activity. IgA was isolated from the serum of 44 IgAN patients and 46 controls and glycosylation analysed by ELISA using glycan-specific lectins. IgA was measured by immunodiffusion and immune complexes by ELISA. IgA subclasses in IC deposits in kidney glomeruli were identified by immunohistochemical methods. A significant increase in N-acetylgalactosamine (GalNAc) in terminal position (p = 0.02) observed in some of the IgAN patients, became more pronounced when sialic acid was removed from IgA1, indicating enhanced expression of α-2,6-sialyltransferase in patients compared with controls (p < 0.0001). Patients with defective galactosylation had lower serum IgA than other IgAN patients (p = 0.003). IgAN patients with both IgA1 and IgA2 glomerular deposits (21.7%) had increased GalNAc in terminal position (p = 0.003). Taken together, our results show that increased IgA glycosylation in IgAN associates with low levels of IgA, concomitant IgA1 and IgA2 glomerular deposits and poor clinical outcome.
McLachlan, S M; Rapoport, B
TPO autoantibodies, the hallmark of human autoimmune thyroid disease, are of IgG class and are associated with thyroid destruction and hypothyroidism. Using the immunoglobulin gene combinatorial library approach, a panel of human monoclonal TPO autoantibodies (expressed as Fab) has been generated from thyroid tissue-infiltrating B cells. TPO-specific Fab closely resemble patients' serum autoantibodies in terms of L chain type, IgG subclass, affinities for TPO as well as epitopes recognized by > 80% of TPO autoantibodies in an individual's serum. TPO autoantibody V region genes are not unique; H chain V genes are usually mutated, while L chain V genes are sometimes in germ-line conformation. The autoantibodies recognize an immunodominant region involving conformational, overlapping epitopes in domains A and B. Finally, TPO autoantibody epitopic fingerprints are distinctive for individual sera, are not associated with hypothyroidism, but are conserved over time (indicating a lack of B cell epitope spreading). Evidence for conservation as well as inheritance of the fingerprints in some families, together with VH gene polymorphisms, may provide insight into the genetic basis of human autoimmune thyroid disease. Furthermore, monoclonal human TPO autoantibodies will be invaluable for B cell presentation of TPO to determine the T cell epitopes involved in TPO autoantibody production. PMID:7544244
Bohr, J; Tysk, C; Yang, P; Danielsson, D; Järnerot, G
BACKGROUND: The aetiology and pathogenesis of collagenous colitis are unknown. Autoimmunity has been suggested, but no serological findings have supported such a theory. AIMS AND METHODS: Serum from 38 collagenous colitis patients and 38 matched healthy controls was analysed for autoantibodies--that is, antinuclear antibodies, antineutrophil cytoplasmic antibodies, smooth muscle and mitochondrial antibodies, rheumatoid factor and antibodies to thyroglobulin and microsomal antigen, together with antibodies to endomysium, gliadin, and cardiolipin. The serum values of IgA, IgG, IgM, and IgG-subclasses, and complement factors C3 and C4 were also determined. RESULTS: In patients with collagenous colitis the mean value of IgM was significantly increased 2.5 g/l (95% CI; 1.9, 3.2) compared with 1.4 g/l (95% CI; 1.2, 1.7) in controls (p = 0.002). Antinuclear antibodies occurred in nine of 38 patients compared with three of 38 controls, this difference was not statistically significant (p = 0.11). The results of all other immunoglobulins, complement factors, and specific antibodies showed no statistical difference between patients and controls. CONCLUSIONS: No firm evidence for an autoimmune genesis in collagenous colitis is found in this study, although the findings of a positive ANA-titre in some patients and an increased IgM level might give some support for this hypothesis. PMID:8881813
Elkon, Keith; Casali, Paolo
Antibodies that react with self-molecules occur in healthy individuals and are referred to as natural antibodies or autoantibodies. Natural autoantibodies are mainly IgM, are encoded by unmutated V(D)J genes and display a moderate affinity for self-antigens. They provide a first line of defense against infections, probably serve housekeeping functions and contribute to the homeostasis of the immune system. By contrast, high-affinity, somatically mutated IgG autoantibodies reflect a pathologic process whereby homeostatic pathways related to cell clearance, antigen-receptor signaling or cell effector functions are disturbed. In some autoimmune disorders, autoantibodies might be present before disease onset, show remarkable specificity and serve as biomarkers providing an opportunity for diagnosis and therapeutic intervention. In organ-specific autoimmune diseases, such as myasthenia gravis or pemphigus, autoantibodies directly bind to and injure target organs. In systemic autoimmune diseases, autoantibodies react with free molecules, such as phospholipids, as well as cell surface and nucleoprotein antigens, forming pathogenic antigen-antibody (immune) complexes. These autoantibodies injure tissues and organs through engagement of Fc gammaR activation of complement as well as internalization and activation of Toll-like receptors. Activation of intracellular Toll-like receptors in plasmacytoid dendritic cells leads to the production of type I interferon, whereas engagement of intracellular Toll-like receptors on antigen-presenting cells stimulates cell activation and the production of other inflammatory cytokines. Thus, immune complexes might perpetuate a positive feedback loop amplifying inflammatory responses.
Singh, Suveer; du Bois, Ron
The pathogenesis of cryptogenic fibrosing alveolitis (CFA) involves injury, an immune/inflammatory response and fibrosis. The cause of the injury is unknown, but the identification of serum autoantibodies makes an autoimmune aetiology attractive. The core study on which this commentary is based used novel cloning and serum screening technologies in order to identify new public and private autoantibodies in sera from 12 patients with CFA. Largely negative conclusions were drawn from that study. However, we suggest that the prevalence of autoantibodies may have been underestimated, that the study was timely and that this approach is worth pursuing further. PMID:11686865
Encephalopathy occasionally occurs in association with thyroid disorders, but most of these are treatable. These encephalopathies include a neuropsychiatric disorder associated with hypothyroidism, called myxedema encephalopathy. Moreover, Hashimoto's encephalopathy (HE) has been recognized as a new clinical disease based on an autoimmune mechanism associated with Hashimoto's thyroiditis. Steroid treatment was successfully administered to these patients. Recently, we discovered that the serum autoantibodies against the NH2-terminal of α-enolase (NAE) are highly specific diagnostic biomarkers for HE. Further, we analyzed serum anti-NAE autoantibodies and the clinical features in many cases of HE from institutions throughout Japan and other countries. Approximately half of assessed HE patients carry anti-NAE antibodies. The age was widely distributed with 2 peaks (20-30 years and 50-70 years). Most HE patients were in euthyroid states, and all patients had anti-thyroid (TG) antibodies and anti-thyroid peroxidase (TPO) antibodies. Anti-TSH receptor (TSH-R) antibodies were observed in some cases. The common neuropsychiatry features are consciousness disturbance and psychosis, followed by cognitive dysfunction, involuntary movements, seizures, and ataxia. Abnormalities on electroencephalography (EEG) and decreased cerebral blood flow on brain SPECT were common findings, whereas abnormal findings on brain magnetic resonance imaging (MRI) were rare. HE patients have various clinical phenotypes such as the acute encephalopathy form, the chronic psychiatric form, and other particular clinical forms, including limbic encephalitis, progressive cerebellar ataxia, and Creutzfeldt-Jakob disease (CJD)-like form. The cerebellar ataxic form of HE clinically mimics spinocerebellar degeneration (SCD) and is characterized by the absence of nystagmus, absent or mild cerebellar atrophy, and lazy background activities on EEG. Taken together, these data suggest that the possibility of
Raad, M; Nohra, E; Chams, N; Itani, M; Talih, F; Mondello, S; Kobeissy, F
Despite the debilitating consequences and the widespread prevalence of brain trauma insults including spinal cord injury (SCI) and traumatic brain injury (TBI), there are currently few effective therapies for most of brain trauma sequelae. As a consequence, there has been a major quest for identifying better diagnostic tools, predictive models, and directed neurotherapeutic strategies in assessing brain trauma. Among the hallmark features of brain injury pathology is the central nervous systems' (CNS) abnormal activation of the immune response post-injury. Of interest, is the occurrence of autoantibodies which are produced following CNS trauma-induced disruption of the blood-brain barrier (BBB) and released into peripheral circulation mounted against self-brain-specific proteins acting as autoantigens. Recently, autoantibodies have been proposed as the new generation class of biomarkers due to their long-term presence in serum compared to their counterpart antigens. The diagnostic and prognostic value of several existing autoantibodies is currently being actively studied. Furthermore, the degree of direct and latent contribution of autoantibodies to CNS insult is still not fully characterized. It is being suggested that there may be an analogy of CNS autoantibodies secretion with the pathophysiology of autoimmune diseases, in which case, understanding and defining the role of autoantibodies in brain injury paradigm (SCI and TBI) may provide a realistic prospect for the development of effective neurotherapy. In this work, we will discuss the accumulating evidence about the appearance of autoantibodies following brain injury insults. Furthermore, we will provide perspectives on their potential roles as pathological components and as candidate markers for detecting and assessing CNS injury.
Vo Ngoc, D T Laura; Krist, Lizette; van Overveld, Frans J; Rijkers, Ger T
The most common humoral immunodeficiency is IgA deficiency. One of the first papers addressing the cellular and molecular mechanisms underlying IgA deficiency indicated that immature IgA-positive B-lymphocytes are present in these patients. This suggests that the genetic background for IgA is still intact and that class switching can take place. At this moment, it cannot be ruled out that genetic as well as environmental factors are involved. Areas covered: A clinical presentation, the biological functions of IgA, and the management of IgA deficiency are reviewed. In some IgA deficient patients, a relationship with a loss-of-function mutation in the TACI (transmembrane activator and calcium-modulating cyclophilin ligand interaction) gene has been found. Many other genes also have been associated. Gut microbiota are an important environmental trigger for IgA synthesis. Expert commentary: Expression of IgA deficiency is due to both genetic and environmental factors and a role for gut microbiota cannot be excluded.
Lee, Jeong-Min; Jang, Young-Saeng; Jin, Bo-Ra; Kim, Sun-Jin; Kim, Hyeon-Jin; Kwon, Bo-Eun; Ko, Hyun-Jeong; Yoon, Sung-Il; Lee, Geun-Shik; Kim, Woan-Sub; Seo, Goo-Young; Kim, Pyeung-Hyeun
Lactoferrin (LF) and retinoic acid (RA) are enriched in colostrum, milk, and mucosal tissues. We recently showed that LF-induced IgA class switching through binding to betaglycan (transforming growth factor-beta receptor III, TβRIII) and activation of canonical TGF-β signaling. We investigated the combined effect of LF and RA on the overall IgA response. An increase in IgA production by LF was further augmented by RA. This combination effect was also evident in Ig germ-line α (GLα) transcription and GLα promoter activity, indicating that LF in cooperation with RA increased IgA isotype switching. We subsequently found that RA enhanced TβRIII expression and that this increase contributed to LF-stimulated IgA production. In addition to the IgA response, LF and RA in combination also enhanced the expression of the gut-homing molecules C-C chemokine receptor 9 (CCR9) and α4β7 on B cells. Finally, peroral administration of LF and RA enhanced the frequency of CCR9(+)IgA(+) plasma cells in the lamina propria. Taken together, these results suggest that LF in cooperation with RA can contribute to the establishment of gut IgA responses.
Mannoor, Kaiissar; Xu, Yang; Chen, Ching
A substantial proportion of circulating antibodies in healthy individuals exhibit self-reactivity. These antibodies, referred to as natural autoantibodies, are thought to arise naturally without actual antigen stimulation as they are present in human cord blood and in mice housed in germfree conditions and fed an antigen-free diet. Natural autoantibodies are mainly of the IgM class, unmutated, and typically polyreactive. They provide critical early protection against pathogens, and play important roles in maintenance of homeostasis and modulation of innate and adaptive immune responses, thereby conferring protection from rampant autoimmune and inflammatory injuries. In this review, we summarize current information regarding the properties of natural autoantibodies and the B cells that produce them, their roles in immunity and autoimmunity, their mechanisms of action, and their therapeutic potential.
Fadeyi, Emmanuel A; Simmons, Julie H; Jones, Mary Rose; Palavecino, Elizabeth L; Pomper, Gregory J
Most cases of autoimmune hemolytic anemia (AIHA) are caused by the production of an autoantibody that targets determinants on red blood cells (RBCs). This autoantibody can be immunoglobulin (Ig) G, IgM, or IgA. Some autoantibodies react optimally at 0° to 4°C (ie, cold agglutinin) and usually are clinically insignificant. High-titer cold agglutinins are associated with IgM autoantibody and complement fixation induced by infectious agents, including the Epstein-Barr virus (EBV). This case report describes a 31-year-old man who had jaundice, a hemoglobin of 6.0 gdL, and was diagnosed with a hemolytic crisis of AIHA. He received a total of 11 RBC transfusions during a 15-hour period without sustained response and later died. The direct antiglobulin test results for this patient were positive, whereas the cold-agglutinin-testing results were negative. We detected EBV DNA in blood via polymerase chain reaction (PCR). We report a rare case of AIHA associated with an IgG autoantibody and exacerbated by EBV infection, causing a fatal hemolytic anemia.
Prigent, Julie; Lorin, Valérie; Kök, Ayrin; Hieu, Thierry; Bourgeau, Salomé; Mouquet, Hugo
Class-switched memory B cells are key components of the "reactive" humoral immunity, which ensures a fast and massive secretion of high-affinity antigen-specific antibodies upon antigenic challenge. In humans, IgA class-switched (IgA(+) ) memory B cells and IgA antibodies are abundant in the blood. Although circulating IgA(+) memory B cells and their corresponding secreted immunoglobulins likely possess major protective and/or regulatory immune roles, little is known about their specificity and function. Here, we show that IgA(+) and IgG(+) memory B-cell antibodies cloned from the same healthy humans share common immunoglobulin gene features. IgA and IgG memory antibodies have comparable lack of reactivity to vaccines, common mucosa-tropic viruses and commensal bacteria. However, the IgA(+) memory B-cell compartment contains fewer polyreactive clones and importantly, only rare self-reactive clones compared to IgG(+) memory B cells. Self-reactivity of IgAs is acquired following B-cell affinity maturation but not antibody class switching. Together, our data suggest the existence of different regulatory mechanisms for removing autoreactive clones from the IgG(+) and IgA(+) memory B-cell repertoires, and/or different maturation pathways potentially reflecting the distinct nature and localization of the cognate antigens recognized by individual B-cell populations. © 2016 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
De Oliveira-Serra, Flavio Augusto; Mosca, Tainá; Santos de Menezes, Maria da Conceição; Carvalho-Neves Forte, Wilma
IgA deficiency is the most common primary immunodeficiency. Early diagnosis and clinical follow-up may improve the quality of life of patients with IgA deficiency. To this end, IgA deficiency should be further studied and better understood on its clinical manifestations. To determine IgA deficiency clinical manifestations. Cross-sectional, retrospective, exploratory study, where the medical records of 39 patients with IgA deficiency were analyzed. Among the analyzed cases, 10 patients were diagnosed with total IgA deficiency and 29 patients with partial IgA deficiency. Partial and total IgA deficiency main clinical manifestations were allergic rhinoconjunctivitis and allergic asthma. In total IgA deficiency, in addition to allergic diseases, a statistically significant number (p < 0.05) of cases of infection-related rhinosinusitis, tonsillitis and conjunctivitis were also observed. This study showed that the main clinical manifestations in IgA deficiency were allergic rhinoconjunctivitis and allergic asthma. In addition, patients with total IgA deficiency showed a significant increase in infection-related rhinosinusitis, tonsillitis and conjunctivitis, when compared with patients with partial IgA deficiency.
Furuya, Yoichi; Kirimanjeswara, Girish S; Roberts, Sean; Racine, Rachael; Wilson-Welder, Jennifer; Sanfilippo, Alan M; Salmon, Sharon L; Metzger, Dennis W
We report that IgA(-/-) mice exhibit specific defects in IgG antibody responses to various polysaccharide vaccines (Francisella tularensis LPS and Pneumovax), but not protein vaccines such as Fluzone. This defect further included responses to polysaccharide-protein conjugate vaccines (Prevnar and Haemophilus influenzae type b-tetanus toxoid vaccine). In agreement with these findings, IgA(-/-) mice were protected from pathogen challenge with protein- but not polysaccharide-based vaccines. Interestingly, after immunization with live bacteria, IgA(+/+) and IgA(-/-) mice were both resistant to lethal challenge and their IgG anti-polysaccharide antibody responses were comparable. Immunization with live bacteria, but not purified polysaccharide, induced production of serum B cell-activating factor (BAFF), a cytokine important for IgG class switching; supplementing IgA(-/-) cell cultures with BAFF enhanced in vitro polyclonal IgG production. Taken together, these findings show that IgA deficiency impairs IgG class switching following vaccination with polysaccharide antigens and that live bacterial immunization can overcome this defect. Since IgA deficient patients also often show defects in antibody responses following immunization with polysaccharide vaccines, our findings could have relevance to the clinical management of this population. Copyright © 2017 Elsevier Ltd. All rights reserved.
Inflammatory myopathies are a heterogeneous group of immune-mediated diseases that involve the skeletal muscle as well as many other organs. In addition to a histological diagnosis at muscle biopsy, the clinical phenotypes of inflammatory myopathies can be defined by the presence of various autoantibodies that are originally detected by RNA or protein immunoprecipitation. However, the correlation between histological features and autoantibodies has not been fully elucidated. Immune-mediated necrotizing myopathy (IMNM), which is characterized by significant necrotic and regeneration muscle fibers with minimal or no inflammatory cell infiltration, is associated with the presence of autoantibodies. IMNM is now classified as a distinct category of inflammatory myopathies, separate from polymyositis, dermatomyositis, and sporadic inclusion body myositis. Here, we divided the autoantibodies of inflammatory myopathies into the following categories: those associated with IMNM, those with activity against aminoacyl transfer RNA synthetase, those associated with dermatomyositis, and those related to other disorders, including overlap syndrome, inclusion body myositis, and primary biliary cirrhosis. The detection of autoantibodies against signal recognition particle or 3-hydroxy-3-methylglutaryl-coenzyme A reductase is useful for the diagnosis of IMNM. The screening of autoantibodies has clinical relevance for managing patients with inflammatory myopathies.
Lee, Jung-Rok; Haddon, D. James; Wand, Hannah E.; Price, Jordan V.; Diep, Vivian K.; Hall, Drew A.; Petri, Michelle; Baechler, Emily C.; Balboni, Imelda M.; Utz, Paul J.; Wang, Shan X.
High titer, class-switched autoantibodies are a hallmark of systemic lupus erythematosus (SLE). Dysregulation of the interferon (IFN) pathway is observed in individuals with active SLE, although the association of specific autoantibodies with chemokine score, a combined measurement of three IFN-regulated chemokines, is not known. To identify autoantibodies associated with chemokine score, we developed giant magnetoresistive (GMR) biosensor microarrays, which allow the parallel measurement of multiple serum antibodies to autoantigens and peptides. We used the microarrays to analyze serum samples from SLE patients and found individuals with high chemokine scores had significantly greater reactivity to 13 autoantigens than individuals with low chemokine scores. Our findings demonstrate that multiple autoantibodies, including antibodies to U1-70K and modified histone H2B tails, are associated with IFN dysregulation in SLE. Further, they show the microarrays are capable of identifying autoantibodies associated with relevant clinical manifestations of SLE, with potential for use as biomarkers in clinical practice.
Lee, Jung-Rok; Haddon, D. James; Wand, Hannah E.; Price, Jordan V.; Diep, Vivian K.; Hall, Drew A.; Petri, Michelle; Baechler, Emily C.; Balboni, Imelda M.; Utz, Paul J.; Wang, Shan X.
High titer, class-switched autoantibodies are a hallmark of systemic lupus erythematosus (SLE). Dysregulation of the interferon (IFN) pathway is observed in individuals with active SLE, although the association of specific autoantibodies with chemokine score, a combined measurement of three IFN-regulated chemokines, is not known. To identify autoantibodies associated with chemokine score, we developed giant magnetoresistive (GMR) biosensor microarrays, which allow the parallel measurement of multiple serum antibodies to autoantigens and peptides. We used the microarrays to analyze serum samples from SLE patients and found individuals with high chemokine scores had significantly greater reactivity to 13 autoantigens than individuals with low chemokine scores. Our findings demonstrate that multiple autoantibodies, including antibodies to U1-70K and modified histone H2B tails, are associated with IFN dysregulation in SLE. Further, they show the microarrays are capable of identifying autoantibodies associated with relevant clinical manifestations of SLE, with potential for use as biomarkers in clinical practice. PMID:27279139
Kusakari, C; Nose, M; Takasaka, T; Yuasa, R; Kato, M; Miyazono, K; Fujita, T; Kyogoku, M
IgA nephropathy (IgAN) is generally thought to be mediated by the glomerular deposition of circulating immune complexes containing IgA as the major antibody component. Upper respiratory infections and tonsillitis often precede IgAN, and in some cases tonsillectomy is effective for the treatment of IgAN. Thus, the tonsil seems to be a unique organ causing initial and/or progressive events to generate nephritogenic immune complexes in IgAN. In this study we focused on the analysis of immunopathological features of the palatine tonsil characteristic of IgAN patients by using an immunohistochemical technique. The IgA1 subclass was demonstrated in follicular dendritic cells (FDC) of the tonsil of IgAN patients, but not in FDC of non-IgAN controls. On the other hand, IgA2, IgG, IgM and C3 did not show any differences in distribution between the two groups. Moreover, the expression of decay-accelerating factor (DAF), an inhibitor of homologous complement activation, and transforming growth factor-beta 1 (TGF-beta 1), an inducer of antibody-producing cells to IgA class switching, in FDC and interdigitating dendritic cells of the tonsil, respectively, which was also clarified in this study for the first time, was found to be identically distributed in the two groups. These findings may support the idea that IgA1, possibly in an immune complex form, is trapped by FDC and plays an important role in the persistent activation of particular B cell repertoires responsible for the onset and/or progression of IgAN.
Kusakari, C; Nose, M; Takasaka, T; Yuasa, R; Kato, M; Miyazono, K; Fujita, T; Kyogoku, M
IgA nephropathy (IgAN) is generally thought to be mediated by the glomerular deposition of circulating immune complexes containing IgA as the major antibody component. Upper respiratory infections and tonsillitis often precede IgAN, and in some cases tonsillectomy is effective for the treatment of IgAN. Thus, the tonsil seems to be a unique organ causing initial and/or progressive events to generate nephritogenic immune complexes in IgAN. In this study we focused on the analysis of immunopathological features of the palatine tonsil characteristic of IgAN patients by using an immunohistochemical technique. The IgA1 subclass was demonstrated in follicular dendritic cells (FDC) of the tonsil of IgAN patients, but not in FDC of non-IgAN controls. On the other hand, IgA2, IgG, IgM and C3 did not show any differences in distribution between the two groups. Moreover, the expression of decay-accelerating factor (DAF), an inhibitor of homologous complement activation, and transforming growth factor-beta 1 (TGF-beta 1), an inducer of antibody-producing cells to IgA class switching, in FDC and interdigitating dendritic cells of the tonsil, respectively, which was also clarified in this study for the first time, was found to be identically distributed in the two groups. These findings may support the idea that IgA1, possibly in an immune complex form, is trapped by FDC and plays an important role in the persistent activation of particular B cell repertoires responsible for the onset and/or progression of IgAN. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7507015
Background Conflicting results regarding changes in mucosal IgA production or in the proportions of IgA plasma cells in the small and large intestines during HIV-infection have been previously reported. Except in individuals repeatedly exposed to HIV-1 but yet remaining uninfected, HIV-specific IgAs are frequently absent in mucosal secretions from HIV-infected patients. However, little is known about the organization and functionality of mucosal B-cell follicles in acute HIV/SIV infection during which a T-dependent IgA response should have been initiated. In the present study, we evaluated changes in B-cell and T-cell subsets as well as the extent of apoptosis and class-specific plasma cells in Peyer’s Patches, isolated lymphoid follicles, and lamina propria. Plasma levels of IgA, BAFF and APRIL were also determined. Results Plasma IgA level was reduced by 46% by 28 days post infection (dpi), and no IgA plasma cells were found within germinal centers of Peyer’s Patches and isolated lymphoid follicles. This lack of a T-dependent IgA response occurs although germinal centers remained functional with no sign of follicular damage, while a prolonged survival of follicular CD4+ T-cells and normal generation of IgG plasma cells is observed. Whereas the average plasma BAFF level was increased by 4.5-fold and total plasma cells were 1.7 to 1.9-fold more numerous in the lamina propria, the relative proportion of IgA plasma cells in this effector site was reduced by 19% (duodemun) to 35% (ileum) at 28 dpi. Conclusion Our data provide evidence that SIV is unable to initiate a T-dependent IgA response during the acute phase of infection and favors the production of IgG (ileum) or IgM (duodenum) plasma cells at the expense of IgA plasma cells. Therefore, an early and generalized default in IgA production takes place during the acute of phase of HIV/SIV infection, which might impair not only the virus-specific antibody response but also IgA responses to other pathogens and
Roggenbuck, D; Somma, V; Schierack, P; Borghi, M O; Meroni, P L
The international consensus for the classification of antiphospholipid syndrome (APS) requires clinical and laboratory criteria to be considered at an equal level for diagnosing APS. Thus, detection of antiphospholipid antibodies (aPL) being a hallmark of APS has been the object of intensive investigation over the past 40 years. However, appropriate detection of aPL still remains a laboratory challenge due to their heterogeneity comprising autoantibodies reactive to different phospholipid-binding plasma proteins, such as beta-2 glycoprotein I (β2GPI) and prothrombin. The relevance of aPL interacting with phospholipids other than cardiolipin (CL, diphosphatidylglycerol), such as phosphatidylserine (PS), remains elusive with regard to the diagnosis of APS. Recently, the concept of aPL profiling has been introduced to assess the risk of thrombotic complications in patients with APS. New assay techniques, apart from enzyme-linked immunosorbent assays (ELISAs) recommended by the international consensus for the classification of APS, have been proposed for multiplexing of aPL testing. Line immunoassays (LIAs) employing a novel hydrophobic solid phase for the simultaneous detection of different aPL seem to be an intriguing alternative. We evaluated a novel multiplex LIA employing a hydrophobic membrane coated with different phospholipid (PL)-binding proteins or PLs. The performance characteristics of this new multiplexing assay technique demonstrated its usefulness for aPL profiling. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Frankowiack, Marcel; Hellman, Lars; Zhao, Yaofeng; Arnemo, Jon M; Lin, Miaoli; Tengvall, Katarina; Møller, Torsten; Lindblad-Toh, Kerstin; Hammarström, Lennart
Low mean concentrations of serum immunoglobulin A (IgA) and an increased frequency of overt IgA deficiency (IgAD) in certain dog breeds raises the question whether it is a breeding-enriched phenomenon or a legacy from the dog's ancestor, the gray wolf (Canis lupus). The IgA concentration in 99 serum samples from 58 free-ranging and 13 captive Scandinavian wolves, was therefore measured by capture ELISA. The concentrations were markedly lower in the wolf serum samples than in the dog controls. Potential differences in the IgA molecule between dogs and wolves were addressed by sequencing the wolf IgA heavy chain constant region encoding gene (IGHA). Complete amino acid sequence homology was found. Detection of wolf and dog IgA was ascertained by showing identity using double immunodiffusion. We suggest that the vast majority of wolves, the ancestor of the dog, are IgA deficient.
Mitsuiki, Noriko; Yang, Xi; Bartol, Sophinus J W; Grosserichter-Wagener, Christina; Kosaka, Yoshiyuki; Takada, Hidetoshi; Imai, Kohsuke; Kanegane, Hirokazu; Mizutani, Shuki; van der Burg, Mirjam; van Zelm, Menno C; Ohara, Osamu; Morio, Tomohiro
X-linked agammaglobulinemia (XLA) is a primary immunodeficiency caused by mutations in Bruton's tyrosine kinase (BTK), and is characterized by markedly decreased numbers of blood B cells and an absence of all immunoglobulin isotypes. We performed whole exome sequencing in a male pediatric patient with dysgammaglobulinemia with IgA deficiency. Genetic analysis revealed a BTK missense mutation (Thr316Ala). To investigate whether a BTK mutation underlay this antibody deficiency with marked decrease of IgA in this patient, we performed functional analyses of B cells and phagocytes, and molecular analyses of somatic hypermutation and class switch recombination. The BTK missense mutation resulted in B cells with reduced BTK and high IgM expression. Equal proportions of CD19(low) and CD19(normal) fractions were observed, and both included naïve and memory B cells. Calcium influx and phospholipase Cγ2 phosphorylation upon IgM stimulation were marginally impaired in CD19(low), but not in CD19(+) B cells. Similar to XLA patients, IgA transcripts showed low SHM levels, whereas IgG transcripts were hardly affected. Our analyses suggest that the BTK mutation likely underlies the disease in this case, and that hypomorphic BTK mutations can result in normal circulating B cell numbers, but specifically impair IgA responses.
Malmborg, A C; Shultz, D B; Luton, F; Mostov, K E; Richly, E; Leung, P S; Benson, G D; Ansari, A A; Coppel, R L; Gershwin, M E; Van de Water, J
Primary biliary cirrhosis (PBC) is a chronic autoimmune liver disease of unknown etiology characterized by high-titer anti-mitochondrial antibodies. The major autoantigen has been identified as the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2). The fact that PDC-E2 is present in all nucleated cells, but autoimmune damage is confined to biliary epithelial cells, prompted us to investigate the possibility that mucosally-derived IgA may be pathogenic for biliary epithelial cells. Serum IgA was purified from six patients with PBC and its localization and ability to penetrate cells was studied using Madine-Darby canine kidney (MDCK) cells transfected with the human IgA receptor (MDCK-pIgR). The potential of IgA to be transported through the cells was studied by a combination of immunohistochemistry and dual color fluorescent microscopy. Interestingly, IgA from all PBC patients co-localized with PDC-E2 (the major autoantigen of PBC) inside the cells; this was demonstrated by dual staining with anti-human IgA and a mouse monoclonal antibody directed to PDC-E2. In contrast, no co-localization was observed for IgA controls. Furthermore, dual staining of liver sections from PBC patients demonstrated co-localization of IgA and PDC-E2, both cytoplasmically and at the apical surface. We postulate that there may be a direct effect of these autoantibodies on the mitochondrial function of biliary epithelial cells. Copyright 1998 Academic Press.
Wang, Aifeng; Wang, Yongping; Wang, Guobao; Zhou, Zhanmei; Xun, Zhang; Tan, Xiaohui
Anti-glomerular basement membrane (anti-GBM) disease is characterized by crescentic glomerulonephritis with immunoglobulin G (IgG) autoantibodies to the non-collagenous (NC1) domain of α3(IV) collagen presenting along the GBM. The patient clinically manifests with rapidly progressive glomerulonephritis (RPGN) with pulmonary hemorrhage (Goodpasture syndrome). In rare cases, other immunocomplexes of IgA or IgM are involved, but their specificities have not been determined. We report a rare case of a 31-year-old female who was diagnosed as having anti-GBM disease with extensive IgA deposits in the mesangium. This patient presented heavy hematuria, proteinuria with increasing creatinine, but no lung hemorrhage. Renal biopsy showed crescentic glomerulonephritis (type Ⅰ) with strong IgA (3+) as lump and branch shape. Therapies with pulse methylprednisolone, plasmapheresis and cyclophosphamide administration were less effective. This case is different from the present type Ⅰ crescentic glomerulonephritis and the specificity of IgA deposits may implicate the pathogenesis of anti-GBM disease.
Ludwig, Ralf J.; Vanhoorelbeke, Karen; Leypoldt, Frank; Kaya, Ziya; Bieber, Katja; McLachlan, Sandra M.; Komorowski, Lars; Luo, Jie; Cabral-Marques, Otavio; Hammers, Christoph M.; Lindstrom, Jon M.; Lamprecht, Peter; Fischer, Andrea; Riemekasten, Gabriela; Tersteeg, Claudia; Sondermann, Peter; Rapoport, Basil; Wandinger, Klaus-Peter; Probst, Christian; El Beidaq, Asmaa; Schmidt, Enno; Verkman, Alan; Manz, Rudolf A.; Nimmerjahn, Falk
Autoantibodies are frequently observed in healthy individuals. In a minority of these individuals, they lead to manifestation of autoimmune diseases, such as rheumatoid arthritis or Graves’ disease. Overall, more than 2.5% of the population is affected by autoantibody-driven autoimmune disease. Pathways leading to autoantibody-induced pathology greatly differ among different diseases, and autoantibodies directed against the same antigen, depending on the targeted epitope, can have diverse effects. To foster knowledge in autoantibody-induced pathology and to encourage development of urgently needed novel therapeutic strategies, we here categorized autoantibodies according to their effects. According to our algorithm, autoantibodies can be classified into the following categories: (1) mimic receptor stimulation, (2) blocking of neural transmission, (3) induction of altered signaling, triggering uncontrolled (4) microthrombosis, (5) cell lysis, (6) neutrophil activation, and (7) induction of inflammation. These mechanisms in relation to disease, as well as principles of autoantibody generation and detection, are reviewed herein. PMID:28620373
Madi, Asaf; Bransburg-Zabary, Sharron; Maayan-Metzger, Ayala; Dar, Gittit; Ben-Jacob, Eshel
In this work, we studied autoantibody repertoires and Ig isotypes in 71 mothers and their 104 healthy newborns (including twins and triplets delivered term or premature). Newborns receive maternal IgG Abs via the placenta before birth, but developing infants must produce their own IgM and IgA Abs. We used an Ag microarray analysis to detect binding to a selection of 295 self-Ags, compared with 27 standard foreign Ags. The magnitude of binding to specific self-Ags was found to be not less than that to the foreign Ags. As expected, each newborn shared with its mother a similar IgG repertoire—manifest as early as the 24th week of gestation. IgM and IgA autoantibody repertoires in cord sera were highly correlated among the newborns and differed from their mothers’ repertoires; the latter differed in sera and milk. The autoantibodies bound to self-Ags known to be associated with tumors and to autoimmune diseases. Thus, autoantibody repertoires in healthy humans—the immunological homunculus—arise congenitally, differ in maternal milk and sera, and mark the potential of the immune system to attack tumors, beneficially, or healthy tissues, harmfully; regulation of the tissue site, the dynamics, and the response phenotype of homuncular autoimmunity very likely affects health. PMID:25917091
Sutton, R. N. P.; Emond, R. T. D.; Thomas, D. B.; Doniach, D.
Autoantibodies were looked for by immunofluorescence (IFL) in seventy-seven cases of infectious mononucleosis (IM) at the onset of symptoms and on recovery, to determine the time of appearance, duration and range of these responses, and to correlate them with serum immunoglobulin and EB virus antibody titres. Antibodies to lymphocyte membrane demonstrated by IFL, now identified with lymphocytotoxins, were present in 46% of patients in the acute stage, persisting for less than 7 weeks. Antibodies to smooth muscle (SMA) or to contractile fibres in other tissue cells including human thyroid and rat hepatocytes, were present in over 70% of cases, some being entirely of IgM class. The highest titres occurred soon after onset and these antibodies also disappeared during convalescence. By contrast ANA, mitochondrial, microsomal and reticulin antibodies, also thyroid and gastric organ-specific reactivity were seen only occasionally owing to the young age group of the patients. In individual cases there was no correlation between the appearance of lymphocyte antibodies and SMA, or between these and the EB virus antibody titres. The autoantibodies produced in this disease are highly selected. It is suggested that clones of B cells are stimulated to make these antibodies by virtue of being infected with EB virus, and that the T-cell clones in the circulation are more likely expanded in order to terminate the infection. PMID:4619789
Dicker, Martina; Maresch, Daniel; Strasser, Richard
IgA nephropathy (IgAN) is a common autoimmune disease that is characterized by formation and deposition of IgA1-containing immune complexes frequently leading to end-stage kidney disease. The IgA1 in these immune complexes carries aberrantly glycosylated O-glycans. In circulating IgA1 these galactose-deficient mucin-type O-glycans are bound by autoantibodies and thus, contribute to immune complex formation and pathogenesis. Even though the disease is associated with the overproduction of aberrant O-glycans on IgA1, specific structure-function-studies of mucin-type O-glycans are limited. Compared to other expression hosts, plants offer the opportunity for de novo synthesis of O-glycans on recombinant glycoproteins as they are lacking the mammalian O-glycosylation pathway. Recently, we demonstrated that Nicotiana benthamiana are suitable for the generation of distinct O-glycans on recombinant IgA1. Here, we expand our engineering repertoire by in planta generation of galactose-deficient and α2,6-sialylated O-glycans which are the prevailing glycans detected on IgA1 from patients with IgAN.
Mohammad, Shekeeb S; Ramanathan, Sudarshini; Brilot, Fabienne; Dale, Russell C
Autoantibodies to the extracellular domain of neuronal proteins cause different neurological conditions with movement disorders as a prominent feature. We reviewed the literature of autoantibody-mediated and autoantibody-associated diseases focusing on anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, autoimmune basal ganglia encephalitis, Sydenham chorea, and the rare syndrome of progressive encephalomyelitis with rigidity and myoclonus. NMDAR encephalitis is a diffuse encephalitis with psychiatric and cognitive features associated with autoantibodies against the NR1 subunit of the NMDAR. The movement disorder phenotype is diverse and often generalized in young children. Although orofacial dyskinesia was the initial movement phenotype, chorea, dystonia, catatonia, and stereotypical movements are now described. The stereotypical movements can be bizarre and include cycling movements and compulsive self-injurious behavior. Autoimmune basal ganglia encephalitis is an inflammatory encephalitis localizing to the basal ganglia that is sometimes associated with serum antibodies against dopamine-2 receptor. Although psychiatric features are common, the dominant problem is a movement disorder, with dystonia-parkinsonism being characteristic. Sydenham chorea is the prototypic poststreptococcal autoimmune neuropsychiatric disorder and several autoantibodies may be involved in disease generation. The syndrome is characterized by a pure chorea, although hypotonia, dysarthria, and emotional lability are common. Progressive encephalomyelitis with rigidity and myoclonus is a rare autoimmune disorder causing rigidity, stimulus sensitive spasms, and myoclonus of nonepileptic origin and is associated with autoantibodies of multiple types including those against the glycine receptor. These disorders are important to recognize and diagnose, as immune therapy can shorten disease duration and improve outcome. Georg Thieme Verlag KG Stuttgart · New York.
Oruc, Zeliha; Oblet, Christelle; Boumediene, Ahmed; Druilhe, Anne; Pascal, Virginie; Le Rumeur, Elisabeth; Cuvillier, Armelle; El Hamel, Chahrazed; Lecardeur, Sandrine; Leanderson, Tomas; Morelle, Willy; Demengeot, Jocelyne; Aldigier, Jean-Claude; Cogné, Michel
IgA1 mesangial deposition is the hallmark of IgA nephropathy and Henoch-Schönlein purpura, the onset of which often follows infections. Deposited IgA has been reported as polymeric, J chain associated, and often, hypogalactosylated but with no information concerning the influence of the IgA repertoire or the link between immune stimuli and IgA structure. We explored these issues in the α1KI mouse model, which produces polyclonal human IgA1 prone to mesangial deposition. Compared with mice challenged by a conventional environment, mice in a specific pathogen-free environment had less IgA deposition. However, serum IgA of specific pathogen-free mice showed more galactosylation and much lower polymerization. Notably, wild-type, α1KI, and even J chain-deficient mice showed increased polymeric serum IgA on exposure to pathogens. Strict germfree conditions delayed but did not completely prevent deposition; mice housed in these conditions had very low serum IgA levels and produced essentially monomeric IgA. Finally, comparing monoclonal IgA1 that had different variable regions and mesangial deposition patterns indicated that, independently of glycosylation and polymerization, deposition might also depend on IgA carrying specific variable domains. Together with IgA quantities and constant region post-translational modifications, repertoire changes during immune responses might, thus, modulate IgA propensity to deposition. These IgA features are not associated with circulating immune complexes and C3 deposition and are more pertinent to an initial IgA deposition step preceding overt clinical symptoms in patients.
Oruc, Zeliha; Oblet, Christelle; Boumediene, Ahmed; Druilhe, Anne; Pascal, Virginie; Le Rumeur, Elisabeth; Cuvillier, Armelle; El Hamel, Chahrazed; Lecardeur, Sandrine; Leanderson, Tomas; Morelle, Willy; Demengeot, Jocelyne; Aldigier, Jean-Claude
IgA1 mesangial deposition is the hallmark of IgA nephropathy and Henoch–Schönlein purpura, the onset of which often follows infections. Deposited IgA has been reported as polymeric, J chain associated, and often, hypogalactosylated but with no information concerning the influence of the IgA repertoire or the link between immune stimuli and IgA structure. We explored these issues in the α1KI mouse model, which produces polyclonal human IgA1 prone to mesangial deposition. Compared with mice challenged by a conventional environment, mice in a specific pathogen–free environment had less IgA deposition. However, serum IgA of specific pathogen–free mice showed more galactosylation and much lower polymerization. Notably, wild-type, α1KI, and even J chain–deficient mice showed increased polymeric serum IgA on exposure to pathogens. Strict germfree conditions delayed but did not completely prevent deposition; mice housed in these conditions had very low serum IgA levels and produced essentially monomeric IgA. Finally, comparing monoclonal IgA1 that had different variable regions and mesangial deposition patterns indicated that, independently of glycosylation and polymerization, deposition might also depend on IgA carrying specific variable domains. Together with IgA quantities and constant region post–translational modifications, repertoire changes during immune responses might, thus, modulate IgA propensity to deposition. These IgA features are not associated with circulating immune complexes and C3 deposition and are more pertinent to an initial IgA deposition step preceding overt clinical symptoms in patients. PMID:26825533
Oka, Kazumasa; Nishimura, Kenji; Kishikawa, Hidefumi; Ichikawa, Yasuji
Background In the pathogenesis of immunoglobulin A nephropathy (IgAN), the IgA1 subclass is more important than the IgA2 subclass. In healthy men, the prevalence of mesangial IgA deposition has been previously investigated. However, it remains unknown whether the presence of urinary abnormalities depends on the subclass of IgA deposition. Materials and methods We researched the subclasses of IgA (IgA1 and IgA2) by the direct immunofluorescence (IF) staining method using specimens in which we identified the deposition of IgA through zero-hour renal transplant biopsies from donors without urinary abnormalities. The samples of the zero-hour biopsies were collected from 46 cases of living renal transplant patients at Nishinomiya Hospital, Hyogo Prefecture, from January 2011 to December 2013. Results In seven of the 46 cases (15%), IgA deposition and C3 in mesangium were confirmed. All seven cases showed IgA1 predominant mesangial deposition on IF. The results of the histological evaluations for all seven cases were Oxford Classification M0.S0.E0.T0. Conclusion This study showed similar patterns of latent mesangial IgA deposition according to IgA subclass and frequency of C3 deposition as IgAN. Latent mesangial IgA deposition may require some, as yet undefined factors, to become clinically apparent as IgAN. PMID:27942230
Oka, Kazumasa; Nishimura, Kenji; Kishikawa, Hidefumi; Ichikawa, Yasuji
In the pathogenesis of immunoglobulin A nephropathy (IgAN), the IgA1 subclass is more important than the IgA2 subclass. In healthy men, the prevalence of mesangial IgA deposition has been previously investigated. However, it remains unknown whether the presence of urinary abnormalities depends on the subclass of IgA deposition. We researched the subclasses of IgA (IgA1 and IgA2) by the direct immunofluorescence (IF) staining method using specimens in which we identified the deposition of IgA through zero-hour renal transplant biopsies from donors without urinary abnormalities. The samples of the zero-hour biopsies were collected from 46 cases of living renal transplant patients at Nishinomiya Hospital, Hyogo Prefecture, from January 2011 to December 2013. In seven of the 46 cases (15%), IgA deposition and C3 in mesangium were confirmed. All seven cases showed IgA1 predominant mesangial deposition on IF. The results of the histological evaluations for all seven cases were Oxford Classification M0.S0.E0.T0. This study showed similar patterns of latent mesangial IgA deposition according to IgA subclass and frequency of C3 deposition as IgAN. Latent mesangial IgA deposition may require some, as yet undefined factors, to become clinically apparent as IgAN.
Sinico, R A; Fornasieri, A; Oreni, N; Benuzzi, S; D'Amico, G
A specific and sensitive enzyme-linked immunosorbent assay (ELISA) was used to detect IgA rheumatoid factor (RF) in sera from 88 patients with IgA nephropathy (IgA GN), a disease characterized by abnormalities of IgA production. Significantly higher levels of IgA antiglobulins were demonstrated in IgA GN patients than in normal healthy controls and patients with other forms of chronic primary glomerulonephritis (mean +/- SEM 28.4 +/- 6.6 vs 6.0 +/- 0.4 and 8.3 +/- 1.2 micrograms/ml respectively; p less than 0.002). Interestingly, in contrast to rheumatoid arthritis, IgA RF activity was not associated with IgM antiglobulins. Analysis of sera fractionated by gel chromatography at acid pH revealed that anti-IgG activity resided predominantly in the polymeric fractions of IgA as confirmed by the ability to bind "free" secretory component. Several findings in patients with IgA GN suggest that the IgA deposited in the glomeruli is polymeric, and levels of circulating macromolecular IgA are increased. Our findings confirm a general perturbation of IgA metabolism in this disease. Although the polymeric nature of the IgA RF is suggestive of a mucosal origin, additional evidence is needed to confirm this hypothesis.
Gunawardena, H; Wedderburn, L R; Chinoy, H; Betteridge, Z E; North, J; Ollier, W E R; Cooper, R G; Oddis, C V; Ramanan, A V; Davidson, J E; McHugh, N J
The identification of novel autoantibodies in juvenile dermatomyositis (DM) may have etiologic and clinical implications. The aim of this study was to describe autoantibodies to a 140-kd protein in children recruited to the Juvenile DM National Registry and Repository for UK and Ireland. Clinical data and sera were collected from children with juvenile myositis. Sera that recognized a 140-kd protein by immunoprecipitation were identified. The identity of the p140 autoantigen was investigated by immunoprecipitation/immunodepletion, using commercial monoclonal antibodies to NXP-2, reference anti-p140, and anti-p155/140, the other autoantibody recently described in juvenile DM. DNA samples from 100 Caucasian children with myositis were genotyped for HLA class II haplotype associations and compared with those from 864 randomly selected UK Caucasian control subjects. Sera from 37 (23%) of 162 patients with juvenile myositis were positive for anti-p140 autoantibodies, which were detected exclusively in patients with juvenile DM and not in patients with juvenile DM-overlap syndrome or control subjects. No anti-p140 antibody-positive patients were positive for other recognized autoantibodies. Immunodepletion suggested that the identity of p140 was consistent with NXP-2 (the previously identified MJ autoantigen). In children with anti-p140 antibodies, the association with calcinosis was significant compared with the rest of the cohort (corrected P < 0.005, odds ratio 7.0, 95% confidence interval 3.0-16.1). The clinical features of patients with anti-p140 autoantibodies were different from those of children with anti-p155/140 autoantibodies. The presence of HLA-DRB1*08 was a possible risk factor for anti-p140 autoantibody positivity. This study has established that anti-p140 autoantibodies represent a major autoantibody subset in juvenile DM. This specificity may identify a further immunogenetic and clinical phenotype within the juvenile myositis spectrum that includes an
AVILA, J L; ROJAS, M; AVILA, A
An antibody reactive with cholesterol sulphate (CS) was characterized in human sera by ELISA, erythrocyte and liposome absorption. This antibody was found evenly distributed between the IgA and IgM classes, and whilst this was present at low titres in the serum of 16% of healthy individuals studied, it was significantly elevated in 78% of Trypanosoma cruzi-infected subjects. No association was found between antibody levels and the degree of myocardial damage. No significant difference in immunoreactivity was found between healthy and chagasic subjects using dehydroepiandrosterone sulphate and pregnenolone sulphate and cholesterol, ergosterol, lanosterol, stigmastanol, β-stigmasterol, pregnenolone, prednisolone and dehydroepiandrosterone as antigens, suggesting that in chagasic sera the whole sterol molecule is important for optimal antibody binding. CS-reactive antibodies were easily purified by absorption either with CS-bearing liposomes or with dextran sulphate gel and further elution with 1.5 m NaCl. The optimal pH of CS–antibody interaction was 4.0 with 85% binding at pH 7.0. Polylysine strongly decreased the binding of these antibodies to the corresponding antigen. Furthermore, these antibodies were strongly absorbed by rabbit and guinea pig erythrocyte but not by rat or human erythrocyte. In contrast with anti-sulphatide antibodies, no significant increase in CS-reactive antibodies was found in dilated cardiomyopathies. Whilst CS itself was not detected in T. cruzi lipid extracts, there is an unidentified sulphated sterol, which migrates close to standard CS and which strongly binds chagasic but not control sera. This latter sterol might be acting in chagasic patients as a powerful antigen, triggering specific autoantibody production. PMID:8565284
Planer, Joseph D; Peng, Yangqing; Kau, Andrew L; Blanton, Laura V; Ndao, I Malick; Tarr, Phillip I; Warner, Barbara B; Gordon, Jeffrey I
Immunoglobulin A (IgA), the major class of antibody secreted by the gut mucosa, is an important contributor to gut barrier function. The repertoire of IgA bound to gut bacteria reflects both T-cell-dependent and -independent pathways, plus glycans present on the antibody's secretory component. Human gut bacterial taxa targeted by IgA in the setting of barrier dysfunction are capable of producing intestinal pathology when isolated and transferred to gnotobiotic mice. A complex reorientation of gut immunity occurs as infants transition from passively acquired IgA present in breast milk to host-derived IgA. How IgA responses co-develop with assembly of the microbiota during this period remains poorly understood. Here, we (1) identify a set of age-discriminatory bacterial taxa whose representations define a program of microbiota assembly and maturation during the first 2 postnatal years that is shared across 40 healthy twin pairs in the USA; (2) describe a pattern of progression of gut mucosal IgA responses to bacterial members of the microbiota that is highly distinctive for family members (twin pairs) during the first several postnatal months then generalizes across pairs in the second year; and (3) assess the effects of zygosity, birth mode, and breast feeding. Age-associated differences in these IgA responses can be recapitulated in young germ-free mice, colonized with faecal microbiota obtained from two twin pairs at 6 and 18 months of age, and fed a sequence of human diets that simulate the transition from milk feeding to complementary foods. Most of these responses were robust to diet, suggesting that 'intrinsic' properties of community members play a dominant role in dictating IgA responses. The approach described can be used to define gut mucosal immune development in health and disease states and to help discover ways of repairing or preventing perturbations in this facet of host immunity.
Mackie, D P; Meneely, D J; Pollock, D A; Logan, E F
The role of the IgA antibody to Streptococcus agalactiae found in the whey of milks 12 hours after the first intramammary infection of six Friesian first lactation heifers was assessed using an in vitro bactericidal assay. The mean percentage kill of the streptococci by neutrophils in the presence of these wheys was 36.2% while the equivalent figure for the non-infected quarter whey was 0%. When the IgA antibody was absorbed from the infected quarter wheys using class specific IgA antiserum cross linked with glutaraldehyde the percentage kill of the test system fell to 0%. Elution of the absorbed antibody partially restored the activity to a mean percentage kill of 18.2%. The results indicated that the IgA antibody found in infected quarter whey during the acute stages of intramammary infection with Streptococcus agalactiae was responsible for the opsonic activity which pertained at that time.
Lai, Kar Neng
Since its first description in 1968, IgA nephropathy has remained the most common form of idiopathic glomerulonephritis leading to chronic kidney disease in developed countries. The exact pathogenesis of IgA nephropathy is still not well defined. Current data implicate an important genetic factor, especially in promoting the overproduction of an aberrant form of IgA1. The immunochemical aberrancy of IgA nephropathy is characterized by the undergalactosylation of O-glycans in the hinge region of IgA1. However, such aberrant glycosylation alone does not cause renal injury. The next stage of disease development requires the formation of glycan-specific IgG and IgA antibodies that recognize the undergalactosylated IgA1 molecule. These antibodies often have reactivity against antigens from extrinsic microorganisms and might arise from recurrent mucosal infection. B cells that respond to mucosal infections, particularly tonsillitis, might produce the nephritogenic IgA1 molecule. With increased immune-complex formation and decreased clearance owing to reduced uptake by the liver, IgA1 binds to the glomerular mesangium via an as yet unidentified receptor. Glomerular IgA1 deposits trigger the local production of cytokines and growth factors, leading to the activation of mesangial cells and the complement system. Emerging data suggest that mesangial-derived mediators following glomerular deposition of IgA1 lead to podocyte and tubulointerstitial injury via mesangio-podocytic-tubular crosstalk. This Review summarizes the latest findings in the pathogenesis of IgA nephropathy.
Suzuki, S; Gejyo, F; Nakatomi, Y; Odani, S; Sato, H; Arakawa, M
We have recently demonstrated glomerular deposition of outer membranes of Haemophilus parainfluenzae (HP) antigens (OMHP) and the presence of IgA antibody against OMHP in patients with IgA nephropathy (IgA-N). In this study, we analyzed IgA-, IgG-, and IgM-classes of antibodies against OMHP, and the relationship between these antibodies and renal lesions in IgA-N. The subjects included 44 patients with IgA-N and 62 patients with outer glomerular diseases (OGD); the latter group consisted of 23 patients with predominantly IgG or IgM deposits and small amounts of IgA in the mesangium (group A), and 39 with IgG or IgM deposits without IgA (group B). IgA, IgG, and IgM antibodies against OMHP in patients sera were detected by enzyme-linked immunosorbent assay (ELISA). Immunoblotting demonstrated that the IgA, IgG, and IgM antibodies against OMHP in the sera of IgA-N patients bound to components of OMHP with molecular weights of 19.5, 30, and 40.5 kD. The amino acid compositions of these three OMHP components were similar to those reported for the outer membrane protein (OMP) P6 precursor, OMP P5, and OMP P2 (porin) of Haemophilus influenzae. Both IgA-N and group A patients, (i.e. those with IgA-related renal disease), demonstrated a significantly higher level of IgA antibodies against OMHP than did group B patients. However, only IgA-N patients revealed a significant correlation between the IgA-antibody titer and degree of glomerular changes. IgA-N patients with macroscopic hematuria or arterio(lo)sclerosis had a significantly higher IgA antibody titer than other IgA-N patients. There was no relationship between renal lesions and IgG or IgM antibody titers in any group. These findings suggest that IgA antibodies against OMHP are significantly increased in patients with IgA-related renal disease compared to those without mesangial IgA deposits and that a significant relationship between these antibodies and renal lesions exists only in patients with IgA-N.
Paul, S; Said, S I; Thompson, A B; Volle, D J; Agrawal, D K; Foda, H; de la Rocha, S
Vasoactive intestinal peptide (VIP) is a potent relaxant of the airway smooth muscle. In this study, VIP-binding autoantibodies were observed in the plasma of 18% asthma patients and 16% healthy subjects. Immunoprecipitation studies and chromatography on DEAE-cellulose and immobilized protein G indicated that the plasma VIP-binding activity was largely due to IgG antibodies. Saturation analysis of VIP binding by the plasmas suggested the presence of one or two classes of autoantibodies, distinguished by their apparent equilibrium affinity constants (Ka). The autoantibodies from asthma patients exhibited a larger VIP-binding affinity compared to those from healthy subjects (Ka 7.8 x 10(9) M-1 and 0.13 x 10(9) M-1, respectively; P less than 0.005). The antibodies were specific for VIP, judged by their poor reaction with peptides bearing partial sequence homology with VIP (peptide histidine isoleucine, growth hormone releasing factor and secretin). IgG prepared from the plasma of an antibody-positive asthma patient inhibited the saturable binding of 125I-VIP by receptors in guinea pig lung membranes (by 39-59%; P less than 0.001). These observations are consistent with a role for the VIP autoantibodies in the airway hyperresponsiveness of asthma.
Nogaki, Fumiaki; Oida, Emi; Kamata, Tadashi; Kobayashi, Ikei; Nomura, Keiko; Suyama, Katsuo; Tahara, Sachiko; Ono, Takahiko; Miyawaki, Shigeki; Serikawa, Tadao; Yoshida, Haruyoshi; Kita, Toru; Muso, Eri
The high IgA (HIGA) strain of ddY mice is an inbred model of IgA nephropathy (IgAN), established by selective mating of outbred ddY mice. HIGA mice show high levels of serum IgA and glomerulonephritis with mesangial IgA deposition. To identify the genetic loci responsible for hyperserum IgA and glomerular IgA deposition in this strain, quantitative trait loci analysis was carried out. By crossing HIGA with BALB/c mice, 244 F2 generations were produced. Serum IgA levels and glomerular IgA deposition were examined at 40 weeks of age. Genetic markers were typed at 105 microsatellites and the quantitative trait loci of hyperserum IgA and glomerular IgA deposition were confirmed using Map Manager QTX software. Two significant quantitative trait loci of hyperserum IgA were identified on chromosome 2 [logarithm of odds (LOD) = 5.01] and chromsome 4 (LOD = 4.45), and a suggestive quantitative trait locus of hyperserum IgA was located on chromosome 1 (LOD = 3.49). On chromosome 15, a significant quantitative trait locus of glomerular IgA deposition was identified (LOD = 4.40) without the hyperserum IgA locus. Serum IgA level was weakly correlated with the intensity of glomerular IgA in 244 F2 mice; however, the quantitative trait loci of hyperserum IgA were not significantly associated with glomerular IgA deposition. These findings indicate that, in HIGA mice, glomerular IgA deposition is mainly regulated by a quantitative trait locus on chromosome 15, and hyperserum IgA synergistically but weakly affect glomerular IgA deposition. The immune disturbance similar to IgAN was revealed to be under multigenic control in HIGA mice.
Wu, W; Sun, M; Chen, F; Cao, A T; Liu, H; Zhao, Y; Huang, X; Xiao, Y; Yao, S; Zhao, Q; Liu, Z; Cong, Y
Intestinal IgA, which is regulated by gut microbiota, has a crucial role in maintenance of intestinal homeostasis and in protecting the intestines from inflammation. However, the means by which microbiota promotes intestinal IgA responses remain unclear. Emerging evidence suggests that the host can sense gut bacterial metabolites in addition to pathogen-associated molecular patterns and that recognition of these small molecules influences host immune response in the intestines and beyond. We reported here that microbiota metabolite short-chain fatty acid acetate promoted intestinal IgA responses, which was mediated by "metabolite-sensing" GPR43. GPR43(-/-) mice demonstrated lower levels of intestinal IgA and IgA(+) gut bacteria compared with those in wild type (WT) mice. Feeding WT but not GPR43(-/-) mice acetate but not butyrate promoted intestinal IgA response independent of T cells. Acetate promoted B-cell IgA class switching and IgA production in vitro in the presence of WT but not GPR43(-/-) dendritic cells (DCs). Mechanistically, acetate-induced DC expression of Aldh1a2, which converts Vitamin A into its metabolite retinoic acid (RA). Moreover, blockade of RA signaling inhibited the acetate induction of B-cell IgA production. Our studies thus identified a new pathway by which microbiota promotes intestinal IgA response through its metabolites.
Wu, Wei; Sun, Mingming; Chen, Feidi; Cao, Anthony T; Liu, Han; Zhao, Ye; Huang, Xiangsheng; Xiao, Yi; Yao, Suxia; Zhao, Qihong; Liu, Zhanju; Cong, Yingzi
Intestinal IgA, which is regulated by gut microbiota, plays a crucial role in maintenance of intestinal homeostasis and in protecting the intestines from inflammation. However, the means by which microbiota promotes intestinal IgA responses remain unclear. Emerging evidence suggests that the host can sense gut bacterial metabolites in addition to pathogen-associated molecular patterns and that recognition of these small molecules influences host immune response in the intestines and beyond. We reported here that microbiota metabolite short-chain fatty acid acetate promoted intestinal IgA responses, which was mediated by “metabolite-sensing” GPR43. GPR43−/− mice demonstrated lower levels of intestinal IgA and IgA+ gut bacteria compared to those in WT mice. Feeding WT but not GPR43−/− mice acetate but not butyrate promoted intestinal IgA response independent of T cells. Acetate promoted B cell IgA class switching and IgA production in vitro in the presence of WT but not GPR43−/− dendritic cells (DC). Mechanistically, acetate induced DC expression of Aldh1a2, which converts Vitamin A into its metabolite retinoic acid (RA). Moreover, blockade of RA signaling inhibited the acetate induction of B cell IgA production. Our studies thus identified a new pathway by which microbiota promotes intestinal IgA response through its metabolites. PMID:27966553
Berthelot, Laureline; Papista, Christina; Maciel, Thiago T; Biarnes-Pelicot, Martine; Tissandie, Emilie; Wang, Pamela H M; Tamouza, Houda; Jamin, Agnès; Bex-Coudrat, Julie; Gestin, Aurelie; Boumediene, Ahmed; Arcos-Fajardo, Michelle; England, Patrick; Pillebout, Evangéline; Walker, Francine; Daugas, Eric; Vrtosvnik, François; Flamant, Martin; Benhamou, Marc; Cogné, Michel; Moura, Ivan C; Monteiro, Renato C
IgA nephropathy (IgAN) is a common cause of renal failure worldwide. Treatment is limited because of a complex pathogenesis, including unknown factors favoring IgA1 deposition in the glomerular mesangium. IgA receptor abnormalities are implicated, including circulating IgA-soluble CD89 (sCD89) complexes and overexpression of the mesangial IgA1 receptor, TfR1 (transferrin receptor 1). Herein, we show that although mice expressing both human IgA1 and CD89 displayed circulating and mesangial deposits of IgA1-sCD89 complexes resulting in kidney inflammation, hematuria, and proteinuria, mice expressing IgA1 only displayed endocapillary IgA1 deposition but neither mesangial injury nor kidney dysfunction. sCD89 injection into IgA1-expressing mouse recipients induced mesangial IgA1 deposits. sCD89 was also detected in patient and mouse mesangium. IgA1 deposition involved a direct binding of sCD89 to mesangial TfR1 resulting in TfR1 up-regulation. sCD89-TfR1 interaction induced mesangial surface expression of TGase2 (transglutaminase 2), which in turn up-regulated TfR1 expression. In the absence of TGase2, IgA1-sCD89 deposits were dramatically impaired. These data reveal a cooperation between IgA1, sCD89, TfR1, and TGase2 on mesangial cells needed for disease development. They demonstrate that TGase2 is responsible for a pathogenic amplification loop facilitating IgA1-sCD89 deposition and mesangial cell activation, thus identifying TGase2 as a target for therapeutic intervention in this disease.
Rollino, Cristiana; Vischini, Gisella; Coppo, Rosanna
In this paper we concentrate on the role of infections in IgA nephropathy both from a pathogenetic and clinic point of view. The current hypotheses as regards the role of infections in the pathogenesis of IgA nephropathy are: (a) role of particular pathogens, (b) chronic exposure to mucosal infections, (c) abnormal handling of commensal microbes (gut microbiota). We also focus on particular infections reported in association with classic IgA nephropathy (HIV, malaria, Chlamydia, Lyme disease), as well as on IgA dominant-infection-associated glomerulonephritis. This is a unique form of glomerulonephritis, where IgA deposition is dominant. It is mostly recognized in old, diabetic patients and in association with staphylococcal infection.
Macpherson, Andrew J; Geuking, Markus B; Slack, Emma; Hapfelmeier, Siegfried; McCoy, Kathy D
Immunoglobulin A (IgA) is the main secretory immunoglobulin of mucous membranes and is powerfully induced by the presence of commensal microbes in the intestine. B cells undergo class switch recombination to IgA in the mucosa-associated lymphoid tissues, particularly mesenteric lymph nodes (MLNs) and Peyer's patches, through both T-dependent and T-independent pathways. IgA B cells primed in the mucosa traffic from the intestinal lymphoid structures, initially through the lymphatics and then join the bloodstream, to home back to the intestinal mucosa as IgA-secreting plasma cells. Once induced, anti-bacterial IgA can be extremely long-lived but is replaced if there is induction of additional IgA specificities by other microbes. The mucosal immune system is anatomically separated from the systemic immune system by the MLNs, which act as a firewall to prevent penetration of live intestinal bacteria to systemic sites. Dendritic cells sample intestinal bacteria and induce B cells to switch to IgA. In contrast, intestinal macrophages are adept at killing extracellular bacteria and are able to clear bacteria that have crossed the mucus and epithelial barriers. There is both a continuum between innate and adaptive immune mechanisms and compartmentalization of the mucosal immune system from systemic immunity that function to preserve host microbial mutualism.
Burbelo, Peter D; Lebovitz, Evan E; Bren, Kathleen E; Bayat, Ahmad; Paviol, Scott; Wenzlau, Janet M; Barriga, Katherine J; Rewers, Marian; Harlan, David M; Iadarola, Michael J
Type I diabetes (T1D) is an autoimmune disease characterized by destruction of insulin-producing β-cells in the pancreas. Although several islet cell autoantigens are known, the breadth and spectrum of autoantibody targets has not been fully explored. Here the luciferase immunoprecipitation systems (LIPS) antibody profiling technology was used to study islet and other organ-specific autoantibody responses in parallel. Examination of an initial cohort of 93 controls and 50 T1D subjects revealed that 16% of the diabetic subjects showed anti-gastric ATPase autoantibodies which did not correlate with autoantibodies against GAD65, IA2, or IA2-β. A more detailed study of a second cohort with 18 potential autoantibody targets revealed marked heterogeneity in autoantibody responses against islet cell autoantigens including two polymorphic variants of ZnT8. A subset of T1D subjects exhibited autoantibodies against several organ-specific targets including gastric ATPase (11%), thyroid peroxidase (14%), and anti-IgA autoantibodies against tissue transglutaminase (12%). Although a few T1D subjects showed autoantibodies against a lung-associated protein KCNRG (6%) and S100-β (8%), no statistically significant autoantibodies were detected against several cytokines. Analysis of the overall autoantibody profiles using a heatmap revealed two major subgroups of approximately similar numbers, consisting of T1D subjects with and without organ-specific autoantibodies. Within the organ-specific subgroup, there was minimal overlap among anti-gastric ATPase, anti-thyroid peroxidase, and anti-transglutaminase seropositivity, and these autoantibodies did not correlate with islet cell autoantibodies. Examination of a third cohort, comprising prospectively collected longitudinal samples from high-risk individuals, revealed that anti-gastric ATPase autoantibodies were present in several individuals prior to detection of islet autoantibodies and before clinical onset of T1D. Taken together
Kalantari-Dehaghi, Mina; Anhalt, Grant J; Camilleri, Michael J; Chernyavsky, Alex I; Chun, Sookhee; Felgner, Philip L; Jasinskas, Algis; Leiferman, Kristin M; Liang, Li; Marchenko, Steve; Nakajima-Sasaki, Rie; Pittelkow, Mark R; Zone, John J; Grando, Sergei A
Pemphigus vulgaris (PV) is a mucocutaneous blistering disease characterized by IgG autoantibodies against the stratified squamous epithelium. Current understanding of PV pathophysiology does not explain the mechanism of acantholysis in patients lacking desmoglein antibodies, which justifies a search for novel targets of pemphigus autoimmunity. We tested 264 pemphigus and 138 normal control sera on the multiplexed protein array platform containing 701 human genes encompassing many known keratinocyte cell-surface molecules and members of protein families targeted by organ-non-specific PV antibodies. The top 10 antigens recognized by the majority of test patients' sera were proteins encoded by the DSC1, DSC3, ATP2C1, PKP3, CHRM3, COL21A1, ANXA8L1, CD88 and CHRNE genes. The most common combinations of target antigens included at least one of the adhesion molecules DSC1, DSC3 or PKP3 and/or the acetylcholine receptor CHRM3 or CHRNE with or without the MHC class II antigen DRA. To identify the PV antibodies most specific to the disease process, we sorted the data based on the ratio of patient to control frequencies of antigen recognition. The frequency of antigen recognition by patients that exceeded that of control by 10 and more times were the molecules encoded by the CD33, GP1BA, CHRND, SLC36A4, CD1B, CD32, CDH8, CDH9, PMP22 and HLA-E genes as well as mitochondrial proteins encoded by the NDUFS1, CYB5B, SOD2, PDHA1 and FH genes. The highest specificity to PV showed combinations of autoantibodies to the calcium pump encoded by ATP2C1 with C5a receptor plus DSC1 or DSC3 or HLA-DRA. The results identified new targets of pemphigus autoimmunity. Novel autoantibody signatures may help explain individual variations in disease severity and treatment response, and serve as sensitive and specific biomarkers for new diagnostic assays in PV patients.
Otani, Masako; Nakata, Junichiro; Kihara, Masao; Leroy, Valérie; Moll, Solange; Wada, Yoshinao
Structural aberrations of O-linked glycans present in the IgA1 hinge region are associated with IgA nephropathy, but their contribution to its pathogenesis remains incompletely understood. In this study, mice implanted with hybridoma secreting 6-19 IgA anti-IgG2a rheumatoid factor, but not 46-42 IgA rheumatoid factor bearing the same IgA allotype, developed mesangial deposits consisting of IgA, IgG2a, and C3. Studies in immunoglobulin- and C3-deficient mice revealed that the development of these glomerular lesions required the formation of IgA-IgG2a immune complexes and subsequent activation of complement. The proportion of polymeric and monomeric forms, the IgG2a-binding affinity, and the serum levels of IgA-IgG2a immune complexes were similar between 6-19 IgA– and 46-42 IgA–injected mice. In contrast, the analysis of oligosaccharide structures revealed highly galactosylated O-linked glycans in the hinge region of 6-19 IgA and poorly O-glycosylated in the hinge region of 46-42 IgA. Furthermore, the structure of N-linked glycans in the CH1 domain was the complex type in 6-19 IgA and the hybrid type in 46-42 IgA. In summary, this study demonstrates the presence of O-linked glycans in the hinge region of mouse IgA and suggests that 6-19 IgA rheumatoid factor–induced GN could serve as an experimental model for IgA nephropathy. PMID:22193386
Watson, Rachael; Lindner, Susanne; Bordereau, Pauline; Hunze, Eva-Maria; Tak, Federico; Ngo, Stéphanie; Zipfel, Peter F; Skerka, Christine; Dragon-Durey, Marie-Agnes; Marchbank, Kevin J
The screening of all atypical haemolytic uraemic syndrome (aHUS) patients for factor H autoantibodies is best practice. However, there is no consensus assay for the reporting of factor H autoantibody titres. In this study, three European complement laboratories with expertise in the field of autoantibody testing address this by systematically evaluating several ELISA methods used for the detection of factor H autoantibodies. All methods tested adequately detect high titre samples. However, this study recommends the Paris method for the detection and reporting of factor H autoantibodies to be used when setting up a factor H autoantibody screen. The importance of individual sample background subtraction in these ELISA tests was established. The use of a relative or arbitrary unit index with a common positive and negative serum allowed for consistent comparison of findings from different test centres. Therefore, it is recommended that a standard arbitrary unit scale based on a titration curve from a common positive anti-serum be adopted to allow future establishment of the relative importance of particular titres of factor H autoantibodies in aHUS. Systematic assay for the presence of factor H autoantibodies in patients using the Paris method will provide the longitudinal analysis needed to fully establish the importance of factor H autoantibodies in disease. This will feed into additional research to clarify whether additional factors have a bearing on the phenotype/outcome of autoimmune aHUS. Copyright © 2013 Elsevier GmbH. All rights reserved.
Kanno, Yoshiya; Ohtsuka, Hiromichi; Yoshikawa, Yasunaga; Watanabe, Kiyotaka; Orino, Koichi
Anti-ferritin autoantibody is a ferritin-binding protein commonly found in mammals; it is thought to form an immune complex with ferritin and thereby mediate the rapid clearance of circulating ferritin. The aim of this study is to determine concentrations of ferritin and anti-ferritin autoantibodies (immunoglobulin (Ig)M, IgG and IgA) in serum and colostrum of Holstein (H) and Japanese Black (JB) cows within 24 h of normal calving. Blood and colostrum samples were collected from cows of various ages (2-11 years) and calving number (1-8 live births). Mean ferritin concentrations were higher in colostrum than in serum for both breeds, and higher colostrum ferritin concentrations were found in H than JB cows. IgA antibodies in serum and colostrum from both breeds had negligible ferritin-binding activity. For both breeds, IgM and IgG antibodies had higher ferritin-binding activity in colostrum than in serum. There was a significant correlation between IgM and IgG ferritin-binding activities in serum and colostrum of H and JB cows. These results suggest that ferritin and IgM and IgG autoantibodies are actively transferred from the blood stream to the colostrum at prepartum or early lactation.
Sakano, T; Hosokawa, A; Horino, N; Hyodo, S; Kishi, T; Suzawa, T; Kittaka, E; Sakura, N; Usui, T
We report a patient with low serum IgA levels and persistent pulmonary infection. In spite of the normal contents of serum IgG and IgM, the patient had a deficiency for plasma cell differentiation of all major classes of immunoglobulins (IgG, IgA and IgM). Cross culture systems between normal T or B cells and the patient's T or B cells showed a defect of both T and B cell function.
Busse, Stefan; Busse, Mandy; Brix, Britta; Probst, Christian; Genz, Axel; Bogerts, Bernhard; Stoecker, Winfried; Steiner, Johann
N-methyl-D-aspartate glutamate receptors (NMDA-R) play a key role in learning and memory. Therefore, they may be involved in the pathophysiology of dementia. NMDA-R autoantibodies directed against the NR1a subunit of the NMDA-R, which were first identified as a specific marker for a severe form of encephalitis, cause a decrease in NMDA-Rs, resulting in cognitive impairment and psychosis. We examined the prevalence of NR1a NMDA-R autoantibodies in the serum and cerebrospinal fluid (CSF) of 24 patients with Alzheimer's disease (AD), 20 patients with subcortical ischemic vascular dementia (SIVD), and 274 volunteers without neuropsychiatric disorder. The latter cases showed an association of seropositivity with age. Notably, the overall seroprevalence was not statistically different between dementia patients and matched controls. Further analysis of the patient samples showed that four patients with AD and three patients with SIVD had positive NMDA-R IgM, IgG, and/or IgA autoantibody titers in serum. These patients suffered from psychosis (with the exception of one case). CSF samples were negative for NMDA-R autoantibodies. We conclude that the seroprevalence of NMDA-R-directed autoantibodies is age-related. It has to be clarified by larger studies whether NMDA-R autoantibodies in peripheral blood may predispose patients with AD and SIVD to susceptibility for psychotic episodes if disturbances of blood-brain-barrier integrity occur.
Bayat, Ahmad; Burbelo, Peter D; Browne, Sarah K; Quinlivan, Mark; Martinez, Bianca; Holland, Steven M; Buvanendran, Asokumar; Kroin, Jeffrey S; Mannes, Andrew J; Breuer, Judith; Cohen, Jeffrey I; Iadarola, Michael J
The mechanisms by which varicella zoster virus (VZV) reactivation causes postherpetic neuralgia (PHN), a debilitating chronic pain condition, have not been fully elucidated. Based on previous studies identifying a causative role for anti-cytokine autoantibodies in patients with opportunistic infections, we explored this possibility in PHN. Sera from herpes zoster (HZ) patients without and with PHN (N = 115 and 83, respectively) were examined for the presence of autoantibodies against multiple cytokines, and other known autoantigens. In addition, a cohort of patients with complex regional pain syndrome or neuropathic pain was tested for autoantibodies against selected cytokines. Antibody levels against VZV, Epstein Barr virus, and herpes simplex virus-2 were also measured in the HZ and PHN patients. Patient sera with high levels of anti-cytokine autoantibodies were functionally tested for in vitro neutralizing activity. Six PHN subjects demonstrated markedly elevated levels of single, autoantibodies against interferon-α, interferon-γ, GM-CSF, or interleukin-6. In contrast, the HZ and the pain control group showed low or no autoantibodies, respectively, against these four cytokines. Further analysis revealed that one PHN patient with high levels of anti-interleukin-6 autoantibodies had a markedly depressed antibody level to VZV, potentially reflecting poor T cell immunity against VZV. In vitro functional testing revealed that three of the five anti-cytokine autoantibody positive PHN subjects had neutralizing autoantibodies against interferon-α, GM-CSF or interleukin-6. In contrast, none of the HZ patients without PHN had neutralizing autoantibodies. These results suggest the possibility that sporadic anti-cytokine autoantibodies in some subjects may cause an autoimmune immunodeficiency syndrome leading to uncontrolled VZV reactivation, nerve damage and subsequent PHN.
Heineke, Marieke H; van der Steen, Lydia P E; Korthouwer, Rianne M; Hage, J Joris; Langedijk, Johannes P M; Benschop, Joris J; Bakema, Jantine E; Slootstra, Jerry W; van Egmond, Marjolein
The cross-linking of the IgA Fc receptor (FcαRI) by IgA induces release of the chemoattractant LTB4, thereby recruiting neutrophils in a positive feedback loop. IgA autoantibodies of patients with autoimmune blistering skin diseases therefore induce massive recruitment of neutrophils, resulting in severe tissue damage. To interfere with neutrophil mobilization and reduce disease morbidity, we developed a panel of specific peptides mimicking either IgA or FcαRI sequences. CLIPS technology was used to stabilize three-dimensional structures and to increase peptides' half-life. IgA and FcαRI peptides reduced phagocytosis of IgA-coated beads, as well as IgA-induced ROS production and neutrophil migration in in vitro and ex vivo (human skin) experiments. Since topical application would be the preferential route of administration, Cetomacrogol cream containing an IgA CLIPS peptide was developed. In the presence of a skin permeation enhancer, peptides in this cream were shown to penetrate the skin, while not diffusing systemically. Finally, epitope mapping was used to discover sequences important for binding between IgA and FcαRI. In conclusion, a cream containing IgA or FcαRI peptide mimetics, which block IgA-induced neutrophil activation and migration in the skin may have therapeutic potential for patients with IgA-mediated blistering skin diseases. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Jin, Yonglong; Guan, Songlei; Liu, Linlin; Sun, Shilong; Lee, Kuang-Hui; Wei, Jun
Our recent work suggested that circulating IgG antibodies to a linear peptide derived from p16 protein were significantly increased in patients with lung cancer. The present study was then designed to test whether such autoantibodies were also altered in esophageal cancer. An enzyme-linked immunosorbent assay was developed in-house to determine circulating IgA and IgG antibodies against p16 protein-derived antigens in 97 patients with esophageal squamous cell carcinoma (ESCC) and 226 healthy subjects. The levels of anti-p16 IgG but not IgA antibodies were significantly higher in the patient group than the control group (t = 2.81, P = 0.0052); circulating anti-p16 IgG levels were inversely correlated with stages of ESCC (r = -0.30, df = 81, P = 0.0058) and patients with stage I of ESCC had the highest IgG level among all four stages (t = 5.25, P ≤ 0.0001, compared with control subjects). There was no correlation between the levels of IgA and IgG either in the patient group (r = -0.05, df = 86, P = 0.627) or in the control group (r = -0.1, df = 205, P = 0.146). Circulating IgG autoantibody to p16 protein may be a potential biomarker for early diagnosis of esophageal cancer. © 2014 Wiley Publishing Asia Pty Ltd.
Xiong, Na; Hu, Shaomin
The intestine harbors enormous numbers of commensal bacteria and is under frequent attack from food-borne pathogens and toxins. A properly regulated immune response is critical for homeostatic maintenance of commensals and for protection against infection and toxins in the intestine. IgA isotype antibodies function specifically in mucosal sites such as the intestines to help maintain intestinal health by binding to and regulating commensal microbiota, pathogens and toxins. IgA antibodies are produced by intestinal IgA antibody-secreting plasma cells generated in gut-associated lymphoid tissues from naïve B cells in response to stimulations of the intestinal bacteria and components. Research on generation, migration, and maintenance of IgA-secreting cells is important in our effort to understand the biology of IgA responses and to help better design vaccines against intestinal infections. PMID:25837997
Libbey, Jane E.; Coon, Hilary H.; Kirkman, Nikki J.; Sweeten, Thayne L.; Miller, Judith N.; Stevenson, Edward K.; Lainhart, Janet E.; McMahon, William M.; Fujinami, Robert S.
Autoantibodies to central nervous system antigens, such as myelin basic protein (MBP), may play a role in autism. We measured autoantibody titers to MBP in children with autism, both classic onset and regressive onset forms, controls (healthy age- and gender-matched) and individuals with Tourette syndrome via enzyme-linked immunosorbent assays. We…
Libbey, Jane E.; Coon, Hilary H.; Kirkman, Nikki J.; Sweeten, Thayne L.; Miller, Judith N.; Stevenson, Edward K.; Lainhart, Janet E.; McMahon, William M.; Fujinami, Robert S.
Autoantibodies to central nervous system antigens, such as myelin basic protein (MBP), may play a role in autism. We measured autoantibody titers to MBP in children with autism, both classic onset and regressive onset forms, controls (healthy age- and gender-matched) and individuals with Tourette syndrome via enzyme-linked immunosorbent assays. We…
Horiguchi, Yuji; Ikoma, Akihiko; Sakai, Rie; Masatsugu, Asako; Ohta, Miyuki; Hashimoto, Takashi
A 3-year-old boy presented with multiple vesicles, showing a rosette-like arrangement around the crusts. Histopathological and immunohistochemical examinations demonstrated subepidermal blistering with neutrophilic infiltration associated with deposition of IgA, but not IgG, linearly distributed along the basement membrane zone (BMZ) of the epidermis. Indirect immunofluorescence revealed circulating antibodies (IgA class, x160) against the BMZ of guinea pig lip skin. Based on the diagnosis of linear IgA dermatosis (LAD) of childhood, administration of dexamethasone (2 mg/day) was started, and the eruptions diminished immediately. Western blot analysis using extract of the HaCaT cell as a substrate, demonstrated the corresponding antigen at 120-kDa molecular weight. There have been 213 cases of LAD reported in Japan including conference abstracts and these were studied to determine whether infantile cases differed from adult ones, and whether cases associated with IgG as well as IgA (IgA/G type), differed from the cases associated with IgA only (IgA type). IgG contributed less frequently to the infantile type (age of onset, < or =15 years) than to the adult type (age of onset, > or =16 years). Clinical appearance did not show any obvious difference between the IgA/G type and IgA type. However, three-quarters of cases showing localization of antigen to the dermal side were the IgA/G type.
Phung-Van, P.; Abdel-Wahab, M.; Nguyen-Xuan, H.
Isogeometric analysis (IGA) based on HSDT is used to simulate buckling analysis of nanoplates. The material properties of nanoplates based on the Mori-Tanaka schemes and the rule of mixture are used. The differential nonlocal equations with size effect are utilized. The nonlocal governing equations are approximated according to IGA, that satisfies naturally the higher-order derivatives continuity requirement in weak form of nanoplates. Several numerical results are presented to demonstrate the reliability of the proposed method.
A 50-year-old woman developed pronounced IgA-deficiency and hypothyroidism after 131I treatment for Graves' disease. The deficiency state was associated with a severe sinobronchial syndrome. Treatment with L-thyroxine resulted in a normal IgA concentration and a dramatic clinical improvement. Of the various possible underlying mechanisms, impaired synthesis of IgA light and heavy light chains seemed most probable. Impaired production of J-chain was excluded. PMID:7339604
Macpherson, Andrew J; McCoy, Kathy D
IgA is induced through T-cell-dependent and -independent pathways. In this issue, Bunker et al. (2015) now show that the T-cell-independent pathway is sufficient to coat most small intestinal microbes specifically, and Fransen et al. (2015) find that IgA coating promotes uptake of microbes into Peyer's patches and drives further induction in a positive-feedback loop.
Montaño Loza, Aldo J; Angulo, Paul
Autoantibodies are a nonpathogenic manifestation of immune reactivity that may occur in acute and chronic liver diseases. Autoantibodies are the consequence rather than the cause of liver injury, and they can be used as diagnostic tools rather than etiologic markers. Conventional autoantibodies used in the categorization of liver disease are antinuclear antibodies, smooth muscle antibodies, antibodies to liver/kidney microsome type 1, antimitochondrial antibodies, and perinuclear antineutrophil cytoplasmic antibodies. However, the final diagnosis and the treatment strategies do not depend solely on the serological markers. Autoantibodies titles vary overtime and their behavior does not correlate with disease activity. Over-interpretation is the major pitfall in the clinical application of the serological results. Recognition and characterization of new autoantibodies is expected to improve the diagnostic precision, provide diagnostic parameters, and elucidate target autoantigens for the management of liver diseases.
Elvers, Karen T; Williams, Alistair J K
Epitope mapping is the process of experimentally identifying the binding sites, or "epitopes," of antibodies on their target antigens. Understanding the antibody-epitope interaction provides a basis for the rational design of potential preventative vaccines. Islet autoantibodies are currently the best available biomarkers for predicting future type 1 diabetes. These include autoantibodies to the islet beta cell proteins, insulin and the tyrosine phosphatase islet antigen-2 (IA-2) which selectively bind to a small number of dominant epitopes associated with increased risk of disease progression. The major epitope regions of insulin and IA-2 autoantibodies have been identified, but need to be mapped more precisely. In order to characterize these epitopes more accurately, this article describes the methods of cloning and mutagenesis of insulin and IA-2 and subsequent purification of the proteins that can be tested in displacement analysis and used to monitor immune responses, in vivo, to native and mutated proteins in a humanized mouse model carrying the high-risk HLA class II susceptibility haplotype DRB1*04-DQ8.
Coppo, R; Camilla, R; Amore, A; Peruzzi, L
IgA nephropathy (IgAN) is characterized by mesangial deposits of IgA1, likely due to accumulation of IgA immune complexes. The activation of intracellular signaling mostly results in oxidative stress, as detected in mesangial cells cultured with aberrantly glycosylated IgA or IgA aggregates and in renal biopsies of patients with IgAN. Signs of altered oxidation/antioxidation balance have been detected in sera and/or in erythrocytes of patients with IgAN, including increased levels of lipoperoxide or malondialdehyde and reduced activity of superoxide dismutase, catalase and glutathione peroxidase. Moreover, increased levels of a marker of oxidative stress, advanced oxidation protein products (AOPPs), have been reported to be significantly associated with proteinuria and disease progression in patients with IgAN. AOPPs are often carried by albumin and can in turn enhance the oxidative stress in the circulation. Recent research suggests that the nephrotoxicity of aberrantly glycosylated IgA1 in IgAN is enhanced in the presence of systemic signs of oxidative stress, and it is tempting to hypothesize that the level of the oxidative milieu conditions the different expression and progression of IgAN.
Shor, Dana Ben-Ami; Orbach, Hedi; Boaz, Mona; Altman, Arie; Anaya, Juan-Manuel; Bizzaro, Nicola; Tincani, Angela; Cervera, Ricard; Espinosa, Gerard; Stojanovich, Ljudmila; Rozman, Blaž; Bombardieri, Stefano; Vita, Salvatore De; Damoiseaux, Jan; Villalta, Danilo; Tonutti, Elio; Tozzoli, Renato; Barzilai, Ori; Ram, Maya; Blank, Miri; Agmon-Levin, Nancy; Shoenfeld, Yehuda
Background: Gastrointestinal (GI)-related autoantibodies (Abs) are rarely evaluated in autoimmune diseases (AID) other than inflammatory bowel disease, autoimmune hepatitis and celiac disease. Our aim was to determine the prevalence of these antibodies in a wide spectrum of AID. Methods: We examined 923 serum samples representing 18 AID and compared them with 338 samples from healthy subjects. We used the BioPlex 2200-immunoassay (Bio-Rad, USA) to test samples for the presence of IgA and IgG directed at gliadin (AGA), tissue-transglutaminase (tTG), and Saccharomyces cerevisiae (ASCA). Results: Prevalence of IgA AGA was significantly higher in antiphospholipid syndrome (APS) (7.1 %, P=0.012) and in pemphigus vulgaris (25%, P =0.008) patients, as compared with healthy controls. Presence of IgG-AGA was more common among Crohn’s disease (20.5%, P = 0.023) and rheumatoid arthritis (6.5%, P=0.027) patients. IgG anti tTG were frequently observed in APS (6.1%, P=0.012), in giant cell arteritis (11.5%, P=0.013) and in ulcerative colitis (11.1%, P=0.018) patients, and as expected, higher prevalence of ASCA (IgA 19.3% and IgG 27.7%) was found in Crohn’s disease. IgG ASCA were also found in systemic lupus erythematosus (SLE) (4.5%, P=0.01), in Graves’ disease (5.7%, P=0.018), in cryoglobulinemia (7.1%, P=0.006), and in patients with vasculitides (6.5%, P=0.002). In contrast, lower prevalence of IgG type AGA was found in SLE (P=0.034), cryoglobulinemia (P=0.019) and vasculitides (P=0.013) patients. Conclusions: Our findings suggest an association between GI-related- Abs and a wide spectrum of AID. The clinical implication of these findings is yet to be determined. PMID:23885314
Sinico, R A; Fornasieri, A; Maldifassi, P; Colasanti, G; D'Amico, G
IgA rheumatoid factor, IgA and IgG immune complexes were measured in 119 patients with IgA nephropathy. IgA rheumatoid factor was detected in 62/119 (52%) patients and in 92/265 (35%) serum samples. There was a good correlation (p less than 0.001) between the presence of IgA rheumatoid factor and the presence as well as levels of IgG immune complexes, but not between levels of IgA rheumatoid factor and other clinical or immunological parameters. However, higher levels of serum IgA were found in the subgroup of patients with constantly positive IgA rheumatoid factor. Using aggregated human IgG, we could not demonstrate antiglobulin activity in renal biopsy specimens from 36 patients. These results suggest that IgA rheumatoid factor does not play a primary role in renal damage in IgA nephropathy, but could simply reflect a response to IgG immune complexes in a disorder characterized by abnormalities of IgA production. Nevertheless, the presence of circulating IgA rheumatoid factor in a substantial proportion of patients, especially in those with features of polyclonal IgA activation, provides additional evidence for a general perturbation of IgA metabolism in this disease and could represent an antigen-specific system with which to study regulation of IgA synthesis.
Haas, M; Jafri, J; Bartosh, S M; Karp, S L; Adler, S G; Meehan, S M
Antineutrophil cytoplasmic autoantibodies (ANCA) are commonly associated with a necrotizing and crescentic glomerulonephritis (GN) that is pauci-immune, with few or no glomerular immune complex deposits detectable by immunofluorescence (IF) or electron microscopy (EM). Immunoglobulin A (IgA) nephropathy may also be manifest as a crescentic GN, but it is characterized by mesangial immune complex deposits containing IgA and is rarely associated with myeloperoxidase (MPO)- or proteinase 3 (PR3)-specific ANCA when an enzyme immunoassay is used to detect these antibodies. This report describes six patients with severe crescentic GN with mesangial IgA deposits by IF and mesangial electron-dense deposits by EM in patients with positive ANCA serological test results (four patients, anti-PR3; one patient, anti-MPO; one patient, anti-PR3 and anti-MPO). Patients presented with acute or progressive renal insufficiency, hematuria, proteinuria (nephrotic range in two patients), and hypertension. Three patients had evidence of systemic vasculitis: two patients at initial presentation and one patient later in the clinical course. Renal biopsy specimens showed crescents in greater than 50% of glomeruli in all cases, but only mild, focal and segmental mesangial and endocapillary hypercellularity, more typical of ANCA-associated crescentic GN than of crescentic IgA nephropathy without associated ANCA. Semiquantitative analysis of mesangial and endocapillary cellularity performed on renal biopsy slides from these six patients and from eight ANCA-negative patients with IgA nephropathy and crescents in greater than 50% of glomeruli showed significantly greater hypercellularity in the ANCA-negative cases. Three of five ANCA-positive patients for whom follow-up clinical data were available showed improved renal function after treatment with cyclophosphamide and corticosteroids and have not developed end-stage renal disease 17, 20, and 25 months postbiopsy. The remaining two patients were
Tezuka, Hiroyuki; Abe, Yukiko; Asano, Jumpei; Sato, Taku; Liu, Jiajia; Iwata, Makoto; Ohteki, Toshiaki
Although both conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) are present in the gut-associated lymphoid tissues (GALT), the roles of pDCs in the gut remain largely unknown. Here we show a critical role for pDCs in T cell-independent (TI) IgA production by B cells in the GALT. When pDCs of the mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) (which are representative GALT) were cultured with naive B cells to induce TI IgA class switch recombination (CSR), IgA production was substantially higher than in cocultures of these cells with cDCs. IgA production was dependent on APRIL and BAFF production by pDCs. Importantly, pDC expression of APRIL and BAFF was dependent on stromal cell-derived type I IFN signaling under steady-state conditions. Our findings provide insight into the molecular basis of pDC conditioning to induce mucosal TI IgA production, which may lead to improvements in vaccination strategies and treatment for mucosal-related disorders.
Belov, Katherine; Zenger, Kyall R; Hellman, Lars; Cooper, Desmond W
IgA is found only in birds and mammals where it is the principal immunoglobulin class found in secretions, providing protection at mucosal surfaces. The structure of IgA in birds is different from that of marsupials and eutherians. The avian heavy-chain constant region of IgA (Ca) consists of four domains, while marsupial and eutherian Ca consists of three domains plus a hinge. Here we describe the cloning and characterization of the heavy chain of IgA from the short-beaked echidna, Tachyglossus aculeatus, and report that monotreme Ca is composed of three domains plus a hinge, making it similar to its therian counterparts. The amino acid sequence identity of echidna Ca is approximately 47% with the therians and 30% with birds. Phylogenetic analysis of the Ca sequences provides strong support for the Theria hypothesis, which proposes that monotremes diverged prior to the separation of marsupial and eutherians, and directly contradicts the results of the mitochondrial data, which support a "Marsupionta" relationship which has marsupials and monotremes closer to each other. The characterization of the heavy chain of IgA from monotremes, in conjunction with the recent description of monotreme IgG and IgE nucleotide sequence, confirms that the "second big bang" of immunoglobulin evolution predated the divergence of extant mammals.
Novak, Jan; Julian, Bruce A.; Tomana, Milan; Mestecky, Jiri
Circulating immune complexes containing aberrantly glycosylated IgA1 play a pivotal role in the pathogenesis of IgAN. A portion of IgA1 secreted by IgA1-producing cells in patients with IgAN is galactose-deficient and consequently recognized by anti-glycan IgG or IgA1 antibodies. Some of the resultant immune complexes in the circulation escape normal clearance mechanisms, deposit in the renal mesangium, and induce glomerular injury. Recent studies of the origin of these aberrant molecules, their glycosylation profiles, and mechanisms of biosynthesis have provided new insight into the autoimmune nature of the pathogenesis of this common renal disease. An imbalance in the activities of the pertinent glycosyltransferases in the IgA1-producing cells favors production of molecules with galactose-deficient O-linked glycans at specific sites in the hinge region of the alpha heavy chains. Using sophisticated analytical methods, it may be possible to define biomarkers for diagnostic purposes and identify new therapeutic targets for a future disease-specific therapy. PMID:18222349
Sokol, R J; Booker, D J; Stamps, R
AIMS--To examine a large series of patients in whom both red cell autoantibodies and carcinoma are present; and to determine whether this rare occurrence is a true association or a chance event. METHODS--The laboratory records of 160 patients (76 men, 84 women; mean age 68 years) with erythrocyte autoantibodies and confirmed carcinoma were examined for site of tumour origin and clinical and immunohematological findings. To test whether the concomitant occurrence of autoantibodies and carcinoma was fortuitous, data on total population and carcinoma incidence were included in a chi 2 analysis. RESULTS--The association was significant (chi 2 = 97.5, p < 0.0005); erythrocyte autoantibodies and carcinoma were found together 12-13 times more often than expected from their relative frequencies. Autoantibodies occurred with a variety of carcinomas, particularly those of breast, lung, colon, rectum, and prostate; this largely reflected tumour incidence. Adenocarcinoma, squamous, anaplastic, and transitional cell types were all represented. Warm, cold, and mixed autoantibodies were not associated with particular tumour sites or histology. Eighty six patients had haemolysis of varying severity, 37 had metastatic disease, and 28 died within a few months of presentation. CONCLUSIONS--The presence of erythrocyte autoantibodies and carcinoma in the same patient is a true association and probably reflects a fundamental disturbance in immune homeostasis. It tends to occur with a large tumour mass and metastatic disease, and generally indicates a poor prognosis. PMID:8027372
Usha; Singh, Gyanendra; Agrawal, Neeraj Kumar; Singh, Rana Gopal; Kumar, Shashi Bhushan
Introduction Type I diabetes Mellitus (T1DM) is caused by autoimmune destruction of β-cells of pancreas. Two forms of T1DM are known called as 1A (autoimmune) and 1B (idiopathic). Aim Aim was to study the prevalence of Anti-TTG IgA, Anti-TPO, GADA, ZnT8 and IA-2 autoantibodies and HLA DR and DQ genes and its diagnostic value in T1DM. Materials and Methods Thirty four T1DM patients, 59 type 2 diabetes mellitus (T2DM) patients and 28 healthy controls were included in study. Antibodies levels were estimated by ELISA and HLA typing was performed by SSP-PCR method. Result The prevalence of various autoantibodies in T1DM were Anti-TTG 14.7%, Anti-TPO 17.65%, GADA 38.23%, ZnT8 11.76% and IA-2 5.88%. Only GADA and ZnT8 were significantly positive in T1DM. GADA (66.67%) and ZnT8 (33.33%) positivity was more in patients below 15 years age while levels of other antibodies were higher after 15 years age. All autoantibodies were detected in higher frequency in T1DM than in T2DM and controls. HLA DR and DQ typing showed highly significant increase in DRB1*0301 (61.76%, p=0.00) and DQB1*0201 (64.71%, p=0.00) in T1DM. Subjects with HLA DRB1*0301 and DQB1*0201 had 80-100% positive prevalence of GADA, ZnT8, IA-2, Anti-TTG and Anti-TPO autoantibodies. Conclusion Combination of GADA antibody with DRB1 and DQB1 estimation improved diagnosis of T1A than insulin antigen specific antibodies alone. PMID:27630850
Gunawardena, H; Wedderburn, L R; Chinoy, H; Betteridge, Z E; North, J; Ollier, W E R; Cooper, R G; Oddis, C V; Ramanan, A V; Davidson, J E; McHugh, N J
Objective The identification of novel autoantibodies in juvenile dermatomyositis (DM) may have etiologic and clinical implications. The aim of this study was to describe autoantibodies to a 140-kd protein in children recruited to the Juvenile DM National Registry and Repository for UK and Ireland. Methods Clinical data and sera were collected from children with juvenile myositis. Sera that recognized a 140-kd protein by immunoprecipitation were identified. The identity of the p140 autoantigen was investigated by immunoprecipitation/immunodepletion, using commercial monoclonal antibodies to NXP-2, reference anti-p140, and anti-p155/140, the other autoantibody recently described in juvenile DM. DNA samples from 100 Caucasian children with myositis were genotyped for HLA class II haplotype associations and compared with those from 864 randomly selected UK Caucasian control subjects. Results Sera from 37 (23%) of 162 patients with juvenile myositis were positive for anti-p140 autoantibodies, which were detected exclusively in patients with juvenile DM and not in patients with juvenile DM–overlap syndrome or control subjects. No anti-p140 antibody–positive patients were positive for other recognized autoantibodies. Immunodepletion suggested that the identity of p140 was consistent with NXP-2 (the previously identified MJ autoantigen). In children with anti-p140 antibodies, the association with calcinosis was significant compared with the rest of the cohort (corrected P < 0.005, odds ratio 7.0, 95% confidence interval 3.0–16.1). The clinical features of patients with anti-p140 autoantibodies were different from those of children with anti-p155/140 autoantibodies. The presence of HLA–DRB1*08 was a possible risk factor for anti-p140 autoantibody positivity. Conclusion This study has established that anti-p140 autoantibodies represent a major autoantibody subset in juvenile DM. This specificity may identify a further immunogenetic and clinical phenotype within the
Self, Sally E
The proper use and interpretation of serologic testing for diagnosing autoimmune diseases presents a challenge to clinicians for several reasons. Most laboratory tests for autoimmune disease are significantly less than 100% sensitive or specific. In addition, different techniques for the same antibody test may give different results, such as indirect immunofluorescence and multiplex bead assay for antinuclear antibody. Autoantibody testing should only be performed in the context of the clinical workup of patients who have a reasonable likelihood of having the disease for which the testing is relevant. Otherwise, the predictive value of a positive test is too low. Particularly with antinuclear antibody and antineutrophil cytoplasmic antibody testing, clinicians must know the methodology through which the tests are being performed, and should develop a relationship with the laboratory pathologist so that inconsistent or surprising results can be investigated.
Marinaki, M; Benini, D; Fasoli, E; Fanos, V
IgA nephropathy is a primitive cronic idiopatic glomerulonephritis, characterized by diffuse depositis of IgA in the glomeruler mesangium. Familial cases are also descripted. IgA nephropaty is more frequent in males and in white rase. In Italy it's the most frequently recognized glomerulonephritis in renal biopsia (20%), especially in patients with dismorfic micro or macroematuria and nephrotic proteinuria. Clinical presentation is often in association with respiratory tract or gastrointestinal disorders. The most relevant pathogenetic hypothesis suggest an IgA abnormal glycosilation, with mesangial IgA aggregation, increased mesangial reactivity and release of inflammatory mediators and fibrotic agents. Treatment is considered in rapidly progressing forms. At the present, there is no treatment of proven value in all patients, althoug interesting results have been published with prednison, ACE-inhibitors or fish-oil in decresing renal deterioration rate. Natural history varies in different series. Renal survival at 10 years is 85% in Italy, 94% in France, 97% in the USA. Poor prognostic factor are heavy proteinuria and hypertension. However a wide inter-individual variability is observed.
Planer, Joseph D.; Peng, Yangqing; Kau, Andrew L.; Blanton, Laura V.; Ndao, I. Malick; Tarr, Phillip I.; Warner, Barbara B.; Gordon, Jeffrey I.
Immunoglobulin A (IgA), the major class of antibody secreted by the gut mucosa, is an important contributor to gut barrier function1–3. The repertoire of IgA bound to gut bacteria reflects both T cell-dependent and -independent pathways4,5, plus glycans present on the antibody’s secretory component6. Human gut bacterial taxa targeted by IgA in the setting of intestinal barrier dysfunction are capable of producing intestinal pathology when isolated and transferred to gnotobiotic mice7,8. A complex reorientation of gut immunity occurs as infants transition from passively acquired IgA present in breast milk to host-derived IgA9–11. How IgA responses co-develop with assembly of the microbiota during this period remains poorly understood. Here, we (i) identify a set of age-discriminatory bacterial taxa whose representations define a program of microbiota assembly/maturation during the first 2 postnatal years that is shared across 40 healthy USA twin pairs; (ii) describe a pattern of progression of gut mucosal IgA responses to bacterial members of the microbiota that is highly distinctive for family members (twin pairs) during the first several postnatal months then generalizes across pairs in the second year; and (iii) assess the effects of zygosity, birth mode and breast feeding. Age-associated differences in these IgA responses can be recapitulated in young germ-free mice, colonized with fecal microbiota obtained from two twin pairs at 6 and 18 months of age, and fed a sequence of human diets that simulate the transition from milk feeding to complementary foods. The majority of these responses were robust to diet suggesting that ‘intrinsic’ properties of community members play a dominant role in dictating IgA responses. The approach described can be used to define gut mucosal immune development in health and disease states and help discover ways for repairing or preventing perturbations in this facet of host immunity. PMID:27279225
Martínez-Flores, José A; Serrano, Manuel; Pérez, Dolores; Lora, David; Paz-Artal, Estela; Morales, José M; Serrano, Antonio
Patients with antiphospholipid syndrome (APS) have a hypercoagulable condition associated with the presence of antiphospholipid autoantibodies (aPL). Consensus antibodies for diagnosis are lupus anticoagulant, anti-beta2 glycoprotein I (B2GPI) and anticardiolipin (IgG or IgM). Circulating immunocomplexes (CIC) of B2GPI associated with IgM or IgG were reported. Isolated IgA aB2GPI antibodies have achieved high diagnostic value although specific CIC of B2GPI bounded to IgA (B2A-CIC) has still not been described. CIC detection assays are mainly based on interaction with complement and are not appropriate to detect B2A-CIC because IgA does not fix complement using the classical pathway. Sera from healthy blood donors (N= 247) and from patients with thrombosis background and isolate positive for IgA aB2GPI (N = 68) were studied in a case-control study. Two methods were applied, these being a capture ELISA to quantify specific B2A-CIC and quantification of total IgA anti-B2GPI after dissociating CIC. B2A-CIC values in APS-patients were 19.27 ± 2.6 AU vs 6.1 ± 0.4 AU in blood donors (p < 0.001). There were 36.4% B2A-CIC positive patients (cutoff 21 AU) versus 5.5% in blood donors (p < 0.001). Dissociated IgA aB2GPI levels (total IgA aB2GPI) were 146.8 ± 10.8 IU/mL in patients vs. 22.4 IU/mL in controls (p < 0.001). B2A-CIC was independent of B2GPI and autoantibodies IgA aB2GPI serum levels. B2A-CIC can be identified and quantified in an easy and reproducible manner using two complement-independent methods. The use of these tests in prospective studies will allow better understanding of the prognosis and outcome of patients. Copyright © 2015 Elsevier B.V. All rights reserved.
Sategna-Guidetti, C; Ferfoglia, G; Bruno, M; Pulitano, R; Roccatello, D; Amore, A; Coppo, R
The finding in primary IgA nephropathy of increased levels of IgA to food antigens and particularly to gliadin prompted the hypothesis that a subgroup of these patients may have latent coeliac disease. The observation that gliadin may experimentally induce IgA mesangial deposits supported this hypothesis. We evaluated specific immunological markers of coeliac disease (antiendomysium antibodies) which parallel histological changes of gluten sensitive enteropathy, and an IgA immunofluorescent test for antigliadin antibodies in 18 patients with IgA nephropathy, in 56 untreated coeliac disease patients, in 254 controls (58 healthy and 196 disease controls). Antiendomysium antibodies were positive in 89.28% of coeliac patients, but negative in all IgA nephropathies and controls. IgA immunofluorescent test for antigliadin antibodies, negative in all IgA nephropathy patients, was positive in 76.78% of coeliac patients and in 4.91% of controls. ELISA IgA antigliadin antibodies were negative in controls, but positive in 22.22% of IgA nephropathy patients and in 60.71% of coeliac patients. Our data would suggest that in most patients with IgA nephropathy there is no evidence of latent coeliac disease. PMID:1582590
Hegazy, Salama; Bouchouicha, Sana; Khaled, Aida; Laadher, Lilia; Sellami, Maryem Kallel; Zeglaoui, Faten
Background IgA pemphigus is a rare autoimmune vesiculo-pustular skin disease. Only approximately 70 cases have been reported to date. We report a case of IgA pemphigus with IgA antibodies to desmoglein 1 (Dsg1) and desmoglein 3 (Dsg3). Case report We report the case of an 60-year-old man with intraepidermal neutrophilic IgA pemphigus with IgA antibodies to Dsg1 and Dsg3. Histologic examination revealed subcorneal neutrophilic pustules with few acantholytic cells. The disease was not effectively controlled by conventional therapeutic regimens (colchicine, dapsone). Systemic treatment with isotretinoin 25 mg/d and prednisone 20 mg/d achieved only a slight effect after six months. Conclusions Our case confirmed the recalcitrant nature of IgA pemphigus in response to distinct therapies, indicating that further research focusing on therapeutic approaches for this type of pemphigus is needed. Physicians should keep IgA pemphigus in mind when approaching patients with bullous eruption. PMID:27867744
Hegazy, Salama; Bouchouicha, Sana; Khaled, Aida; Laadher, Lilia; Sellami, Maryem Kallel; Zeglaoui, Faten
IgA pemphigus is a rare autoimmune vesiculo-pustular skin disease. Only approximately 70 cases have been reported to date. We report a case of IgA pemphigus with IgA antibodies to desmoglein 1 (Dsg1) and desmoglein 3 (Dsg3). We report the case of an 60-year-old man with intraepidermal neutrophilic IgA pemphigus with IgA antibodies to Dsg1 and Dsg3. Histologic examination revealed subcorneal neutrophilic pustules with few acantholytic cells. The disease was not effectively controlled by conventional therapeutic regimens (colchicine, dapsone). Systemic treatment with isotretinoin 25 mg/d and prednisone 20 mg/d achieved only a slight effect after six months. Our case confirmed the recalcitrant nature of IgA pemphigus in response to distinct therapies, indicating that further research focusing on therapeutic approaches for this type of pemphigus is needed. Physicians should keep IgA pemphigus in mind when approaching patients with bullous eruption.
Trascasa, M L; Egido, J; Sancho, J; Hernando, L
Eleven out of 15 patients with IgA mesangial glomerulonephritis (Berger's disease) had an increased proportion of serum IgA in 9-21S fractions on 5-40% sucrose density-gradient ultracentrifugation; the heavier fractions decreased at acid pH. Serum IgA purified by starch electrophoresis was subjected to reduction-alkylation yielding fragments of lower molecular weight. J chain was detected on urea alkaline polyacrylamide electrophoresis and the high-molecular weight IgA bound the human secretory component. In six patients treated with phenytoin for 1 year there was a decrease in polymeric IgA and an increase in monomeric IgA adopting a pattern similar to that of the controls. Our results show the presence of a large amount of true IgA polymers, partially as immune complexes, in the serum of patients with Berger's disease. These data together with their normalization after phenytoin treatment may open a new pathogenic and therapeutic approach to this entity.
Altay, Mustafa; Secilmis, Sema; Unverdi, Selman; Ceri, Mevlut; Duranay, Murat
Although Behçet's disease (BD) is a kind of systemic disease, renal involvement is rare, especially IgA nephropathy (IgAN). Renal manifestations in BD range from mild urinary abnormalities to glomerulonephritis with persistent renal failure, which includes minimal change disease, proliferative glomerulonephritis, rapidly crescentic glomerulonephritis, renal amyloidosis and IgA nephropathy. Amyloidosis seems to be the most common type of renal lesion in BD, and several cases of nephrotic syndrome secondary to amyloidosis have been documented. Co-occurrence of BD and IgA nephropathy has only been reported in only few cases. We describe two patients with the rare association of BD and IgAN. We suggested that it is important to periodically perform renal function assessment in patients with BD, through urinalysis and measurement of serum creatinine for detecting any abnormality and providing an early adequate treatment.
Hwang, S-J; Chu, C-W; Huang, D-F; Lan, K-H; Chang, F-Y; Lee, S-D
Chronic hepatitis C virus (HCV) infection may induce immunological disorders in the host such as the presence of cryoglobulinemia or serum autoantibodies. The pathogenesis of these phenomena remains unclear but may reflect the host's genetic predispositions. The aim of this study was to evaluate the association between these immunological manifestations and human leukocyte antigen (HLA) expression in Chinese patients with chronic hepatitis C. The presence of serum cryoglobulin and autoantibodies (antinuclear antibody, antismooth muscle antibody, antimitochondrial antibody, antiliver-kidney-microsomal antibody) was determined in 122 Chinese patients with chronic hepatitis C. HLA class I and class II antigens were measured by microlymphocytotoxicity assay or by DNA typing in 122 chronic hepatitis C patients and 228 healthy controls. Of the 122 patients with chronic hepatitis C, 52 (43%) had cryoglobulinemia and 48 (39%) had serum autoantibodies. A significant difference in HLA frequency was noted for DR3, which was found in 36.5% of patients with cryoglobulinemia compared with 8.6% of patients without cryoglobulinemia and 11.3% of healthy controls. A significant difference in HLA frequency was also noted for DR4, which was found in 45.8% of patients with serum autoantibodies compared with 17.6% of patients without serum autoantibodies and 19% of healthy controls. Our results suggest the existence of HLA-linked susceptibility genes (DR3 or DR4) for the development of cryoglobulinemia or serum autoantibodies in Chinese patients with chronic hepatitis C.
Kayser, Cristiane; Fritzler, Marvin J.
Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular abnormalities, and cutaneous and visceral fibrosis. Serum autoantibodies directed to multiple intracellular antigens are present in more than 95% of patients and are considered a hallmark of SSc. They are helpful biomarkers for the early diagnosis of SSc and are associated with distinctive clinical manifestations. With the advent of more sensitive, multiplexed immunoassays, new and old questions about the relevance of autoantibodies in SSc are emerging. In this review, we discuss the clinical relevance of autoantibodies in SSc emphasizing the more recently published data. Moreover, we will summarize recent advances regarding the stability of SSc autoantibodies over the course of disease, whether they are mutually exclusive and their potential roles in the disease pathogenesis. PMID:25926833
Lindström, P; Wager, O
ELISA was applied for analysis of the HSA-human IgG autoantibody system responsible for the immunoelectrophoretic 'Tailing Albumin' (TA) phenomenon induced in most of the TA patients by prolonged nitrofurantoin therapy. Both hyperimmune porcine anti-HSA and autoimmune human anti-HSA antibodies of the IgG class were detectable by ELISA. The presence of autologous or added HSA had some inhibitory effect upon the detectability of the anti-HSA antibodies. Partial elimination of the autologous HSA by sucrose gradient ultracentrifugation or salt precipitation increased or unmasked the anti-HSA activity of some TA sera. The sensitivity of the ELISA as detector of the anti-HSA autoantibodies of whole human sera was roughly equal to that of the immunoelectrophoretic TA phenomenon. The analogy of the anti-HSA autoantibodies and the rheumatoid factors and the theoretical interest of both of them is stressed.
Berntson, Lillemor; Nordal, Ellen; Fasth, Anders; Aalto, Kristiina; Herlin, Troels; Nielsen, Susan; Rygg, Marite; Zak, Marek; Rönnelid, Johan
Early appearance of antibodies specific for native human type II collagen (anti-CII) characterizes an early inflammatory and destructive phenotype in adults with rheumatoid arthritis (RA). The objective of this study was to investigate the occurrence of anti-CII, IgM RF, IgA RF and anti-CCP in serum samples obtained early after diagnosis, and to relate the occurrence of autoantibodies to outcome after eight years of disease in children with juvenile idiopathic arthritis (JIA). The Nordic JIA database prospectively included JIA patients followed for eight years with data on remission and joint damage. From this database, serum samples collected from 192 patients, at a median of four months after disease onset, were analysed for IgG anti-CII, IgM RF, IgA RF and IgG anti-CCP. Joint damage was assessed based on Juvenile Arthritis Damage Index for Articular damage (JADI-A), a validated clinical instrument for joint damage. Elevated serum levels of anti-CII occurred in 3.1%, IgM RF in 3.6%, IgA RF in 3.1% and anti-CCP in 2.6% of the patients. Occurrence of RF and anti-CCP did to some extent overlap, but rarely with anti-CII. The polyarticular and oligoarticular extended categories were overrepresented in patients with two or more autoantibodies. Anti-CII occurred in younger children, usually without overlap with the other autoantibodies and was associated with high levels of C-reactive protein (CRP) early in the disease course. All four autoantibodies were significantly associated with joint damage, but not with active disease at the eight-year follow up. Anti-CII, anti-CCP, IgA RF and IgM RF detected early in the disease course predicted joint damage when assessed after eight years of disease. The role of anti-CII in JIA should be further studied.
Nagae, Hiroshi; Tsuchimoto, Akihiro; Tsuruya, Kazuhiko; Kawahara, Shota; Shimomura, Yukiko; Noguchi, Hideko; Masutani, Kosuke; Katafuchi, Ritsuko; Kitazono, Takanari
Clinicopathological significance of monoclonal IgA deposition and its relation to bone marrow abnormalities in IgA nephropathy (IgAN) remains unclear. We retrospectively investigated the prevalence and clinicopathological significance of monoclonal IgA deposition in 65 patients with IgAN. Serum-free light chain ratio, and urinary Bence Jones protein were also measured. Thirty-nine percent of patients were men, median age was 40 and median observation period was 31 months. Five patients (Group M) showed monoclonal IgA lambda deposition and one showed monoclonal IgA kappa deposition. Fifty-nine patients (Group P) showed polyclonal IgA deposition. There were no significant differences in the degree of proteinuria, hematuria and renal function between Group M and Group P. Total protein and albumin were significantly lower in Group M than in Group P. According to the Oxford classification, the percentage of patients with M1 was significantly higher in Group M than in Group P. One patient in Group P showed serum monoclonal IgG lambda. No patient showed abnormal serum-free light chain ratio. Seventy-five percent in Group M and 42 % in Group P were treated with steroid. Three patients in Group P progressed to end-stage renal disease (ESRD). The frequency of disappearance of proteinuria or hematuria and progression to ESRD was not different between the groups. The prevalence of monoclonal IgA deposition was 9.2 %. Although some parameters differed between the groups, renal outcome were similar. Thus, IgAN with monoclonal IgA deposition seems not to be different entity from those with polyclonal IgA deposition.
Tsirogianni, Alexandra; Pipi, Elena; Soufleros, Kostantinos
The first component of the classical pathway of the complement system (C1q) is considered to have a crucial role in the clearance of immune complexes (ICs) as well as in the removal of waste material originating from apoptotic cells. A prolonged exposure of C1q epitopes to the immune system could eventually lead to an autoimmune response against itself. Although autoantibodies against C1q are found in several diseases, their clinical interest originates from their strong association to active lupus nephritis (LN). Several studies indicate that anti-C1q autoantibodies could serve as a reliable serologic marker in the assessment of LN activity compared to other immunological tests. Additionally, it was suggested that anti-C1q autoantibodies could play a role in LN pathogenesis. Their potential pathogenic actions likely depend on genetic background, titers, Ig classes and subclasses, and specific epitopes of anti-C1q autoantibodies as well as C1q availability and allocation. It is still unclear which different types of anti-C1q autoantibodies dominate in each case and if their upregulation is pathogenic, an epiphenomenon of aberrant tissue damage, or compensatory to an uncontrolled immune response.
Lorette, Gérard; Georgesco, Gabriella
The linear IgA bullous dermatosis can have various aspects involving erythema and bullous lesions. It is a rare disease. Two peaks of frequency are noticed in children before puberty and in adults around 60 years of age. The histological and immunological characterisation is infraepidermal bullous lesions and linear deposits of IgA along the dermoepidermal basement membrane. There are some targets antigens. There is often a medical condition that seems to trigger. The link with drugs in particular with vancomycin was established. The mainstay of treatment is dapsone generally associated with steroids.
Fujimoto, Manabu; Watanabe, Rei; Ishitsuka, Yosuke; Okiyama, Naoko
In dermatomyositis, disease-specific autoantibodies now cover more than 70% of patients. These autoantibodies closely correlate with distinct clinical manifestations. In the past few years, extensive evidence has been accumulated on clinical significance of dermatomyositis-specific autoantibodies including autoantibodies against melanoma differentiation antigen 5 (MDA5), transcriptional intermediary factor 1 (TIF1), nuclear matrix protein 2 (NXP2), and small ubiquitin-like modifier activating enzyme (SAE). Anti-MDA5 antibodies are found with high specificity in clinically amyopathic dermatomyositis presenting rapidly progressive interstitial lung disease (ILD) especially in Asian population. Similar tendency has been reported in the US/Europe, although the frequency of positivity and the type of ILD may differ. Anti-TIF1 antibodies are present in juvenile and adult dermatomyositis patients with close correlation with malignancy in adult population. Anti-NXP2 antibodies share similar phenotype with anti-TIF1 antibodies, except that anti-NXP2 antibodies are associated with calcinosis and severe muscle disease. Although numbers are still small, patients with anti-SAE antibodies tend to present skin disease first and then progress to muscle weakness with systematic symptoms including dysphagia. Moreover, distinct cutaneous manifestations and muscle histopathology findings for each autoantibody have been reported. 'Autoantibody-based classification' of dermatomyositis subsets is now a useful strategy for comprehending the heterogeneous spectrum of dermatomyositis.
Koskinen, Outi; Villanen, Mikko; Korponay-Szabo, Ilma; Lindfors, Katri; Mäki, Markku; Kaukinen, Katri
A gluten-free diet omitting wheat, rye, and barley is the only effective treatment for coeliac disease. The necessity of excluding oats from the diet has remained controversial. We studied the toxicity of oats in children with coeliac disease during a 2-year follow-up by investigating jejunal transglutaminase 2 (TG2)-targeted IgA-class autoantibody deposits, a potentially more sensitive disease marker than serum antibodies or conventional histology. Twenty-three coeliac children in remission were randomized to undergo oat or gluten challenge with wheat, rye, barley, and oats. When jejunal histological relapse was evident after gluten challenge, patients excluded wheat, rye, and barley but continued with oats. Mucosal morphology and TG2-targeted autoantibody deposits were studied in jejunal biopsies taken at baseline and after 6 and 24 months. Furthermore, serum IgA-class TG2 antibodies were measured. At baseline, serum TG2 antibodies were negative in all 23 patients, but 7 of them had minor mucosal deposits. In the oats group, there was no significant change in the intensity of the deposits within 2 years. In contrast, during the gluten challenge, the intensity of the deposits clearly increased and decreased again when wheat, rye, and barley were excluded but consumption of oats was continued; this was in line with serum autoantibodies. The intensity of the mucosal deposits correlated well with both villous morphology and serum autoantibody levels. Consumption of oats does not induce TG2 autoantibody production at mucosal level in children with coeliac disease. Measurement of small-intestinal mucosal autoantibody deposits is suitable for monitoring treatment in coeliac patients.
Alshomar, Ahmad A
Nephrotic syndrome is a rare presentation of IgA nephropathy. The degree of proteinuria in IgA nephropathy predicts poor prognosis. We herein report a teenager with IGA nephropathy, the nephrotic syndrome and segmental glomerular scars who after developing complications from high dose corticosteroid therapy was successfully treated with tacrolimus and low dose prednisone. PMID:27610069
Vernersson, M; Belov, K; Aveskogh, M; Hellman, L
To trace the emergence of modern IgA isotypes during vertebrate evolution we have studied the immunoglobulin repertoire of a model monotreme, the platypus. Two highly divergent IgA-like isotypes (IgA1 and IgA2) were identified and their primary structures were determined from full-length cDNAs. A comparative analysis of the amino acid sequences for IgA from various animal species showed that the two platypus IgA isotypes form a branch clearly separated from their eutherian (placental) counterparts. However, they still conform to the general structure of eutherian IgA, with a hinge region and three constant domains. This indicates that the deletion of the second domain and the formation of a hinge region in IgA did occur very early during mammalian evolution, more than 166 million years ago. The two IgA isotypes in platypus differ in primary structure and appear to have arisen from a very early gene duplication, possibly preceding the metatherian eutherian split. Interestingly, one of these isotypes, IgA1, appears to be expressed in only the platypus, but is present in the echidna based on Southern blot analysis. The platypus may require a more effective mucosal immunity, with two highly divergent IgA forms, than the terrestrial echidna, due to its lifestyle, where it is exposed to pathogens both on land and in the water.
Sinclair, D; Saas, M; Turk, A; Goble, M; Kerr, D
Background Screening for IgA deficiency in patients with coeliac disease is essential because of the increased incidence of IgA deficiency associated with the disease, which usually relies on the estimation of IgA levels in each case. Aim To devise a method of excluding IgA deficiency without measuring total serum IgA in each case. Materials and methods The optical density readings on enzyme‐linked immunosorbent assay (ELISA) of 608 routine samples received for tissue transglutaminase (TTG) antibody testing for coeliac disease were compared with their total IgA concentrations. Dilution experiments were also carried out to ensure linear relationships between optical density on ELISA and IgA concentrations and to compare the sensitivities for TTG and endomysium antibodies in TTG‐positive samples. Results and discussion A clear relationship was shown between total IgA concentration and TTG optical density readings by ELISA. To ensure a positive TTG result if antibodies are present, it was possible to recommend an optical density level above which all samples have sufficient IgA. Samples with optical density <0.05 should be investigated further by estimating total IgA and, if low, samples should be subjected to immunofluorescence microscopy testing for IgA and IgG endomysium antibodies. Conclusions An easier, more cost‐effective and practical way of excluding IgA deficiency in the investigation on coeliac disease is reported. PMID:16489174
... Possible Complications Autoimmune disorders such as rheumatoid arthritis , systemic lupus erythematosus , and celiac sprue may develop. People with IgA ... More Autoimmune disorders Autosomal dominant Respiratory Rheumatoid arthritis Systemic lupus erythematosus Review Date 3/20/2016 Updated by: Stuart ...
Reichelt, K. L.; Skjeldal, O.
The level of IgA antibodies to gluten and gliadin proteins found in grains and to casein found in milk, as well as the level of IgG to gluten and gliadin, have been examined in 23 girls with Rett syndrome and 53 controls. Highly statistically significant increases were found for the Rett population compared to the controls. The reason for this…
Reichelt, K. L.; Skjeldal, O.
The level of IgA antibodies to gluten and gliadin proteins found in grains and to casein found in milk, as well as the level of IgG to gluten and gliadin, have been examined in 23 girls with Rett syndrome and 53 controls. Highly statistically significant increases were found for the Rett population compared to the controls. The reason for this…
Weicker, J; Underdown, B J
Human secretory component (SC) was isolated from colostral whey, and the binding of 125I-SC to purified IgA and IgM monoclonal proteins was studied using two methods to separate free from immunoglobulin-bound 125I-SC: a) gel filtration on Sephadex G-200, and b) precipitation of 125I-SC-Ig complexes with anti-Ig antibody. Both IgA dimeric proteins and IgM pentamers bound 125I-SC with approximately one SC-binding site per mole of polymer and similar affinity. Assuming a reversible equilibrium, an apparent association constant congruent to 10-8 M-1 was calculated to govern the binding of 125I-SC to immunoglobulin polymers. The assignment of a single association constant may be an oversimplication, particularly for the case of IgA polymers, since evidence was obtained that disulfide bonds were formed in the 125I-SC-IgA complex. Despite the complexity of the reaction, binding of 125I-SC to both IgA and IgM polymers could be analyzed by standard methods of saturation analysis, and both were shown to have a similar affinity for 125I-SC. No differences were noted in the affinity of 125I-SC binding to the IgA1 and IgA2 subclasses. Binding of monomeric IgA and IgM proteins could not be measured and was at least 100-fold lower than that found for IgA and IgM polymers. Complexes of 125I-SC with IgA dimers were presumed to involve covalent bond formation, since these complexes did not dissociate in guanidine-HCl. One IgA2 trimer did not form a covalent bond since it was completely dissociated in guanidine. In contrast, 125I-SC-IgM complexes were dissociated in denaturing solvent, indicating that such complexes were held together primarily by non-covalent bonds. Experiments with (Fc)5 mu isolated by high temperature tryptic digestion of IgM showed that binding of 125I-SC was to the Fc region of IgM proteins. It was suggested that the binding of SC with similar affinity to both IgA and IgM polymers may be important in the biologic function of both these immunoglobulin classes.
Liberal, Rodrigo; Mieli-Vergani, Giorgina; Vergani, Diego
The accurate diagnosis and classification of autoimmune hepatitis (AIH) rely upon the detection of characteristic autoantibodies. Positivity for anti-nuclear (ANA) and/or anti-smooth muscle (SMA) autoantibodies defines AIH type 1 (AIH-1), whereas anti-liver kidney microsomal type 1 (anti-LKM1) and/or anti-liver cytosol type 1 (anti-LC1) define AIH type 2 (AIH-2). ANA and SMA, and less commonly anti-LKM1, have also been detected in de-novo autoimmune hepatitis developing after liver transplantation, a condition that may affect patients transplanted for non-autoimmune liver disease. The diagnostic autoantibodies associated with AIH-1 are also detected in the paediatric AIH/sclerosing cholangitis overlap syndrome, referred to as autoimmune sclerosing cholangitis (ASC). ASC, like adult primary sclerosing cholangitis, is often associated with atypical perinuclear anti-neutrophil cytoplasmic autoantibodies (p-ANCA), although p-ANCA are also detected in other autoimmune liver diseases. These associations highlight the necessity for simple and prompt diagnostic autoantibody testing, and the requirement for the accurate interpretation of the results of the tests in the clinical context. Fine-mapping of antigenic autoantibody targets has facilitated the development of rapid molecular assays that have the potential to revolutionise the field if properly standardised and when used in combination with classical immunofluorescence. Despite their diagnostic significance, the pathogenic role of the various autoantibodies and the mechanisms by which they can potentially inflict damage onto the liver cell remain a topic for further research.
Gatselis, Nikolaos K; Zachou, Kalliopi; Norman, Gary L; Tzellas, George; Speletas, Matthaios; Gabeta, Stella; Germenis, Anastasios; Koukoulis, George K; Dalekos, George N
IgA antibodies against tissue-transglutaminase (anti-tTG-IgA) and IgA and IgG antibodies against deamidated gliadin peptides (anti-DGP-IgA and anti-DGP-IgG) are considered specific for celiac disease (CD) whereas, patients with chronic liver disorders have an increased risk of latent CD development. We investigated the prevalence and clinical significance of anti-DGP-IgA, anti-DGP-IgG and anti-tTG-IgA in a large cohort of patients with chronic liver diseases. 668 patients without gastrointestinal symptoms (426 viral hepatitis, 94 autoimmune liver diseases, 61 alcoholic disease, 46 non-alcoholic fatty liver disease, 41 with other liver disorders) were investigated by ELISAs (INOVA Diagnostics). Patients positive for at least one autoantibody invited for a small-intestinal biopsy and HLA-DQ typing. Anti-DGP-IgA were detected in 8.5%, anti-DGP-IgG in only one (0.15%, P<0.001) and anti-tTG-IgA in 5.8% of patients (P=0.05). Fifty-two were anti-DGP-IgA(+)/anti-tTG-IgA(-), 34 anti-DGP-IgA(-)/anti-tTG-IgA(+), and 5 anti-DGP-IgA(+)/anti-tTG-IgA(+). Anti-DGP-IgA positivity was associated with older age (P<0.05), cirrhosis (P<0.05) and increased IgA (P<0.05) whereas, anti-tTG-IgA only with cirrhosis (P<0.05). Histology and HLA-typing compatible with CD was revealed in 4/14 anti-DGP-IgA(+)/anti-tTG-IgA(-), 0/13 anti-DGP-IgA(-)/anti-tTG-IgA(+) and 2/2 anti-DGP-IgA(+)/anti-tTG-IgA(+). All 6 patients diagnosed with CD were anti-DGP-IgA(+) and only 2 anti-tTG-IgA(+). Although a significant number of patients had detectable CD-related autoantibodies, anti-DGP-IgA test seems better than anti-tTG-IgA for unmasking occult forms of CD in patients with chronic liver disorders. The known good performance for CD diagnosis of anti-DGP-IgG test was not confirmed in this specific group of patients. Copyright © 2012 Elsevier B.V. All rights reserved.
Immunoglobulin A (IgA) is the most abundantly produced immunoglobulin found primarily on mucosal surfaces. The generation of IgA and its involvement in mucosal immune responses have been intensely studied over the past years. IgA can be generated in T cell-dependent and T cell-independent pathways, and it has an important impact on maintaining homeostasis within the mucosal immune system. There is good evidence that B-1 cells contribute substantially to the production of mucosal IgA and thus play an important role in regulating commensal microbiota. However, whether B-1 cells produce antigen-specific or only nonspecific IgA remains to be determined. This review will discuss what is currently known about IgA production by B-1 cells and the functional relevance of B-1 cell-derived IgA both in vitro and in vivo. © 2015 New York Academy of Sciences.
Das, Uttara; Dakshinamurty, Kaligotla Venkata; Prayaga, Aruna; Uppin, Megha
Immunoglobulin A (IgA) nephropathy (IgAN) is the most common biopsy-proven primary glomerular disease in the world and a major contributor to the worldwide burden of endstage renal failure, with a wide geographical variation. To determine the incidence, clinical profile and histological pattern of IgAN in our institute, we reviewed all the patients who had native kidney biopsies with the diagnosis of primary IgAN during the period from 1998 to 2009 in the context of the clinical features. A total of 116 patients with IgAN were finally analyzed; 85 (73%) of the patients were male, the mean age of the patients was 29.2 ± 12.2 (range 10-70) years and the mean duration of disease was 10.4 ± 18.7 months (median: 2 months). Hypertension was present in 74 (63.2%) cases. Gross hematuria was rare. The most common clinical presentation was nephrotic syndrome, followed by chronic renal failure. The mean proteinuria level was 2.5 ± 2.3 g/day (median: 1.7 g/day) and the mean serum creatinine level was 3.04 ± 3.3 mg/dL (median:1.7 mg/dL). The morphological sub-classification (Haas): Class I was the most common (44.4%), followed by class V (23%). IgA co-deposition with C3 and lambda was the most common finding in the immunofluorescence study. The glomerular filtration rate decreased with advanced histological damage. The incidence of IgAN was 7.5%, which is lower as compared with studies from elsewhere. IgAN in our population had a more severe clinical presentation.
Jiang, Mengjie; Jiang, Xiaoyun; Rong, Liping; Xu, Yuanyuan; Chen, Lizhi; Qiu, Zeting; Mo, Ying
Immunoglobulin A nephropathy (IgAN) is an immunopathologic diagnosis based on a renal biopsy, it is characterized by deposits of IgA-containing immune complexes in the mesangium. Adults with IgAN have a galactose-deficient IgA1 in the circulation and glomerular deposition. There are few studies on the glycosylation of serum IgA1 in children with IgAN. To measure the serum levels of galactose-deficient IgA1 in pediatric patients with IgAN, 72 biopsy-proven IgAN children were divided into 3 groups based on the clinical features: isolated hematuria group (24 patients), hematuria and proteinuria group (22 patients), and nephritic syndrome group (26 patients). They were also divided into 3 groups according to pathologic grading: grade I + II group (25 patients), grade III group (33 patients) and grade IV + V group (14 patients). 30 healthy children were recruited as a control group. We used vicia villosa lectin binding enzyme-linked immunosorbent assay to measure the serum levels of galactose-deficient IgA1 in all groups and controls. Serum levels of galactose-deficient IgA1 in children with IgAN were higher than controls (P < 0.01). There were no significant differences in serum levels of galactose-deficient IgA1 among the different clinical and pathologic grading groups. The values of the area under the curve for galactose-deficient IgA1 levels were 0.976 (95% CI, 0.953-1.000). The cutoff point for galactose-deficient IgA1 levels was 0.125, with a sensitivity of 87.5% and a specificity of 83.3%, with a positive predictive value of 92.6% and a negative predictive value of 73.5% (P < 0.01). Children with IgAN presented serum galactose-deficient IgA1, which has shown no relationship with the clinical manifestations and pathologic grading of the disease. Detection of serum galactose-deficient IgA1 levels by vicia villosa lectin binding enzyme-linked immunosorbent assay has a certain clinical value in diagnosis of children with IgAN.
Hansen, James E.; Chan, Grace; Liu, Yanfeng; Hegan, Denise C.; Dalal, Shibani; Dray, Eloise; Kwon, Youngho; Xu, Yuanyuan; Xu, Xiaohua; Peterson-Roth, Elizabeth; Geiger, Erik; Liu, Yilun; Gera, Joseph; Sweasy, Joann B.; Sung, Patrick; Rockwell, Sara; Nishimura, Robert N.; Weisbart, Richard H.; Glazer, Peter M.
Systemic lupus erythematosus (SLE) is distinct among autoimmune diseases due to its association with circulating autoantibodies reactive against host DNA. The precise role that anti-DNA antibodies play in SLE pathophysiology remains to be elucidated, and potential applications of lupus autoantibodies in cancer therapy have not previously been explored. Here we report the unexpected finding that a cell-penetrating lupus autoantibody, 3E10, has potential as a targeted therapy for DNA-repair deficient malignancies. We find that 3E10 preferentially binds DNA single-strand tails, inhibits key steps in DNA single-strand and double-strand break repair, and sensitizes cultured tumor cells and human tumor xenografts to DNA-damaging therapy, including doxorubicin and radiation. Moreover, we demonstrate that 3E10 alone is synthetically lethal to BRCA2-deficient human cancer cells and selectively sensitizes such cells to low dose doxorubicin. Our results establish an approach to cancer therapy that we expect will be particularly applicable to BRCA2-related malignancies such as breast, ovarian, and prostate cancers. In addition, our findings raise the possibility that lupus autoantibodies may be partly responsible for the intrinsic deficiencies in DNA repair and the unexpectedly low rates of breast, ovarian, and prostate cancers observed in SLE patients. In summary, this study provides the basis for the potential use of a lupus anti-DNA antibody in cancer therapy and identifies lupus autoantibodies as a potentially rich source of therapeutic agents. PMID:23100628
Hansen, James E; Chan, Grace; Liu, Yanfeng; Hegan, Denise C; Dalal, Shibani; Dray, Eloise; Kwon, Youngho; Xu, Yuanyuan; Xu, Xiaohua; Peterson-Roth, Elizabeth; Geiger, Erik; Liu, Yilun; Gera, Joseph; Sweasy, Joann B; Sung, Patrick; Rockwell, Sara; Nishimura, Robert N; Weisbart, Richard H; Glazer, Peter M
Systemic lupus erythematosus (SLE) is distinct among autoimmune diseases because of its association with circulating autoantibodies reactive against host DNA. The precise role that anti-DNA antibodies play in SLE pathophysiology remains to be elucidated, and potential applications of lupus autoantibodies in cancer therapy have not previously been explored. We report the unexpected finding that a cell-penetrating lupus autoantibody, 3E10, has potential as a targeted therapy for DNA repair-deficient malignancies. We find that 3E10 preferentially binds DNA single-strand tails, inhibits key steps in DNA single-strand and double-strand break repair, and sensitizes cultured tumor cells and human tumor xenografts to DNA-damaging therapy, including doxorubicin and radiation. Moreover, we demonstrate that 3E10 alone is synthetically lethal to BRCA2-deficient human cancer cells and selectively sensitizes such cells to low-dose doxorubicin. Our results establish an approach to cancer therapy that we expect will be particularly applicable to BRCA2-related malignancies such as breast, ovarian, and prostate cancers. In addition, our findings raise the possibility that lupus autoantibodies may be partly responsible for the intrinsic deficiencies in DNA repair and the unexpectedly low rates of breast, ovarian, and prostate cancers observed in SLE patients. In summary, this study provides the basis for the potential use of a lupus anti-DNA antibody in cancer therapy and identifies lupus autoantibodies as a potentially rich source of therapeutic agents.
Satoh, M.; Kuroda, Y.; Yoshida, H.; Behney, K.M.; Mizutani, A.; Akaogi, J.; Nacionales, D.C.; Lorenson, T.D.; Rosenbauer, R.J.; Reeves, W.H.
Exposure to the hydrocarbon oil pristane induces lupus specific autoantibodies in non-autoimmune mice. We investigated whether the capacity to induce lupus-like autoimmunity is a unique property of pristane or is shared by other adjuvant oils. Seven groups of 3-month-old female BALB/cJ mice received a single intraperitoneal injection of pristane, squalene (used in the adjuvant MF59), incomplete Freund's adjuvant (IFA), three different medicinal mineral oils, or saline, respectively. Serum autoantibodies and peritoneal cytokine production were measured. In addition to pristane, the mineral oil Bayol F (IFA) and the endogenous hydrocarbon squalene both induced anti-nRNP/Sm and -Su autoantibodies (20% and 25% of mice, respectively). All of these hydrocarbons had prolonged effects on cytokine production by peritoneal APCs. However, high levels of IL-6, IL-12, and TNF?? production 2-3 months after intraperitoneal injection appeared to be associated with the ability to induce lupus autoantibodies. The ability to induce lupus autoantibodies is shared by several hydrocarbons and is not unique to pristane. It correlates with stimulation of the production of IL-12 and other cytokines, suggesting a relationship with a hydrocarbon's adjuvanticity. The potential to induce autoimmunity may complicate the use of oil adjuvants in human and veterinary vaccines. ?? 2003 Elsevier Ltd. All rights reserved.
This viewpoint review provides an integrative picture of seemingly contradictory work published on N-methyl-d-aspartate receptor 1 (NMDAR1) autoantibodies (AB). Based on the present state of knowledge, it gives recommendations for the clinical decision process regarding immunosuppressive treatment. Brain antigen-directed AB in general and NMDAR1-AB in particular belong to a preexisting autoimmune repertoire of mammals including humans. Specific autoimmune reactive B cells may get repeatedly (perhaps transiently) boosted by various potential stimulants (e.g., microbiome, infections, or neoplasms) plus less efficiently suppressed over lifespan (gradual loss of tolerance), likely explaining the increasing seroprevalence upon aging (>20% NMDAR1-AB in 80-year-old humans). Pathophysiological significance emerges (I) when AB-specific plasma cells settle in the brain and produce large amounts of brain antigen-directed AB intrathecally and/or (II) in conditions of compromised blood–brain barrier (BBB), for instance, upon injury, infection, inflammation, or genetic predisposition (APOE4 haplotype), which then allows substantial access of circulating AB to the brain. Regarding NMDAR1-AB, functional effects on neurons in vitro and elicitation of brain symptoms in vivo have been demonstrated for immunoglobulin (Ig) classes, IgM, IgA, and IgG. Under conditions of brain inflammation, intrathecal production and class switch to IgG may provoke high NMDAR1-AB (and other brain antigen-directed AB) levels in cerebrospinal fluid (CSF) and serum, causing the severe syndrome named “anti-NMDAR encephalitis,” which then requires immunosuppressive therapy on top of the causal encephalitis treatment (if available). However, negative CSF NMDAR1-AB results cannot exclude chronic effects of serum NMDAR1-AB on the central nervous system, since the brain acts as “immunoprecipitator,” particularly in situations of compromised BBB. In any case of suspected symptomatic consequences of
Lechner, Sebastian M; Papista, Christina; Chemouny, Jonathan M; Berthelot, Laureline; Monteiro, Renato C
Immunoglobulin A nephropathy (IgAN) or Berger's disease is the most common form of primary glomerulonephritis in the world and one of the first causes of end-stage renal failure. IgAN is characterized by the accumulation of immune complexes containing polymeric IgA1 in mesangial areas. The pathogenesis of this disease involves the deposition of polymeric and hypogalactosylated IgA1 (Gd-IgA1) in the mesangium. Quantitative and structural changes of Gd-IgA1 play a key role in the development of the disease due to functional abnormalities of two IgA receptors: the FcαRI (CD89) expressed by blood myeloid cells and the transferrin receptor (CD71) on mesangial cells. Abnormal Gd-IgA1 induces release of soluble CD89, which participates in the formation of circulating IgA1 complexes. These complexes are trapped by CD71 that is overexpressed on mesangial cells in IgAN patients together with the crosslinking enzyme transglutaminase 2 allowing pathogenic IgA complex formation in situ and mesangial cell activation. A humanized mouse model expressing IgA1 and CD89 develops IgAN in a similar manner as patients. In this model, a food antigen, the gliadin, was shown to be crucial for circulating IgA1 complex formation and deposition, which could be prevented by a gluten-free diet. Identification of these new partners opens new therapeutic prospects for IgAN treatment.
Balkenhohl, T; Lisdat, F
An immunosensor has been developed for the detection of autoantibodies directed against wheat gliadin, a protein fraction of cereal gluten which is involved in celiac disease. The immunosensor is based on the immobilization of gliadins onto gold electrodes covered with a polyelectrolyte layer of poly(4-styrenesulfonic acid sodium salt). The immobilization was monitored by quartz crystal microbalance (QCM) analysis. The antigen-antibody interaction signal was amplified by an incubation step with peroxidase-labeled immunoglobulins and subsequent peroxidase-catalyzed oxidation of 3-amino-9-ethylcarbazole (AEC). Changes in the insulating properties of the electrode layer were measured by electrochemical impedance spectroscopy (EIS) in the presence of ferri/ferro-cyanide. Impedance spectra could be fitted to a Randles equivalent circuit with high accuracy. Exposing the sensor electrodes to various antigliadin antibody concentrations resulted in proportional changes in the charge transfer resistance. A calibration graph for the detection of antigliadin antibodies was established for antibody concentrations between 10(-8) and 10(-6) M. Finally, the sensor was used for the determination of antigliadin autoantibodies of the IgG and IgA type in several human sera.
Rosales-Rivera, Luis Carlos; Dulay, Samuel; Lozano-Sánchez, Pablo; Katakis, Ioanis; Acero-Sánchez, Josep Lluís; O'Sullivan, Ciara K
A simple and rapid immunosensor for the determination of the celiac disease-related antibody, anti-tissue transglutaminase, was investigated. The antigenic protein tissue transglutaminase was chemically modified, introducing disulfide groups through different moieties of the molecule (amine, carboxylic, and hydroxyl groups), self-assembled on gold surfaces, and used for the detection of IgA and IgG autoantibodies. The modified proteins were evaluated using enzyme-linked immunosorbent assay and surface plasmon resonance, which showed that only introduction of the disulfide groups through amine moieties in the tissue transglutaminase preserved its antigenic properties. The disulfide-modified antigen was co-immobilized via chemisorption with a poly(ethylene glycol) alkanethiol on gold electrodes. The modified electrodes were then exposed to IgA anti-tissue transglutaminase antibodies and subsequently to horseradish peroxidase-labeled anti-idiotypic antibodies, achieving a detection limit of 260 ng ml(-1). Immunosensor performance in the presence of complex matrixes, including clinically relevant serum reference solutions and real patient samples, was evaluated. The introduction of disulfides in the antigenic protein enabled a simple and convenient one-step surface immobilization procedure involving only spontaneous gold-thiol covalent binding. Complete amperometric assay time was 30 min.
De Langhe, Ellen; Bossuyt, Xavier; Shen, Long; Malyavantham, Kishore; Ambrus, Julian L.; Suresh, Lakshmanan
Background: Antibodies to salivary gland protein 1 (SP1), carbonic anhydrase 6 (CA6) and parotid secretory protein (PSP) were discovered in an animal model of Sjogren’s syndrome (SS). Their expression was noted in patients with SS, especially those with lower focus scores on lip biopsies and those with early disease lacking antibodies to Ro and La. Objective: The current studies evaluated these autoantibodies in patients with long-standing SS expressing high levels of anti-Ro antibodies and in patients with Sjogren’s syndrome secondary to systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and mixed connective tissue disease (MCTD). Method: Sera were obtained from patients and evaluated by ELISA for IgG, IgA and IgM antibodies to SP1, CA6 and PSP. Results: IgA anti-CA6 antibodies were noted in 38% of these patients, but anti-SP1, CA6 and PSP IgM or IgG antibodies were identified only in a minority of patients. In patients with secondary SS, antibodies to SP1/CA6/PSP were more sensitive and specific than anti-Ro . Conclusion: While more studies are needed, antibodies to SP1, CA6 and PSP provide valuable markers for the diagnosis of primary and secondary SS, especially early in the course of the disease. PMID:28400867
Utiyama, Shirley R R; Zenatti, Katiane B; Nóbrega, Heloisa A J; Soares, Juliana Z C; Skare, Thelma L; Matsubara, Caroline; Muzzilo, Dominique A; Nisihara, Renato M
Autoimmune liver diseases (ALDs) are known to be associated with systemic autoimmune rheumatic diseases (SARDs) and their autoantibodies. We aimed to study the prevalence of SARDs and related autoantibodies, as well as their prognostic implications in a group of patients with ALDs. This was a cross-sectional study. Sixty patients with ALDs (38.3% with autoimmune hepatitis; 11.7% with primary biliary cirrhosis; 25% with primary sclerosing cholangitis and 25% with overlap syndrome) were studied for the presence of SARDs and their autoantibodies. There was autoimmune rheumatic disease in 20% of the studied sample. Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) were the commonest (11.6% and 5%, respectively). Antinuclear antibodies (ANAs) were present in 35% of the patients, followed by anti-Ro (20.0%); anti-nucleosome (18.3%); rheumatoid factor (10%) anti-CCP (8.3%); anti-RNP (8.3%); anti-ds-DNA (6.6%); anti-La (3.3%); anti-Sm (3.3%), anti-ribosomal P (3.3%). Anti-Ro (p = 0.0004), anti-La (p = 0.03), anti-RNP (p = 0.04) and anti-Sm (p = 0.03) were commonly found in patients with SARD, but not anti-DNA, anti-nucleosome and anti-ribosomal P. No differences were found in liver function tests regarding to the presence of autoantibodies. There was a high prevalence of SARD and their autoantibodies in ALD patients. Anti-Ro, anti-La, anti-RNP and anti-Sm positivity points to an association with systemic autoimmune rheumatic diseases. The presence of autoantibodies was not related to liver function tests.
Suzuki, Hitoshi; Moldoveanu, Zina; Hall, Stacy; Brown, Rhubell; Vu, Huong L.; Novak, Lea; Julian, Bruce A.; Tomana, Milan; Wyatt, Robert J.; Edberg, Jeffrey C.; Alarcón, Graciela S.; Kimberly, Robert P.; Tomino, Yasuhiko; Mestecky, Jiri; Novak, Jan
Aberrant glycosylation of IgA1 plays an essential role in the pathogenesis of IgA nephropathy. This abnormality is manifested by a deficiency of galactose in the hinge-region O-linked glycans of IgA1. Biosynthesis of these glycans occurs in a stepwise fashion beginning with the addition of N-acetylgalactosamine by the enzyme N-acetylgalactosaminyltransferase 2 and continuing with the addition of either galactose by β1,3-galactosyltransferase or a terminal sialic acid by a N-acetylgalactosamine–specific α2,6-sialyltransferase. To identify the molecular basis for the aberrant IgA glycosylation, we established EBV-immortalized IgA1-producing cells from peripheral blood cells of patients with IgA nephropathy. The secreted IgA1 was mostly polymeric and had galactose-deficient O-linked glycans, characterized by a terminal or sialylated N-acetylgalactosamine. As controls, we showed that EBV-immortalized cells from patients with lupus nephritis and healthy individuals did not produce IgA with the defective galactosylation pattern. Analysis of the biosynthetic pathways in cloned EBV-immortalized cells from patients with IgA nephropathy indicated a decrease in β1,3-galactosyltransferase activity and an increase in N-acetylgalactosamine–specific α2,6-sialyltransferase activity. Also, expression of β1,3-galactosyltransferase was significantly lower, and that of N-acetylgalactosamine–specific α2,6-sialyltransferase was significantly higher than the expression of these genes in the control cells. Thus, our data suggest that premature sialylation likely contributes to the aberrant IgA1 glycosylation in IgA nephropathy and may represent a new therapeutic target. PMID:18172551
Eijgenraam, J W; Oortwijn, B D; Kamerling, S W A; de Fijter, J W; van den Wall Bake, A W L; Daha, M R; van Kooten, C
Secretory immunoglobulin A (SIgA), although generated at mucosal surfaces, is also found in low concentrations in the circulation. Recently, SIgA was demonstrated in mesangial deposits of patients with immunoglobulin A nephropathy (IgAN), suggesting a role in the pathogenesis. This finding is in line with the belief that high molecular weight (HMW) immunoglobulin A (IgA) is deposited in the kidney. However, there is little information on the size distribution of antigen-specific IgA in circulation upon mucosal challenge. In this study we measured antigen-specific IgA, including SIgA, in serum following challenge of IgAN patients and controls via intranasal vaccination with a neoantigen, cholera toxin subunit B (CTB). We size-fractionated serum and nasal washes to study the size distribution of total IgA, SIgA and CTB-specific IgA. Finally, we compared the size distribution of antigen-specific IgA after mucosal immunization with the distribution upon systemic immunization. A significant induction of antigen-specific SIgA was detectable in serum of both patients with IgAN and controls after mucosal immunization with CTB. Independent of the route of immunization, in both groups the antigen-specific IgA response was predominantly in the polymeric IgA fractions. This is in contrast to total IgA levels in serum that are predominantly monomeric. We conclude that mucosal challenge results in antigen-specific SIgA in the circulation, and that the antigen-specific IgA response in both IgAN patients and in controls is of predominantly HMW in nature. No differences between IgAN patients and controls were detected, suggesting that the size distribution of antigen-specific IgA in the circulation is not disturbed specifically in IgAN patients.
Wang, Yang; Liu, Liping; Moore, Daniel J; Shen, Xi; Peek, Richard M.; Acra, Sari A; Li, Hui; Ren, Xiubao; Polk, D Brent; Yan, Fang
p40, a Lactobacillus rhamnosus GG (LGG)-derived protein, transactivates epidermal growth factor receptor (EGFR) in intestinal epithelial cells, leading to amelioration of intestinal injury and inflammation. To elucidate mechanisms by which p40 regulates mucosal immunity to prevent inflammation, this study aimed to determine the effects and mechanisms of p40 on regulation of a proliferation-inducing ligand (APRIL) expression in intestinal epithelial cells for promoting IgA production. p40 up-regulated April gene expression and protein production in mouse small intestine epithelial (MSIE) cells, which were inhibited by blocking EGFR expression and kinase activity. Enteroids from Egfrfl/fl , but not Egfrfl/fl-Vil-Cre mice with EGFR specifically deleted in intestinal epithelial cells, exhibited increased April gene expression by p40 treatment. p40-conditioned media from MSIE cells increased B cell class switching to IgA+ cells and IgA production, which was suppressed by APRIL receptor neutralizing antibodies. Treatment of B cells with p40 did not show any effects on IgA production. p40 treatment increased April gene expression and protein production in small intestinal epithelial cells, fecal IgA levels, IgA+B220+, IgA+CD19+, and IgA+ plasma cells in lamina propria of Egfrfl/fl, but not Egfrfl/fl-Vil-Cre mice. Thus, p40 up-regulates EGFR-dependent APRIL production in intestinal epithelial cells, which may contribute to promoting IgA production. PMID:27353252
Pascal, Virginie; Laffleur, Brice; Debin, Arnaud; Cuvillier, Armelle; van Egmond, Marjolein; Drocourt, Daniel; Imbertie, Laurent; Pangault, Céline; Tarte, Karin; Tiraby, Gérard; Cogné, Michel
Background While most antibody-based therapies use IgG because of their well-known biological properties, some functional limitations of these antibodies call for the development of derivatives with other therapeutic functions. Although less abundant than IgG in serum, IgA is the most abundantly produced Ig class in humans. Besides the specific targeting of its dimeric form to mucosal areas, IgA was shown to recruit polymorphonuclear neutrophils against certain targets more efficiently than does IgG1. Design and Methods In this study, we investigated the various pathways by which anti-tumor effects can be mediated by anti-CD20 IgA against lymphoma cells. Results We found that polymeric human IgA was significantly more effective than human IgG1 in mediating direct killing or growth inhibition of target cells in the absence of complement. We also demonstrated that this direct killing was able to indirectly induce the classical pathway of the complement cascade although to a lesser extent than direct recruitment of complement by IgG. Recruitment of the alternative complement pathway by specific IgA was also observed. In addition to activating complement for lysis of lymphoma cell lines or primary cells from patients with lymphoma, we showed that monomeric anti-CD20 IgA can effectively protect mice against tumor development in a passive immunization strategy and we demonstrated that this protective effect may be enhanced in mice expressing the human FcαRI receptor on their neutrophils. Conclusions We show that anti-CD20 IgA antibodies have original therapeutic properties against lymphoma cells, with strong direct effects, ability to recruit neutrophils for cell cytotoxicity and even recruitment of complement, although largely through an indirect way. PMID:22689689
Petitpierre, Stéphanie; Aubert, Vincent; Leimgruber, Annette; Spertini, François; Bart, Pierre-Alexandre
Autoantibodies are frequently determined in unclear clinical situations and in the context of an inflammatory syndrome. The aim of this article is not to review all autoantibodies in details, but to discuss those used in clinical practice by describing their methods of detection and interpretation. Thus we will focus on antinuclear antibodies (ANA), which are typically associated with connective tissue diseases, as well as anti-neutrophil cytoplasmic antibodies (ANCA), which are useful in the diagnosis of ANCA-associated vasculitides. Due to its high sensitivity indirect immunofluorescence is used as a screening test; when positive, ELISA is performed to search for antibodies more specifically associated with certain auto-immune diseases.
Sugahara, Hirosuke; Okai, Shinsaku; Odamaki, Toshitaka; Wong, Chyn B; Kato, Kumiko; Mitsuyama, Eri; Xiao, Jin-Zhong; Shinkura, Reiko
Gut microbiota is known to change with aging; however, the underlying mechanisms have not been well elucidated. Immunoglobulin A (IgA) is the dominant class of antibody secreted by the intestinal mucosa, and are thought to play a key role in the regulation of the gut microbiota. T cells regulate the magnitude and nature of microbiota-specific IgA responses. However, it is also known that T cells become senescent in elderly people. Therefore, we speculated that the age-related changes of IgA response against the gut microbiota might be one of the mechanisms causing the age-associated changes of gut microbiota composition. To prove our hypothesis, fecal samples from 40 healthy subjects (adult group: n = 20, an average of 35 years old; elderly group: n = 20, an average of 76 years old) were collected, and the gut microbiota composition and the response of IgA to gut microbiota were investigated. The relative abundance of Bifidobacteriaceae was significantly lower, whereas those of Clostridiaceae, Clostridiales;f__ and Enterobacteriaceae were significantly higher in the elderly group than in the adult group. There was no significant difference in the fecal IgA concentration between the adult and elderly groups. However, the taxon-specific IgA response to some bacterial taxa was different between the adult and elderly groups. To evaluate inter-group differences in the taxon-specific IgA response to each bacterial taxon, the IgA-indices were calculated, and the IgA-indices of Clostridiaceae and Enterobacteriaceae were found to be significantly lower in the elderly group than the adult group. In addition, Clostridiales;f__ and Enterobacteriaceae were significantly enriched in the IgA(+) fraction in the adult group but not in the elderly group, whereas Clostridiaceae was significantly enriched in the IgA(-) fraction in the elderly group but not in the adult group. Some species assigned to Clostridiaceae or Enterobacteriaceae are known to be pathogenic bacteria. Our results
Haddon, D James; Diep, Vivian K; Price, Jordan V; Limb, Cindy; Utz, Paul J; Balboni, Imelda
Pediatric systemic lupus erythematosus (pSLE) patients often initially present with more active and severe disease than adults, including a higher frequency of lupus nephritis. Specific autoantibodies, including anti-C1q, anti-DNA and anti-alpha-actinin, have been associated with kidney involvement in SLE, and DNA antibodies are capable of initiating early-stage lupus nephritis in severe combined immunodeficiency (SCID) mice. Over 100 different autoantibodies have been described in SLE patients, highlighting the need for comprehensive autoantibody profiling. Knowledge of the antibodies associated with pSLE and proliferative nephritis will increase the understanding of SLE pathogenesis, and may aid in monitoring patients for renal flare. We used autoantigen microarrays composed of 140 recombinant or purified antigens to compare the serum autoantibody profiles of new-onset pSLE patients (n = 45) to healthy controls (n = 17). We also compared pSLE patients with biopsy-confirmed class III or IV proliferative nephritis (n = 23) and without significant renal involvement (n = 18). We performed ELISA with selected autoantigens to validate the microarray findings. We created a multiple logistic regression model, based on the ELISA and clinical information, to predict whether a patient had proliferative nephritis, and used a validation cohort (n = 23) and longitudinal samples (88 patient visits) to test its accuracy. Fifty autoantibodies were at significantly higher levels in the sera of pSLE patients compared to healthy controls, including anti-B cell-activating factor (BAFF). High levels of anti-BAFF were associated with active disease. Thirteen serum autoantibodies were present at significantly higher levels in pSLE patients with proliferative nephritis than those without, and we confirmed five autoantigens (dsDNA, C1q, collagens IV and X and aggrecan) by ELISA. Our model, based on ELISA measurements and clinical variables, correctly identified patients with proliferative
Wang, Y; Liu, L; Moore, D J; Shen, X; Peek, R M; Acra, S A; Li, H; Ren, X; Polk, D B; Yan, F
p40, a Lactobacillus rhamnosus GG (LGG)-derived protein, transactivates epidermal growth factor receptor (EGFR) in intestinal epithelial cells, leading to amelioration of intestinal injury and inflammation. To elucidate mechanisms by which p40 regulates mucosal immunity to prevent inflammation, this study aimed to determine the effects and mechanisms of p40 on regulation of a proliferation-inducing ligand (APRIL) expression in intestinal epithelial cells for promoting immunoglobulin A (IgA) production. p40 upregulated April gene expression and protein production in mouse small intestine epithelial (MSIE) cells, which were inhibited by blocking EGFR expression and kinase activity. Enteroids from Egfr(fl/fl), but not Egfr(fl/fl)-Vil-Cre mice with EGFR specifically deleted in intestinal epithelial cells, exhibited increased April gene expression by p40 treatment. p40-conditioned media from MSIE cells increased B-cell class switching to IgA(+) cells and IgA production, which was suppressed by APRIL receptor-neutralizing antibodies. Treatment of B cells with p40 did not show any effects on IgA production. p40 treatment increased April gene expression and protein production in small intestinal epithelial cells, fecal IgA levels, IgA(+)B220(+), IgA(+)CD19(+), and IgA(+) plasma cells in lamina propria of Egfr(fl/fl), but not of Egfr(fl/fl)-Vil-Cre, mice. Thus p40 upregulates EGFR-dependent APRIL production in intestinal epithelial cells, which may contribute to promoting IgA production.
Dicker, Martina; Tschofen, Marc; Maresch, Daniel; König, Julia; Juarez, Paloma; Orzaez, Diego; Altmann, Friedrich; Steinkellner, Herta; Strasser, Richard
The production of therapeutic antibodies to combat pathogens and treat diseases, such as cancer is of great interest for the biotechnology industry. The recent development of plant-based expression systems has demonstrated that plants are well-suited for the production of recombinant monoclonal antibodies with defined glycosylation. Compared to immunoglobulin G (IgG), less effort has been undertaken to express immunoglobulin A (IgA), which is the most prevalent antibody class at mucosal sites and a promising candidate for novel recombinant biopharmaceuticals with enhanced anti-tumor activity. Here, we transiently expressed recombinant human IgA1 against the VP8* rotavirus antigen in glyco-engineered ΔXT/FT Nicotiana benthamiana plants. Mass spectrometric analysis of IgA1 glycopeptides revealed the presence of complex biantennary N-glycans with terminal N-acetylglucosamine present on the N-glycosylation site of the CH2 domain in the IgA1 alpha chain. Analysis of the peptide carrying nine potential O-glycosylation sites in the IgA1 alpha chain hinge region showed the presence of plant-specific modifications including hydroxyproline formation and the attachment of pentoses. By co-expression of enzymes required for initiation and elongation of human O-glycosylation it was possible to generate disialylated mucin-type core 1 O-glycans on plant-produced IgA1. Our data demonstrate that ΔXT/FT N. benthamiana plants can be engineered toward the production of recombinant IgA1 with defined human-type N- and O-linked glycans. PMID:26858738
Dicker, Martina; Tschofen, Marc; Maresch, Daniel; König, Julia; Juarez, Paloma; Orzaez, Diego; Altmann, Friedrich; Steinkellner, Herta; Strasser, Richard
The production of therapeutic antibodies to combat pathogens and treat diseases, such as cancer is of great interest for the biotechnology industry. The recent development of plant-based expression systems has demonstrated that plants are well-suited for the production of recombinant monoclonal antibodies with defined glycosylation. Compared to immunoglobulin G (IgG), less effort has been undertaken to express immunoglobulin A (IgA), which is the most prevalent antibody class at mucosal sites and a promising candidate for novel recombinant biopharmaceuticals with enhanced anti-tumor activity. Here, we transiently expressed recombinant human IgA1 against the VP8* rotavirus antigen in glyco-engineered ΔXT/FT Nicotiana benthamiana plants. Mass spectrometric analysis of IgA1 glycopeptides revealed the presence of complex biantennary N-glycans with terminal N-acetylglucosamine present on the N-glycosylation site of the CH2 domain in the IgA1 alpha chain. Analysis of the peptide carrying nine potential O-glycosylation sites in the IgA1 alpha chain hinge region showed the presence of plant-specific modifications including hydroxyproline formation and the attachment of pentoses. By co-expression of enzymes required for initiation and elongation of human O-glycosylation it was possible to generate disialylated mucin-type core 1 O-glycans on plant-produced IgA1. Our data demonstrate that ΔXT/FT N. benthamiana plants can be engineered toward the production of recombinant IgA1 with defined human-type N- and O-linked glycans.
Roberts, Ian S D
IgA nephropathy is defined by the presence of IgA-dominant or co-dominant immune deposits within glomeruli. Biopsy specimens meeting these diagnostic criteria have a range of histological changes that are reflected in the variable clinical course of IgA nephropathy. The impact of histology on outcomes in IgA nephropathy has been clarified in a number of large retrospective clinicopathological studies. These studies have consistently demonstrated that the stage of disease at presentation, as indicated by the extent of interstitial fibrosis and tubular atrophy in the biopsy, is the strongest histological predictor of renal survival. The effect of active proliferative lesions on the disease course is less clear cut, owing in part to considerable treatment bias in most published retrospective studies. There is evidence that endocapillary hypercellularity and cellular crescents are responsive to immunosuppressive therapy, but this observation requires confirmation in prospective randomized controlled trials. Future challenges include improving the reproducibility of histological scoring, particularly for the presence and extent of endocapillary lesions, and to improve prognostic modelling by combining histological data with clinical variables and biomarker data.
Orfila, C; Lepert, J C; Modesto, A; Pipy, B; Suc, J M
A retrospective study was done on 66 diabetic patients who had renal biopsies performed during 1979-1994. This review shows 10 patients who presented IgA nephropathy associated with diabetic nephropathy. Six patients had insulin-dependent diabetes mellitus and 4 patients non-insulin-dependent diabetes mellitus. All patients presented with proteinuria and 7 had hematuria. Four patients presented with renal impairment. Histologic evaluation disclosed the presence of thickened glomerular basement membranes and increased mesangial matrix in all cases, associated with nodular sclerosis in 8 cases. By immunofluorescence, diffuse mesangial IgA deposits were observed in all cases. The high incidence of the coexistence of IgA nephropathy and diabetes seems not merely coincidental. Structural and/or functional abnormalities of the glomerular basement membranes might facilitate the development of immune complex glomerular diseases. In patients with diabetes, the appearance of urinary abnormalities and/or deterioration in renal function altered the clinical history of diabetic nephropathy. The disorders are clinically suggestive of the presence of nondiabetic renal disease and raised the possibility of another pathogenetic mechanism.
Cervato, Sara; Morlin, Luca; Albergoni, Maria Paola; Masiero, Stefano; Greggio, Nella; Meossi, Cristiano; Chen, Shu; del Pilar Larosa, Maria; Furmaniak, Jadwiga; Rees Smith, Bernard; Alimohammadi, Mohammad; Kämpe, Olle; Valenzise, Mariella; Betterle, Corrado
To assess autoimmune regulator (AIRE) gene mutations, class II HLA haplotypes, and organ- or non-organ-specific autoantibodies in patients with chronic hypoparathyroidism (CH) without associated Addison's disease (AD) or chronic candidiasis (CC). Twenty-four patients who had CH without AD or CC were included in the study. AIRE gene mutations in all 14 exons were studied using PCR in 24 patients, 105 healthy controls and 15 first-degree relatives of CH patients with AIRE mutations. Human leucocyte antigens (HLA) were determined for all 24 patients and 105 healthy controls. Autoantibodies to a range of antigens including NACHT leucine-rich-repeat protein-5 (NALP5) and interferon omega (IFNω) were tested in all 24 patients. AIRE gene mutations were found in 6 of 24 (25%) patients, all females, and this was significantly higher (P < 0·001) compared with AIRE mutations found in healthy controls (2/105). Three patients (12·5%) had homozygous AIRE mutations characteristic of Autoimmune-Poly-Endocrinopathy-Candidiasis-Ectodermal-Dystrophy and all three were also positive for IFNω-autoantibodies. Three patients (12·5%) had heterozygous AIRE mutations; two of these were novel mutations. One of the patients with heterozygous AIRE mutations was positive for both NACHT leucine-rich-repeat protein 5 and IFNω autoantibodies. Heterozygous AIRE mutations were found in 10 of 15 first-degree relatives of CH patients with AIRE mutations, although none was affected by CH. Class II HLA haplotypes were not statistically different in patients with CH compared to healthy controls. Analysis of AIRE gene mutations together with serum autoantibody profile should be helpful in the assessment of patients with CH, in particular young women with associated autoimmune diseases. © 2010 Blackwell Publishing Ltd.
Bleeker, W K; Teeling, J L; Hack, C E
Recently, it has been postulated that the beneficial effect of intravenous immunoglobulins (IVIGs) in antibody-mediated autoimmune disorders is based on accelerated catabolism of autoantibodies. In the current study, in vivo experiments were performed with mice in which autoantibody production was mimicked by continuous infusion of monoclonal antibodies. In this model, a single dose of IVIG reduced the plasma concentrations of the infused immunoglobulin (Ig)G1 monoclonal antibody (mAb) by approximately 40% after 3 days, whereas the concentration of an IgA mAb was not affected. To extrapolate these findings to humans, a computational model for IgG clearance was established that accurately predicted the time course and magnitude of the decrease in IgG plasma levels observed in mice. Adapted for humans, this model predicted a gradually occurring decrease in autoantibody levels after IVIG administration (2 g/kg), with a maximum reduction of approximately 25% after 3 to 4 weeks and a continued decrease of several months. In conclusion, a single high dose of IVIG induces a relatively small but long-lasting reduction of autoantibody levels by accelerated IgG clearance. This mechanism has clinical relevance in the sense that it can fully explain, as the sole mechanism, the gradual decrease in autoantibody levels observed in several patient studies. However, in some clinical studies, larger or more rapid effects have been observed that cannot be explained by accelerated clearance. Hence, IVIG can also reduce autoantibody levels through mechanisms such as down-regulation of antibody production or neutralization by anti-idiotypic antibodies.
Bunker, Jeffrey J; Erickson, Steven A; Flynn, Theodore M; Henry, Carole; Koval, Jason C; Meisel, Marlies; Jabri, Bana; Antonopoulos, Dionysios A; Wilson, Patrick C; Bendelac, Albert
Large quantities of immunoglobulin A (IgA) are constitutively secreted by intestinal plasma cells to coat and contain the commensal microbiota, yet the specificity of these antibodies remains elusive. Here, we profiled the reactivities of single murine IgA plasma cells by cloning and characterizing large numbers of monoclonal antibodies. IgAs were not specific to individual bacterial taxa but rather polyreactive, with broad reactivity to a diverse but defined subset of microbiota. These antibodies arose at low frequencies among naïve B cells, and were selected into the IgA repertoire upon recirculation in Peyer's patches. This selection process occurred independent of microbiota or dietary antigens. Furthermore, while some IgAs acquired somatic mutations, these did not substantially influence their reactivity. These findings reveal an endogenous mechanism driving homeostatic production of polyreactive IgAs with innate specificity to microbiota. Copyright © 2017, American Association for the Advancement of Science.
Kaneko, Toshiyuki; Amano, Hirofumi; Kawano, Shinya; Minowa, Kentaro; Ando, Seiichiro; Watanabe, Takashi; Nakano, Soichiro; Suzuki, Jun; Morimoto, Shinji; Tokano, Yoshiaki; Takasaki, Yoshinari
B cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are known to be crucial for B cell maturation and survival, and increased expression of these factors in various autoimmune diseases has been reported. Human B cells produce two IgA subclasses: IgA1 and IgA2, the latter being abundant in the distal intestine, saliva, colostrum and bronchial fluid. We investigated these parameters in patients with mixed connective tissue disease (MCTD) complicated by interstitial lung disease (ILD+), and compared them with those in MCTD patients without ILD (ILD-). Sixty-three MCTD patients were divided into two groups: 21 ILD+ patients and 42 ILD- patients. In each patient group we analyzed soluble BAFF/APRIL using ELISA, and IgA1 and IgA2 using double immunodiffusion. Furthermore, we analyzed BAFF-APRIL receptors, BCMA, BAFF-R and TACI, using flow cytometry. The ILD+ patients had significantly higher levels of BAFF/APRIL than the ILD- patients. There were significant correlations between BAFF/APRIL, BAFF/KL-6 and APRIL/KL-6. Although there was no significant inter-group difference in the serum IgA1 level, ILD+ patients had a significantly elevated IgA2 level in comparison with ILD- patients. Moreover, although there were no significant inter-group differences in the expression of BCMA, BAFF-R and TACI on B cells, the expression of BAFF-R was significantly decreased in the ILD+ patients. In recent years, relationships between BAFF/APRIL and IgA subclass have been reported. Our results suggest that an elevated level of BAFF/APRIL drives the maturation of B cells, subsequently leading to IgA2 class switching, and possibly to the development of ILD in patients with MCTD.
Burnett, D; Chamba, A; Stockley, R A; Murphy, T F; Hill, S L
IgA is the major antibody class in mucosal secretions, yet its biological functions remain poorly understood and its role as an opsonin for neutrophils has been the subject of controversy. It has been reported that treatment of neutrophils with granulocyte-macrophage colony stimulating factor (GM-CSF) induces the cells to phagocytose particles opsonised with IgA. A study was performed to investigate the effects of GM-CSF and IgA opsonisation on the ability of human neutrophils to recognise and phagocytose latex beads coated with the P6 outer membrane protein of Haemophilus influenzae. Human neutrophils with and without preincubation with 100 pmol/l GM-CSF, were incubated with non-opsonised P6-coated latex beads or beads opsonised with IgA purified from the blood of a bronchiectatic patient with high titres of IgA anti-P6. Phagocytosis was measured by counting internalised beads during microscopic examination. The phagocytosis of IgA opsonised beads by untreated neutrophils (mean (SE) 2.1 (0.43) beads/cell) was significantly greater than that of non-opsonised beads (mean (SE) 1.3 (0.30) beads/cell). Treatment of neutrophils with GM-CSF resulted in increased phagocytosis of non-opsonised beads (mean (SE) 2.1 (0.39) beads/cell) but opsonisation with IgA increased this further (mean (SE) 3.4 (0.53) beads/cell). Human neutrophils recognise and phagocytose non-opsonised particles coated with bacterial antigen. Antibodies of the IgA isotype opsonise for neutrophil phagocytosis of particles coated with bacterial antigen but this behaviour is enhanced, in an additive fashion, by treatment of the cells with GM-CSF. The results suggest that IgA and GM-CSF are important cofactors for neutrophil recognition and elimination of bacterial pathogens.
Bogdanos, Dimitrios P; Mieli-Vergani, Giorgina; Vergani, Diego
Autoantibody detection assists in the diagnosis and allows differentiation of autoimmune hepatitis (AIH) type 1 (AIH-1), characterized by antinuclear antibody (ANA) and/or smooth muscle antibody (SMA), and type 2 (AIH-2), distinguished by the presence of antibodies to liver-kidney microsome type 1 (anti-LKM1) and/or antibodies to liver cytosol type 1 (anti-LC1). Detection of atypical perinuclear antineutrophil cytoplasmic antibodies (pANCA) and anti-soluble liver antigen (SLA) antibodies can act as an additional pointer toward the diagnosis of AIH, particularly in the absence of the conventional autoantibodies. Routine autoantibody testing by indirect immunofluorescence has been recently complemented by molecular assays based on purified or recombinant antigens. Although the AIH-1-specific ANA and SMA targets need better definition, those of anti-LKM1 and anti-LC1 in AIH-2 have been clearly identified; the fine specificity of antibody reactivity and its clinical relevance to disease pathogenesis are the focus of ongoing investigation. This article critically discusses the current knowledge of the diagnostic and clinical significance of AIH-related autoantibody reactivities, focusing on key issues that the physician needs to be aware of to be able to request the appropriate testing and to interpret correctly the laboratory results within the clinical context of the patient.
McCluskey, D R; Maxwell, A P; Watt, L
We report five cases of Wegener's granulomatosis all of whom had clinical and histological evidence of disease activity at presentation and in whom autoantibodies to neutrophil antigens were detected. This test may prove useful for the diagnosis of this serious condition and help to monitor disease activity during treatment. PMID:3068870
Tsuda, Masanobu; Torgerson, Troy R; Selmi, Carlo; Gambineri, Eleonora; Carneiro-Sampaio, Magda; Mannurita, Sara Ciullini; Leung, Patrick S C; Norman, Gary L; Gershwin, M Eric
IPEX syndrome is a congenital disorder of immune regulation caused by mutations in the FOXP3 gene, which is required for the suppressive function of naturally arising CD4 + CD25 + regulatory T cells. In this case series we evaluated serum samples from 12 patients with IPEX syndrome for the presence of common autoantibodies associated with a broad range of autoimmune disorders. We note that 75% of patients (9/12) had 1 or more autoantibodies, an incidence far above the cumulative rate observed in the general population. The range of autoantibodies differed between patients and there was no predominant autoantibody or pattern of autoantibodies present in this cohort. Surprisingly, one patient had high-titer anti-mitochondrial antibodies (AMA) typically associated with primary biliary cirrhosis (PBC) although the patient had no signs of cholestasis. PBC is a well-characterized autoimmune disease that occurs primarily in women and includes the serological hallmarks of serum AMA and elevated IgM which were both present in this patient. PBC is virtually absent in children with the exception of one reported child with interleukin 2 receptor α (CD25) deficiency which is associated with an IPEX-like regulatory T cell dysfunction. Based on the present data and the available literature we suggest a direct role for CD4 + CD25 + regulatory T cells in restraining B cell autoantibody production and that defects in regulatory T cells may be crucial to the development of PBC.
Renoult, E; Cochat, P; Jonon, B; Kessler, M
Primary IgA mesangial nephropathy was first described in adults by Berger, and has been increasingly recognized in children. IgA nephropathy is a frequent type of glomerulonephritis in 3 to 15 year-old children in France. Clinical features and outcome have been defined and the progression to renal failure is possible. The pathogeny of IgA nephropathy remains unclear and is under multifactorial control and, at present, no satisfactory specific treatment is available.
Venning, Vanessa A
Linear IgA disease is one of the rarer subepidermal blistering diseases. Linear IgA disease is a chronic, acquired, autoimmune blistering disease that is characterized by subepidermal blistering and linear deposition of IgA basement membrane antibodies. The disease affects both children and adults and, although there are some differences in their clinical presentations, there is considerable overlap with shared immunopathology and immunogenetics. Copyright © 2012 Elsevier Inc. All rights reserved.
The clearest evidence that B cells play an important role in human autoimmunity is that immunotherapies that deplete B cells are very effective treatments for many autoimmune diseases. All people, healthy or ill, have autoreactive B cells, but not at the same frequency. A number of genes influence the level of these autoreactive B cells and whether they are eliminated or not during development at a central checkpoint in the bone marrow (BM) or at a later checkpoint in peripheral lymphoid tissues. These genes include those encoding proteins that regulate signaling through the B-cell receptor complex such as Btk and PTPN22, proteins that regulate innate signaling via Toll-like receptors (TLRs) such as MyD88 and interleukin-1 receptor-associated kinase 4, as well as the gene encoding the activation-induced deaminase (AID) essential for B cells to undergo class switch recombination and somatic hypermutation. Recent studies have revealed that TLR signaling elements and AID function not only in peripheral B cells to help mediate effective antibody responses to foreign antigens, but also in the BM to help remove autoreactive B-lineage cells at a very early point in B-cell development. Newly arising B cells that leave the BM and enter the blood and splenic red pulp can express both AID and TLR signaling elements like TLR7, and thus are fully equipped to respond rapidly to antigens (including autoantigens), to isotype class switch, and to undergo somatic hypermutation. These red pulp B cells may thus be an important source of autoantibody-producing cells arising particularly in extrafollicular sites, and indeed may be as significant a source of autoantibody-producing cells as B cells arising from germinal centers. PMID:23281837
Eguia del Valle, Asier; Aguirre Urízar, José Manuel; Martínez Sahuquillo, Angel
The Linear IgA deposit related disease or Linear IgA disease (LAD) is a chronic, uncommon and autoimmunological mucocutaneous disease, characterised by linear IgA deposits along the basement membrane zone. In mainly cases, moreover cutaneous lesions, there are oral mucosal and other mucosal lesions. There are also, some cases published of Linear IgA disease limited to oral mucosa. The known of this disease is important for the establishment of a correct differential diagnosis in cases of blistering mucocutaneous diseases. In this paper, we analyze the most important features of this disease, attending specially to the oral manifestations.
Shields, D. C.; Ratanachaiyavong, S.; McGregor, A. M.; Collins, A.; Morton, N. E.
Combined segregation and linkage analysis is a powerful technique for modeling linkage to diseases whose etiology is more complex than the effect of a well-described single genetic locus and for investigating the influence of single genes on various aspects of the disease phenotype. Graves disease is familial and is associated with human leukocyte antigen (HLA) allele DR3. Probands with Graves disease, as well as close relatives, have raised levels of thyroid autoantibodies. This phenotypic information additional to affection status may be considered by the computer program COMDS for combined segregation and linkage analysis, when normals are classified into diathesis classes of increasing thyroid autoantibody titer. The ordinal model considers the cumulative odds of lying in successive classes, and a single additional parameter is introduced for each gene modeled. Distributional assumptions are avoided by providing estimates of the population frequencies of each class. Evidence for linkage was increased by considering the thyroid autoantibody diathesis and by testing two-locus models. The analysis revealed evidence for linkage to HLA-DR when the strong coupling of the linked locus to allele DR3 was considered (lod score of 6.6). Linkage analysis of the residual variation revealed no evidence of linkage to Gm, but a suggestion of linkage to Km. PMID:8079993
Shields, D.C.; Ratanachaiyavong, S.; McGregor, A.M.; Collins, A.; Morton, N.E.
Combined segregation and linkage analysis is a powerful technique for modeling linkage to diseases whose etiology is more complex than the effect of a well-described single genetic locus and for investigating the influence of single genes on various aspects of the disease phenotype. Graves disease is familial and is associated with human leukocyte antigen (HLA) allele DR3. Probands with Graves disease, as well as close relatives, have raised levels of thyroid autoantibodies. This phenotypic information additional to affection status may be considered by the computer program COMDS for combined segregation and linkage analysis, when normals are classified into diathesis classes of increasing thyroid autoantibody titer. The ordinal model considers the cumulative odds of lying in successive classes, and a single additional parameter is introduced for each gene modeled. Distributional assumptions are avoided by providing estimates of the population frequencies of each class. Evidence for linkage was increased by considering the thyroid autoantibody diathesis and by testing two-locus models. The analysis revealed evidence for linkage to HLA-DR when the strong coupling of the linked locus to allele DR3 was considered (lod score of 6.6). Linkage analysis of the residual variation revealed no evidence of linkage to Gm, but a suggestion of linkage to Km. 32 refs., 10 tabs.
Khanna, Divya; Rana, Prashant Singh
Identification of antigen for inducing specific class of antibody is prime objective in peptide based vaccine designs, immunodiagnosis, and antibody productions. It's urge to introduce a reliable system with high accuracy and efficiency for prediction. In the present study, a novel multilevel ensemble model is developed for prediction of antibodies IgG and IgA. Epitope length is important in training the model and it is efficient to use variable length of epitopes. In this ensemble approach, seven different machine learning models are combined to predict variable length of epitopes (4 to 50). The proposed model of IgG specific epitopes achieves 94.43% of accuracy and IgA specific epitopes achieves 97.56% of accuracy with repeated 10-fold cross validation. The proposed model is compared with the existing system i.e. IgPred model and outcome of proposed model is improved.
Kraehenbuhl, J P; Neutra, M R
In this second article on mucosal defence and transepithelial transport, Jean-Pierre Kraehenbuhl and Marian Neutra discuss the part played by a special class of antibody, polymeric IgA, in the protection of mucosal surfaces lining the digestive, respiratory and genital tracts, and the implications for mucosal vaccines. Polymeric IgA crosslinks luminal antigens or pathogens, thus preventing their interaction with epithelial cells. Following stimulation by antigen in the organized mucosal lymphoid tissue, effector B lymphocytes enter the circulation and migrate to distant mucosal or glandular sites, where they differentiate into polymeric-IgA-producing plasma cells. These antibodies reach the environment by transport across the epithelial cells of mucosal and glandular tissues.
Sibilia, Jean; Chatelus, Emmanuel; Meyer, Alain; Gottenberg, Jacques-Eric; Sordet, Christelle; Goetz, Joëlle
The inflammatory myopathies are a group of quite proteiform, systemic auto-immune diseases which include polymyositis, dermatomyositis and inclusion body myopathies. To facilitate the diagnosis, classification criteria (Bohan and Peter, 1975) have been proposed, based essentially on clinical criteria. In addition, over the past fifteen years, auto-antibodies characterizing certain forms of inflammatory myopathy have been identified. One distinguishes schematically: auto-antibodies specific for myositis and auto-antibodies sometimes associated with myositis. Concerning the myositis specific auto-antibodies (MSA), schematically there are a dozen specificities which are classed according to the cellular distribution of the auto-antigen. The most characteristic are certainly the auto-antibodies directed against cytoplasmic antigens: the anti-tRNA synthetases (anti-Jo-1 (PL-1), anti-PL-7, PL-12, EJ, OJ, JS, KS, ZO, YRS), anti-SRP (signal recognition particle), anti-Mas and anti-KJ, anti-Fer (eEF1), anti-Wa and anti-CADM p140. Other auto-antibodies are directed against nuclear auto-antigens: the anti-Mi-2, anti-PMS (PMS1, PMS2) and related antibodies (MLH1, DNA PKcs…), anti-56 kDa, anti-MJ (NXP-2), anti-SAE and anti-p155/p140 (TIF-1γ). Concerning the auto-antibodies sometimes associated with myositis (myositis associated auto-antibodies or MAA), they can also be observed in other auto-immune diseases. These auto-antibodies are directed against nuclear or nucleolar auto-antigens: the anti-PM-Scl, anti-Ku, anti-RNP (U1 RNP and U2 RNP, U4/U6 RNP and U5 RNP), anti-Ro 52 kDa and more rarely, anti-Ro 60 kDa and anti-La. The auto-antibodies related to myositis are biological tools which are of interest in two main ways. They have allowed us to sort out the nosology of these inflammatory myopathies, in particular by defining anti-tRNA synthetase syndrome. It now remains to determine how they might be employed to complement the classical clinico-biological diagnostic criteria
Yamaji, Kenji; Suzuki, Yusuke; Suzuki, Hitoshi; Satake, Kenji; Horikoshi, Satoshi; Novak, Jan; Tomino, Yasuhiko
Whether IgA nephropathy is attributable to mesangial IgA is unclear as there is no correlation between intensity of deposits and extent of glomerular injury and no clear mechanism explaining how these mesangial deposits induce hematuria and subsequent proteinuria. This hinders the development of a specific therapy. Thus, precise events during deposition still remain clinical challenge to clarify. Since no study assessed induction of IgA nephropathy by nephritogenic IgA, we analyzed sequential events involving nephritogenic IgA from IgA nephropathy-prone mice by real-time imaging systems. Immunofluorescence and electron microscopy showed that serum IgA from susceptible mice had strong affinity to mesangial, subepithelial, and subendothelial lesions, with effacement/actin aggregation in podocytes and arcade formation in endothelial cells. The deposits disappeared 24-h after single IgA injection. The data were supported by a fluorescence molecular tomography system and real-time and 3D in vivo imaging. In vivo imaging showed that IgA from the susceptible mice began depositing along the glomerular capillary from 1 min and accumulated until 2-h on the first stick in a focal and segmental manner. The findings indicate that glomerular IgA depositions in IgAN may be expressed under the balance between deposition and clearance. Since nephritogenic IgA showed mesangial as well as focal and segmental deposition along the capillary with acute cellular activation, all glomerular cellular elements are a plausible target for injury such as hematuria. PMID:25409466
Sun, Qiang; Zhang, Zhenhai; Liu, Xiaorong
Objective Galactose-deficient IgA1 was evaluated in patients with IgA nephropathy(IgAN) and controls in order to determine the predictive value of galactose-deficient IgA1 in cases of IgA nephropathy. Methods PubMed, EMBASE, Cochrane central register of controlled trials, CNKI, CBM disc, and VIP database were searched to identify eligible studies that evaluated a difference in aberrant IgA1 glycosylation in IgAN patients compared with controls. A meta-analysis was conducted to evaluate the impact of galactose-deficient IgA1(Gd-IgA1) levels in different groups. Results A total of 22 studies (n = 1657) met inclusion criteria. The mean Newcastle-Ottawa Scale (NOS) score was 7.2 and ranged from 6 to 8. The standard mean difference(SMD) in the meta-analysis of 20 studies of the level of Gd-IgA1 in the serum and/or supernatant of cultured cells was higher in the IgAN group compared with healthy controls as well as in those with other renal diseases (SMD = 1.76, 95% CI = 1.18–2.34, P<0.00001; SMD = 1.05, 95% CI = 0.05–2.04, P = 0.04). The data synthesis suggested that IgAN patients had similar levels of serum Gd-IgA1, with no significant differences, compared with first-degree relatives and Henoch-Schonlein purpura nephritis (HSPN) patients (MD = 0.04, 95% CI = 0.00–0.08, P = 0.05; MD = -46.03, 95% CI = -217.70–125.64, P = 0.60). In addition, the combined MD of 5 studies indicated that there were no significant differences in Gd-IgA1 levels among patients with varying severities of IgAN (MD = 0.02, 95% CI = -0.02–0.05, P = 0.28). Conclusions The pooled evidence suggests that the level of Gd-IgA1 in the serum or supernatant of cultured cells from peripheral blood or tonsils may be a useful biomarker for predicting IgA nephropathy, though the level of Gd-IgA1 was not significantly associated with disease severity. PMID:27870872
Xia, Yang; Kellems, Rodney E
Hypertensive disorders are life-threatening diseases with high morbidity and mortality, affecting billions of individuals worldwide. A multitude of underlying conditions may contribute to hypertension, thus the need for a plethora of treatment options to identify the approach that best meets the needs of individual patients. A growing body of evidence indicates that (1) autoantibodies that bind to and activate the major angiotensin II type I (AT₁) receptor exist in the circulation of patients with hypertensive disorders, (2) these autoantibodies contribute to disease pathophysiology, (3) antibody titers correlate to the severity of the disease, and (4) efforts to block or remove these pathogenic autoantibodies have therapeutic potential. These autoantibodies, termed AT₁ agonistic autoantibodies have been extensively characterized in preeclampsia, a life-threatening hypertensive condition of pregnancy. As reviewed here, these autoantibodies cause symptoms of preeclampsia when injected into pregnant mice. Somewhat surprisingly, these auto antibodies also appear in 3 animal models of preeclampsia. However, the occurrence of AT₁ agonistic autoantibodies is not restricted to pregnancy. These autoantibodies are prevalent among kidney transplant recipients who develop severe transplant rejection and malignant hypertension during the first week after transplantation. AT₁ agonistic autoantibodies are also highly abundant among a group of patients with essential hypertension that are refractory to standard therapy. More recently these autoantibodies have been seen in patients with the autoimmune disease, systemic sclerosis. These 3 examples extend the clinical impact of AT₁ agonistic autoantibodies beyond pregnancy. Research reviewed here raises the intriguing possibility that preeclampsia and other hypertensive conditions are autoimmune diseases characterized by the presence of pathogenic autoantibodies that activate the major angiotensin receptor, AT₁. These
Porter, D D; Porter, H G; Suffin, S C; Larsen, A E
Aleutian disease virus (ADV) persistently infects mink and causes marked hypergammaglobulinemia. Immunoglobulin class-specific antisera were used to define the total immunoglobulin of each class by radial immunodiffusion and the immunoglobulin class of ADV-specific antibody by immunofluorescence in experimentally and naturally infected mink. Electrophoretic gamma globulin closely reflects the immunoglobulin G (IgG) level in mink, and the majority of the increased immunoglobulin and ADV antibody in infected mink is IgG. IgM becomes elevated within 6 days after infection, reaches peak levels by 15 to 18 days, and returns to normal by 60 days after infection. The first ADV antibody demonstrable is IgM, and most mink have virus-specific IgM antibody for at least 85 days postinfection. Serum IgA levels in normal mink are not normally distributed, and ADV infection causes a marked elevation of IgA. Low levels of ADV-specific IgA antibody can be shown throughout the course of infection. Failure of large amounts of virus-specific IgG antibody to inhibit the reaction of virus-specific IgM and IgA antibodies suggests that the various classes of antibodies are directed against spatially different antigenic determinants. The IgM and IgA were shown not to be rheumatoid factors. PMID:6319283
Wynne, James W; Di Rubbo, Antonio; Shiell, Brian J; Beddome, Gary; Cowled, Christopher; Peck, Grantley R; Huang, Jing; Grimley, Samantha L; Baker, Michelle L; Michalski, Wojtek P
There is now an overwhelming body of evidence that implicates bats in the dissemination of a long list of emerging and re-emerging viral agents, often causing illnesses or death in both animals and humans. Despite this, there is a paucity of information regarding the immunological mechanisms by which bats coexist with highly pathogenic viruses. Immunoglobulins are major components of the adaptive immune system. Early studies found bats may have quantitatively lower antibody responses to model antigens compared to conventional laboratory animals. To further understand the antibody response of bats, the present study purified and characterised the major immunoglobulin classes from healthy black flying foxes, Pteropus alecto. We employed a novel strategy, where IgG was initially purified and used to generate anti-Fab specific antibodies. Immobilised anti-Fab specific antibodies were then used to capture other immunoglobulins from IgG depleted serum. While high quantities of IgM were successfully isolated from serum, IgA was not. Only trace quantities of IgA were detected in the serum by mass spectrometry. Immobilised ligands specific to IgA (Jacalin, Peptide M and staphylococcal superantigen-like protein) also failed to capture P. alecto IgA from serum. IgM was the second most abundant serum antibody after IgG. A survey of mucosal secretions found IgG was the dominant antibody class rather than IgA. Our study demonstrates healthy P. alecto bats have markedly less serum IgA than expected. Higher quantities of IgG in mucosal secretions may be compensation for this low abundance or lack of IgA. Knowledge and reagents developed within this study can be used in the future to examine class-specific antibody response within this important viral host.
Shiell, Brian J.; Beddome, Gary; Cowled, Christopher; Peck, Grantley R.; Huang, Jing; Grimley, Samantha L.; Baker, Michelle L.; Michalski, Wojtek P.
There is now an overwhelming body of evidence that implicates bats in the dissemination of a long list of emerging and re-emerging viral agents, often causing illnesses or death in both animals and humans. Despite this, there is a paucity of information regarding the immunological mechanisms by which bats coexist with highly pathogenic viruses. Immunoglobulins are major components of the adaptive immune system. Early studies found bats may have quantitatively lower antibody responses to model antigens compared to conventional laboratory animals. To further understand the antibody response of bats, the present study purified and characterised the major immunoglobulin classes from healthy black flying foxes, Pteropus alecto. We employed a novel strategy, where IgG was initially purified and used to generate anti-Fab specific antibodies. Immobilised anti-Fab specific antibodies were then used to capture other immunoglobulins from IgG depleted serum. While high quantities of IgM were successfully isolated from serum, IgA was not. Only trace quantities of IgA were detected in the serum by mass spectrometry. Immobilised ligands specific to IgA (Jacalin, Peptide M and staphylococcal superantigen-like protein) also failed to capture P. alecto IgA from serum. IgM was the second most abundant serum antibody after IgG. A survey of mucosal secretions found IgG was the dominant antibody class rather than IgA. Our study demonstrates healthy P. alecto bats have markedly less serum IgA than expected. Higher quantities of IgG in mucosal secretions may be compensation for this low abundance or lack of IgA. Knowledge and reagents developed within this study can be used in the future to examine class-specific antibody response within this important viral host. PMID:23308125
IgA nephropathy (nephropathy with mesangial IgA and IgG deposits, so-called Berger's disease) is the most common primary chronic glomerulonephritis worldwide, and was first described in 1968. Histopathologically, IgA nephropathy is characterized by expansion of the glomerular mesangial matrix with mesangial cell proliferation and/or mononuclear cell infiltration. Glomeruli typically contain generalized-diffuse granular mesangial deposits of IgA (mainly IgA1), IgG and C3. This disease, therefore, is considered to be an immune-complex-mediated glomerulonephritis although the antigenic agents are still obscure. Clinically, patients with IgA nephropathy show microscopic and macroscopic hematuria and/or proteinuria. Although the clinical course is generally gradual in patients with IgA nephropathy, progression to renal hypertension, renal anemia, and end-stage kidney disease is not as rare as originally thought. Since pathogenesis and radical treatment for IgA nephropathy are still not established, it is necessary to study them using various clinical findings.
Alberta-Wszolek, Lauren; Mousette, Alyse M; Mahalingam, Meera; Levin, Nikki A
Linear IgA Bullous Dermatosis (LABD) is an immune-mediated subepidermal vesiculobullous eruption characterized by linear deposits of IgA at the basement membrane zone. Most cases are idiopathic but medications, infections, and malignancies have also been reported to induce LABD. We report the case of a 54-year-old woman who developed LABD shortly after receiving an influenza vaccination.
Sheldon, Joanna; Dellavance, Alessandra
Producing robust, certified, traceable reference material for autoantibody testing is a vital element in maintaining the validity of results that are generated in the daily clinical laboratory routine. This is a huge challenge because of the high number of variables involved in the detection and measurement of the autoantibodies. The production of such materials is time consuming and needs rigorous attention to detail; this is best achieved by an overarching independent body who will oversee the process in a "not for profit" manner. Much effort has been made to build international standards for quantitative and qualitative assays based on monoclonal antibodies, obtained from affinity purification and plasmapheresis. The big challenge is to respect individual differences in immune response to the same antigen. A promising ongoing initiative is the construction of pools with monospecific samples from different individuals.
Vernino, Steven; Lindstrom, Jon; Hopkins, Steve; Wang, Zhengbei; Low, Phillip A.
In myasthenia gravis (MG), autoantibodies bind to the α1 subunit and other subunits of the muscle nicotinic acetylcholine receptor (AChR). Autoimmune autonomic ganglionopathy (AAG) is an antibody-mediated neurological disorder caused by antibodies against neuronal AChRs in autonomic ganglia. Subunits of muscle and neuronal AChR are homologous. We examined the specificity of AChR antibodies in patients with MG and AAG. Ganglionic AChR autoantibodies found in AAG patients are specific for AChRs containing the α3 subunit. Muscle and ganglionic AChR antibody specificities are distinct. Antibody crossreactivity between AChRs with different α subunits is uncommon but can occur. PMID:18485491
Meriggioli, Matthew N; Sanders, Donald B
Myasthenia gravis is an autoimmune disorder of the neuromuscular junction. A number of molecules, including ion channels and other proteins at the neuromuscular junction, may be targeted by autoantibodies leading to abnormal neuromuscular transmission. In approximately 85% of patients, autoantibodies, directed against the postsynaptic nicotinic acetylcholine receptor can be detected in the serum and confirm the diagnosis, but in general, do not precisely predict the degree of weakness or response to therapy. Antibodies to the muscle-specific tyrosine kinase are detected in approximately 50% of generalized myasthenia gravis patients who are seronegative for anti-acetylcholine receptor antibodies, and levels of anti-muscle-specific tyrosine kinase antibodies do appear to correlate with disease severity and treatment response. Antibodies to other muscle antigens may be found in the subsets of myasthenia gravis patients, potentially providing clinically useful diagnostic information, but their utility as relevant biomarkers (measures of disease state or response to treatment) is currently unclear. PMID:22882218
Zeman, Marilyn V; Hirschfield, Gideon M
Confirming whether a patient has autoimmune liver disease is challenging, given its varied presentation and complex definitions. In the continued absence of pathognomonic serum markers, diagnosis requires evaluation of laboratory investigations and, frequently, a liver biopsy - all of which need to be interpreted in the correct clinical context, with an emphasis on exclusion of viral infections, drug toxicity and metabolic disease. However, clear diagnosis is important for appropriate and timely therapy. Autoantibodies remain important tools for clinicians, and were the first proposed serological markers to aid in differentiating viral from chronic autoimmune hepatitis. Their presence is occasionally considered to be synonymous with autoimmune liver disease - a misinterpretation of their clinical significance. The present article summarizes the serum autoantibodies currently investigated in clinical and research practice, along with a description of their value in adult chronic liver diseases, with an emphasis on their appropriate use in the diagnosis and management of patients with autoimmune liver disease.
Sheldon, Joanna; Dellavance, Alessandra
Producing robust, certified, traceable reference material for autoantibody testing is a vital element in maintaining the validity of results that are generated in the daily clinical laboratory routine. This is a huge challenge because of the high number of variables involved in the detection and measurement of the autoantibodies. The production of such materials is time consuming and needs rigorous attention to detail; this is best achieved by an overarching independent body who will oversee the process in a “not for profit” manner. Much effort has been made to build international standards for quantitative and qualitative assays based on monoclonal antibodies, obtained from affinity purification and plasmapheresis. The big challenge is to respect individual differences in immune response to the same antigen. A promising ongoing initiative is the construction of pools with monospecific samples from different individuals. PMID:25972866
Pillebout, Evangéline; Nochy, Dominique
IgA nephropathy is the primitive glomerulonephritis the most frequently encountered worldwide. In about one case out of three, it is responsible for the progression from progressive renal failure to end-stage renal failure. The pathophysiological mechanisms of this disease which is mediated by immune complexes remain unclear. The presentation, clinical progression and optical microscope aspect of the renal biopsy may widely vary, making any histological classification very difficult. Most therapeutic studies include the patients only on clinical criteria of severity. The only consensual management is that of patients with a nephropathy and mild glomerular lesions and a nephritic syndrome, or with an extracapillar glomerulonephritis and a rapidly progressive renal failure; corticoids are indicated in former cases while corticoids must be combined with immunosuppressive agents in the latter ones. Corticotherapy may be considered in patients with a proteinuria higher than 1g/day without renal failure. In any patient with primitive IgA nephropathy, the overall management used for chronic glomerulopathy must be initiated, including, in case of arterial hypertension or proteinuria, the renin-angiotensin system blockade.
Daha, Mohamed R; van Kooten, Cees
Immunoglobulin A nephropathy (IgAN) is characterized by the deposition of IgA in the mesangium of glomeruli. This mesangial IgA has been found to consist mainly of polymeric IgA1 which drives the activation of the mesangial cells and results in excessive production of several inflammatory mediators. The activation of mesangial cells is amplified by the ability of IgA to activate the complement system, originally thought to occur mainly via the alternative pathway of complement. However more recent studies indicate that lectin pathway involvement has a strong association with progression of renal disease. In this review we summarize the contribution of complement to the IgA- mediated inflammatory process.
O'Shea-Alvarez, M S; Arguello-López, C; González-Robles, A; Treviño-García Manzo, N
The presence of IgA anti-Entamoeba histolytica antibodies has been demonstrates in intestinal secretions and serum of human amebiasis. We investigated which are the cellular components of trophozoites that react with IgA anti-ameba antibodies from immune serum, colostrum and human milk. The cellular localization of such antigens was accomplished by an indirect immunoperoxidase technique using anti-human IgA (alpha chain specific) labeled with peroxidase, both for light and transmission electron microscopy. Intracellular antigens were localized after permeating the parasites with cold acetone (-10 degrees C) for 3 min. and cryosections of 1 micron thick. The antigens that react with IgA antibodies from immune serum, colostrum and human milk were located in the plasma membrane and the internal portion of some cytoplasmic vesicles. So far, it is unknown what is the biological function of IgA in human amebiasis but in other systems it protects against certain parasites.
Courvalin, J C; Worman, H J
A subset of patients with primary biliary cirrhosis (PBC) have autoantibodies directed against nuclear envelope proteins. The major autoantigen is gp210, a 210 kilodalton (kD) transmembrane protein of the nuclear pore complex, that is recognized by antibodies in approximately 25% of patients. The predominant epitope in gp210 that is recognized by most of the autoantibodies is a 15 amino acid stretch in the cytoplasmic, carboxyl-terminal domain of the protein. Gp210 autoantibodies are specific for PBC, as are the less frequent autoantibodies directed against LBR, a transmembrane protein of the inner nuclear membrane. Although autoantibodies against nuclear lamins, abundant intermediate filament proteins associated with the inner nuclear membrane, may be found in PBC, they are not specific for this disease. Nuclear envelope protein autoantibodies are also present in some patients without detectable antimitochondrial antibodies and may be of particular utility in diagnosing individuals with atypical presentations of PBC.
Tomioka, Ryo; Tanaka, Keiko
Central nervous system hyperexcitability disorders, known as stiff-man/person syndrome (SPS), are thought to be related to the regulatory disturbance of inhibitory synaptic transmission of motor neurons in the brainstem and spinal cord. SPS is characterized by stiffness and spasms of the axis and limbs and is divided into two clinical subgroups: classic SPS, which affects the lumbar, trunk, and proximal limb muscles, and SPS-plus syndrome. The latter comprises (1) the stiff-limb subtype, in which symptom is limited to the lower limbs; (2) jerking stiff-man syndrome, characterized by chronically progressive stiffness and myoclonus; and (3) acute-onset and progressive encephalomyelitis with rigidity and myoclonus. Almost 80% of patients with classic SPS harbor autoantibodies against glutamic acid decarboxylase 65 (GAD65). In approximately 30-40% of patients, SPS accompanies type I diabetes, and anti-GAD65 antibodies are detected frequently in type I diabetes. However, the antibody-recognizing epitopes might be different between SPS and diabetes. Other autoantibodies against glycine receptor α1 (12% of patients with SPS) and GABA(A)-receptor associated protein (70% of patients with SPS) have been reported. In paraneoplastic SPS, anti-amphiphysin antibodies have been shown in patients with breast cancer or small cell lung cancer. One case of mediastinal tumor with anti-gephyrin antibodies has also been reported. However, the roles of these autoantibodies in the pathomechanisms of SPS have not yet been elucidated.
Real, Ana; Gilbert, Nick; Hauser, Barbara; Kennedy, Nick; Shand, Alan; Gillett, Helen; Gillett, Peter; Goddard, Clive; Cebolla, Ángel; Sousa, Carolina; Fraser, William D; Satsangi, Jack; Ralston, Stuart H; Riches, Philip L
Autoantibodies neutralising the effect of the bone regulatory cytokine osteoprotegerin (OPG) have been described in a patient with severe osteoporosis and coeliac disease. This study aimed to determine the prevalence and epitope specificity of autoantibodies to OPG in patients with coeliac disease, and correlate their presence with bone mineral density. A direct enzyme-linked immunosorbent assay was developed and used to screen patients with coeliac disease for autoantibodies to OPG. Recombinant fragments of OPG were made to evaluate the epitope specificity and affinity of these antibodies. Phenotype information of the patients was obtained by case note review. Raised titres of antibodies to OPG were found in 7/71 (9.8 %) patients with coeliac disease, compared with 1/72 (1.4 %) non-coeliac osteoporosis clinic control patients (p < 0.05). Our results suggest that a polyclonal antibody response to OPG is raised in these patients capable of recognising different epitopes of OPG with varying affinity. The titre of OPG antibodies was associated with lower bone mineral density Z-score of the hip in coeliac patients on univariate (p < 0.05) and multivariate analysis including age, sex height and weight as covariates (p < 0.01). Polyclonal antibodies to OPG are more common in patients with coeliac disease and are independently associated with lower bone mineral density Z-scores of the hip. Further work is required to establish the clinical utility of testing for OPG antibodies.
Wheeler, Christine A; Calhoun, Loni; Blackall, Douglas P
Warm reactive autoantibodies are encountered relatively frequently in tertiary care hospitals. We studied 100 consecutive patients with warm autoantibodies to correlate their clinical and serologic features. Study patients (56 male, 44 female) had various diagnoses and a mean age of 53.5 years (range, 3-90 years). Autoimmune hemolysis was documented in 29 patients; 20 patients (69%) in this subset had diseases classically associated with warm autoimmune hemolytic anemia (hematologic and autoimmune disorders). All study patients demonstrated IgG on their RBCs (direct antiglobulin test [DAT] reactivity range, microscopic to 4+); 49 also demonstrated C3 (reactivity range, microscopic to 3+). The DAT for IgG was 2+ or more in 25 (86%) of 29 patients with hemolysis; the DAT for IgG was 1+ or less in 45 (63%) of 71 patients without hemolysis. In patients with hemolysis, 21 (72%) of 29 had a DAT reactive for C3. These findings may be useful in determining the clinical significance of warm autoantibodies and the extent to which patients should be followed up for hemolysis.
Munblit, D; Sheth, S; Abrol, P; Treneva, M; Peroni, D G; Chow, L-Y; Boner, A L; Pampura, A; Warner, J O; Boyle, R J
Immunoglobulin A (IgA) is a predominant immunoglobulin present in human breast milk and is known to play an important role in infant gut immunity maturation. Breast milk composition varies between populations, but the environmental and maternal factors responsible for these variations are still unclear. We examined the relationship between different exposures and levels of IgA in colostrum. The objective of this study was to examine whether exposures analysed influence levels of IgA in colostrum. The present study used 294 colostrum samples from the MecMilk International cohort, collected from women residing in London, Moscow and Verona. Samples were analysed in automated Abbott Architect Analyser. We found an inverse correlation between time postpartum and colostrum total IgA level (r=-0.49, P<0.001). Adjusting for maternal parity, smoking, fresh fruit and fish consumption and allergen sensitization, multiple regression model showed that IgA levels were influenced by colostrum collection time (P<0.0001) and country of collection (P<0.01). Mode of delivery influence did not appear to be significant in univariate comparisons, once adjusted for the above maternal characteristics it showed a significant influence on total IgA (P=0.01). We conclude that the concentration of IgA in colostrum drops rapidly after birth and future studies should always consider this factor in analysis. IgA concentration varied significantly between countries, with the highest level detected in Moscow and lowest in Verona. Mode of delivery effect should be confirmed on larger cohorts. Further work is needed to determine ways to correct for IgA decline over time in colostrum, and to find the cause of variations in IgA levels between the countries.
Lemaitre-Coelho, I.; Yamakido, M.; Montgomery, P.C.; Langendries, A.E.; Vaerman, J.P.
Concentrated rat bronchial washings (BW) were analyzed by gel-filtration and immunochemical methods. BW contained mainly albumin, transferrin and IgG. Free secretory component and secretory IgA were identified in BW; the BW-IgA had the same three sedimentation coefficients, i.e. +/- 11 S, 13 S, 15 S by sucrose density gradient ultracentrifugation, as rat milk and rat bile IgA; the three peaks were secretory IgA. Compared to serum, and relatively to albumin, BW were significantly enriched in IgA, although much less than rat bile. Purified polyclonal rat polymeric /sup 125/I-IgA was injected intravenously into normal rats, and into rats with bile duct ligation or partial hepatectomy, which decrease the liver plasma-to-bile transfer of IgA. BW were then collected, one or four hours later, to assess the recovery of the /sup 125/I-IgA in BW and to estimate the contribution of serum IgA to BW-IgA. Very little /sup 125/I-IgA (less than 0.2%) was recovered in all BW. The specific activity, measured only in the rat with the highest recovery in BW, was 20 times lower in BW than in serum. The data demonstrate that rat serum IgA does not contribute significantly to IgA in BW.
Akasaka, Eijiro; Kayo, Sato-Jin; Nakano, Hajime; Ishii, Norito; Hashimoto, Takashi; Sawamura, Daisuke
Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is an autoimmune mucocutaneous disease characterized by subepidermal blistering induced by IgA autoantibodies against several autoantigens in the basal membranous zone of the skin and mucosal tissue. Although diaminodiphenyl sulfone (DDS), also known as dapsone, is generally recognized as the first-line therapy for LABD, DDS can induce several severe side effects. We present a Japanese case of LABD with DDS-induced hemolytic anemia and alopecia. In the present case, the DDS-induced hemolytic anemia and hair loss made the DDS monotherapy difficult. When DDS is used in LABD patients with iron deficiency anemia (IDA), hemolytic anemia is concealed by IDA. It is thus necessary to carefully and frequently examine the laboratory data to find the signs of DDS-induced hemolytic anemia. Even though there is no literature on DDS-induced alopecia, alopecia was reported as one of the side effects of DDS in an FDA report, and, in our case, hair loss was improved after reducing its dosage. We have to recognize that alopecia is one of the side effects of DDS and that careful management is needed in order not to overlook the adverse side effects of DDS when treating LABD patients.
Burnett, D; Chamba, A; Stockley, R A; Murphy, T F; Hill, S L
BACKGROUND--IgA is the major antibody class in mucosal secretions, yet its biological functions remain poorly understood and its role as an opsonin for neutrophils has been the subject of controversy. It has been reported that treatment of neutrophils with granulocyte-macrophage colony stimulating factor (GM-CSF) induces the cells to phagocytose particles opsonised with IgA. A study was performed to investigate the effects of GM-CSF and IgA opsonisation on the ability of human neutrophils to recognise and phagocytose latex beads coated with the P6 outer membrane protein of Haemophilus influenzae. METHODS--Human neutrophils with and without preincubation with 100 pmol/l GM-CSF, were incubated with non-opsonised P6-coated latex beads or beads opsonised with IgA purified from the blood of a bronchiectatic patient with high titres of IgA anti-P6. Phagocytosis was measured by counting internalised beads during microscopic examination. RESULTS--The phagocytosis of IgA opsonised beads by untreated neutrophils (mean (SE) 2.1 (0.43) beads/cell) was significantly greater than that of non-opsonised beads (mean (SE) 1.3 (0.30) beads/cell). Treatment of neutrophils with GM-CSF resulted in increased phagocytosis of non-opsonised beads (mean (SE) 2.1 (0.39) beads/cell) but opsonisation with IgA increased this further (mean (SE) 3.4 (0.53) beads/cell). CONCLUSIONS--Human neutrophils recognise and phagocytose non-opsonised particles coated with bacterial antigen. Antibodies of the IgA isotype opsonise for neutrophil phagocytosis of particles coated with bacterial antigen but this behaviour is enhanced, in an additive fashion, by treatment of the cells with GM-CSF. The results suggest that IgA and GM-CSF are important cofactors for neutrophil recognition and elimination of bacterial pathogens. Images PMID:8346495
Autoantibodies against glutamate receptors, first reported in Rasmussen encephalitis, have been observed in other focal epilepsies, central nervous system ischemic infarcts, transient ischemic attacks, sporadic olivopontocerebellar atrophy, systemic lupus erythematosus, and paraneoplastic encephalopathies. The detection of glutamate receptor autoantibodies is not useful in the evaluation of Rasmussen encephalitis but may be a biomarker for brain ischemia, and it is helpful in diagnosing certain paraneoplastic encephalopathies. Passive transfer of glutamate receptor autoantibodies from patients with systemic lupus erythematosus or paraneoplastic encephalopathy suggests that glutamate receptor autoantibodies can actively contribute to neurologic dysfunction.
Wang, Yanni; Thomson, Christy A.; Allan, Lenka L.; Jackson, Linda M.; Olson, Melanie; Hercus, Timothy R.; Nero, Tracy L.; Turner, Amanda; Parker, Michael W.; Lopez, Angel L.; Waddell, Thomas K.; Anderson, Gary P.; Hamilton, John A.; Schrader, John W.
The origin of pathogenic autoantibodies remains unknown. Idiopathic pulmonary alveolar proteinosis is caused by autoantibodies against granulocyte–macrophage colony-stimulating factor (GM-CSF). We generated 19 monoclonal autoantibodies against GM-CSF from six patients with idiopathic pulmonary alveolar proteinosis. The autoantibodies used multiple V genes, excluding preferred V-gene use as an etiology, and targeted at least four nonoverlapping epitopes on GM-CSF, suggesting that GM-CSF is driving the autoantibodies and not a B-cell epitope on a pathogen cross-reacting with GM-CSF. The number of somatic mutations in the autoantibodies suggests that the memory B cells have been helped by T cells and re-entered germinal centers. All autoantibodies neutralized GM-CSF bioactivity, with general correlations to affinity and off-rate. The binding of certain autoantibodies was changed by point mutations in GM-CSF that reduced binding to the GM-CSF receptor. Those monoclonal autoantibodies that potently neutralize GM-CSF may be useful in treating inflammatory disease, such as rheumatoid arthritis and multiple sclerosis, cancer, and pain. PMID:23620516
Hammarström, L; Smith, C I
Lack of serum IgG2, IgA and IgE was found in a healthy male adult blood donor. No secretory IgA could be demonstrated. In vitro activation of lymphocytes did not induce IgA secreting cells although no class specific suppressor cells could be found. Normal or slightly subnormal titres to a variety of bacterial and viral antigens were demonstrated whereas anti-carbohydrate antibodies (anti-teichoic acid, anti-dextran and anti-pneumococcal polysaccharide) were virtually absent. Isoagglutinins and heteroagglutinins were present in somewhat lower concentrations than normal. PMID:6189654
Serrano, Manuel; Martínez-Flores, José A; Pérez, Dolores; García, Florencio; Cabrera-Marante, Oscar; Pleguezuelo, Daniel E; Paz-Artal, Estela; Morales, José M; González, Esther; Serrano, Antonio
Background -Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis and/or gestational morbidity in patients with antiphospholipid autoantibodies (aPL). Predictive value of the presence of aPL is low and new markers are necessary to identify aPL carriers at higher risk and take preventive measures on them.The presence of circulating immune complexes of IgA bound to Beta2-glycoprotein-I (B2A-CIC) has been associated with occurrence of acute thrombotic events (TEV). In this work we study its possible predictive value for appearance of TEV in patients who are going to undergo transplant surgery, a well-known trigger of TEV in aPL carriers 94. Methods -We performed a follow-up study based on the Magnum 12+12 Cohort of patients who received a kidney transplant (N=1339). Three groups were established: Group-1 patients positive for IgA anti Beta2-glycoprotein-I (B2GP1) and B2A-CIC (N=125). Group-2 only positive for IgA anti B2GP1 (N=240). Control-group: negative for IgA anti B2GP1 (N=974). Levels of autoantibodies and B2A-CIC were quantified immediately before the transplant surgery and patients were followed-up for six months. Results -In group-1, 46.4% of patients suffer any type of thrombosis versus 10.4% in group-2 (p<0.001) and 8.6% in control-group (p<0.001). Incidence of graft thrombosis in group-1 (31.2%) was significantly higher than that observed in group-2 (3.3%, p<0.001) and control-group (2.6%, p<0.001). In a multivariate analysis, presence of B2A-CIC was an independent variable to suffer any type of post-transplant thrombosis (Hazard-ratio:6.72; 95% CI:4.81-9.37) and, prominently, for graft thrombosis (Hazard-ratio:14.75; 95% CI:9.11-23.89). No significant differences were found between B2A-CIC negative and control-group patients. Conclusions -Presence of B2A-CIC is a predictor of TEV. Patients positive for IgA anti-B2GP1 only are at risk of suffering thrombosis if they are B2A-CIC positive. If they are B2A-CIC negative patients, they have
Moldoveanu, Z; Wyatt, R J; Lee, J Y; Tomana, M; Julian, B A; Mestecky, J; Huang, W-Q; Anreddy, S R; Hall, S; Hastings, M C; Lau, K K; Cook, W J; Novak, J
Immunoglobulin A (IgA) nephropathy is the most prevalent form of glomerulonephritis worldwide. A renal biopsy is required for an accurate diagnosis, as no convenient biomarker is currently available. We developed a serological test based upon the observation that this nephropathy is characterized by undergalactosylated IgA1 in the circulation and in mesangial immune deposits. In the absence of galactose, the terminal saccharide of O-linked chains in the hinge region of IgA1 is terminal or sialylated N-acetylgalactosamine. A lectin from Helix aspersa, recognizing N-acetylgalactosamine, was used to develop an enzyme-linked immunosorbent assay that measures galactose-deficient IgA1 in serum. The median serum lectin-binding IgA1 level was significantly higher for 153 Caucasian adult patients with IgA nephropathy without progression to end-stage renal disease as compared with that for 150 healthy Caucasian adult controls. As the lectin-binding IgA1 levels for the controls were not normally distributed, the 90th percentile was used for determination of significant elevation. Using a value of 1076 U/ml as the upper limit of normal, 117 of the 153 patients with IgA nephropathy had an elevated serum lectin-binding IgA1 level. The sensitivity as a diagnostic test was 76.5%, with specificity 94%; the positive predictive value was 88.6% and the negative predictive value was 78.9%. We conclude that this lectin-binding assay may have potential as a noninvasive diagnostic test for IgA nephropathy.
Nagy, J; Brasch, H; Süle, T; Hámori, A; Deák, G; Ambrus, M
Renal biopsy specimens from 204 patients with glomerulonephritis or nephrotic syndrome have been studied. In ten of the patients not suffering from acute poststreptococcal glomerulonephritis, systemic lupus erythematosus or Schönlein-Henoch syndrome, diffuse, selective mesangial IgA deposition was observed. Clinically, persistent microscopic haematuria, mild proteinuria and, except in one patient, normal renal function were found. Light microscopically the histological picture was dominated by a diffuse or focal increase in volume of the mesangial matrix, and mild mesangial cell proliferation. Exceptionally, there was also crescent formation. Immunofluorescence revealed large IgA, IgG and C3 deposits, as well as small IgM and fibrinogen deposits in the mesangial glomeruli. The authors' assumption that immunocomplexes containing a secretory component might be implicated in the pathomechanism of Berger's disease, could not be proved.
Terasaka, Tomohiro; Uchida, Haruhito A; Umebayashi, Ryoko; Tsukamoto, Keiko; Tanaka, Keiko; Kitagawa, Masashi; Sugiyama, Hitoshi; Tanioka, Hiroaki; Wada, Jun
A link between IgA nephropathy and Crohn's disease has recently been reported. Other researchers hypothesize that intestine-derived IgA complexes deposit in glomerular mesangial cells, eliciting IgA nephropathy. Intestinal mucosal plasma cells mainly secrete IgA2. Nevertheless, IgA1 deposition is strongly implicated as being the primary cause of IgA nephropathy. A 46-year-old Japanese man developed IgA nephropathy 29 years ago, following tonsillectomy. As a result, a normal urinalysis was obtained. The patient previously suffered Crohn's disease followed by urinary occult blood and proteinuria six years ago. Exacerbation of IgA nephropathy was highly suspected. Therefore a renal biopsy was performed. A diagnosis of exacerbation of IgA nephropathy with mesangial cell proliferation and fibrotic cellular crescent was based upon the pathological findings. The patient exhibited a positive clinical course and eventually achieved a remission with immunosuppressive therapy including prednisolone treatment. Immunostaining for the detection of IgA subtypes was performed on both of his kidney and excised ileum. The results revealed IgA1 and IgA2 deposition by submucosal cells in intestine. Furthermore, IgA1 deposition of mesangial areas in the patient's kidney, indicated an association of IgA1 with the exacerbation of IgA nephropathy. This case represents the possibility that the intestine-derived IgA1 can be the origin of galactose-deficient IgA which is known to cause IgA nephropathy exacerbation.
One hundred kidneys from 100 non-selected autopsy cases without any overt renal disease were examined by immunofluorescence to reveal the incidences and features of cases with clinically latent glomerular IgA deposits. Glomerular IgA deposits were found in 10 cases (10.0%), consisting of 4 with liver cirrhosis and 6 with other diseases. IgA deposition was observed in 4 of 13 cirrhotic patients (30.8%), 3 of 15 patients with gastrointestinal carcinoma (20.0%), one of 11 patients with cardiovascular disease (9.1%), one of 3 patients with fulminant hepatitis (33.3%), and one of 21 patients with broncho-pulmonary disease (4.8%). Light microscopy showed minor glomerular abnormalities in all non-cirrhotic cases with IgA deposits except in one case. By contrast, variable significant glomerular lesions were found in the cirrhotic cases with IgA deposits, for example mesangial proliferation and circumferential mesangial inter-position. Excluding 13 cases with liver cirrhosis, the results of urinalysis at the time of admission were available for the study in 55 of 87 cases. Forty-four of 55 cases showed normal urinalysis. Glomerular IgA deposition was found in 4 cases (9.1%) of 44 with normal urinalysis. It may be said that IgA deposition without clinical evidence of nephropathy occurred even in a normal population with an incidence of about 10%.
Leong, Ka Wai
The roles of human serum IgA, in contrast to that of mucosal IgA, are relatively unexplored. Previous studies have shown that IgA mediates either pro- or anti-inflammatory effects in innate immune cells. Serum IgA has been shown to interact with many proteins and glycoproteins of which the functions and mechanisms are not fully characterized. Here, we present fresh perspectives into the roles of serum IgA, describing novel IgA–protein interactions, the importance of its glycosylation status in normal functions, and the plausible role of IgA as a driver and regulator of autoimmune diseases/immune overactivation. Other potential roles, including the regulation of cytokines, effector cell function, and homeostasis, are considered in view of the maintenance of immune function. We anticipate future research to uncover new anti-inflammatory or pro-inflammatory roles of human serum IgA in immune functions and dysfunctions, with implications on systemic lupus erythematosus (SLE). PMID:25188736
Linear immunoglobulin A bullous dermatosis is a rare autoimmune mucocutaneous disorder caused by immunoglobulin A autoantibodies produced against several different antigens in the basement membrane zone. Clinically, it is characterized by tense vesicles or bullae, which on histopathological exam demonstrate subepidermal blister with a predominantly neutrophilic infiltrate. A smooth, linear pattern of immunoglobulin A deposition in the basement membrane zone on direct immunofluorescence is considered the gold standard for establishing a diagnosis. Treatment consists of dapsone or sulfapyridine. The authors report a 60-year-old woman who presented with pruritic erythematous patches and plaques on her trunk, back, and legs without blisters, who was diagnosed with eczema for several months with no response to prior treatments. A biopsy was performed, which was consistent with linear immunoglobulin A bullous dermatosis and later confirmed by direct immunofluorescence studies. The authors present this case to increase awareness of this rare disease, which could manifest in a nonclassical, nonblistering fashion. PMID:26557220
Simplex and multiplex families with IgA nephropathy (IgAN) have been reported from several ethnic backgrounds, providing the strongest evidence of a role for genetic factors in pathogenesis of IgAN. From a phenotypic point of view, familial and sporadic IgAN cannot be differentiated, and the main clinical and histological features are similar. Traditionally, the case-control study design was employed to identify associations between particular candidate genes, for example, HLA antigens the uteroglobin gene and IgAN, giving conflicting results. Recently, a different approach, using linkage analysis, was undertaken by geneticists at Yale University. A 10-cM genome-wide screen was performed in 30 multiplex IgAN pedigrees, and one locus was mapped (IGAN-1) on chromosome 6q22-23. Future study will be focused on the identification of the gene underlying IGAN-1. This will enable us to understand the molecular pathogenetic basis of IgAN.
Stanca, Carmen M; Aloman, Costica; Fiel, Maria Isabel; Raja, Kaiser; Uskudar, Oguz; Florman, Sander; Schiano, Thomas D
Little is known about autoantibody pattern in liver transplantation (LT). The aim of the study was to examine autoantibodies (AAB) and immunoglobulins in patients with end-stage liver disease before and after LT. Patients with LT who underwent post-LT biopsies between 10/2008 and 8/2011 were enrolled. AAB were assessed at the time of LT and liver biopsy. Demographics, serum immunoglobulins, AAB, and liver histology (explant, post-LT biopsies) were analyzed. Two hundred and twenty patients (M/F 143/77; age at LT 54 (19-73)) were included; AAB and immunoglobulins were evaluated in 76 patients. Length of follow-up from LT was 285 (30-1462) days. Sixty-one percent of patients had hepatitis C (HCV); 83% developed recurrent HCV. A significant decrease in IgG, IgA, IgM (p < 0.001 each), anticardiolipin antibodies IgG and IgM (p = 0.02), and beta-2 microglobulin (p = 0.004) was observed post-LT. HCV patients had higher IgG (p = 0.005), rheumatoid factor (p = 0.044) before LT; elevated IgM was associated with increased inflammation in the explant (p = 0.007). Lower IgG levels and antismooth muscle antibodies were present before LT in a higher percentage in patients who would develop recurrent HCV (p = 0.004, p = 0.077, respectively). In conclusion, AAB change significantly after LT and have a different pattern in HCV. Some immunological markers are associated with HCV recurrence and advanced inflammation on explant.
Liles, Campbell; Li, Hongliang; Veitla, Vineet; Liles, Jonathan T; Murphy, Taylor A; Cunningham, Madeleine W; Yu, Xichun; Kem, David C
Activating autoantibodies to the angiotensin type 1 receptor (AT1R) are associated with hypertensive disorders. The angiotensin type 2 receptor (AT2R) is known to counter-regulate the actions of AT1R. We investigated whether AT2R autoantibodies produced in immunized rabbits will activate AT2R and suppress the vasopressor responses to angiotensin II and AT1R-activating autoantibodies. Five rabbits immunized with a peptide corresponding to the second extracellular loop of AT2R developed high AT2R antibody titers. Rabbit anti-AT2R sera failed to directly dilate isolated rat cremaster arterioles; however, when co-perfused with angiotensin II or AT1R-activating autoantibodies, the anti-AT2R sera significantly inhibited their contractile effects. Rabbit anti-AT2R sera recognized a predominant sequence near the N-terminus of the AT2R second extracellular loop. A decoy peptide based on this sequence effectively reversed the opposing effect of the anti-AT2R sera on angiotensin II-induced contraction of rat cremaster arterioles. A similar blockade of the anti-AT2R sera effect was observed with the AT2R antagonist PD 123319 and the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one. Rabbit anti-AT2R sera reacted specifically with AT2R. No cross-reactivity with AT1R was observed. Blood pressure did not change in immunized animals. However, the pressor responses to incremental angiotensin II infusions were blunted in immunized animals. Thirteen subjects with primary aldosteronism demonstrated increased AT2R autoantibody levels compared with normal controls. In conclusion, AT2R autoantibodies produced in immunized rabbits have the ability to activate AT2R and counteract the AT1R-mediated vasoconstriction. These autoantibodies provide useful and selective tools for the study of their roles in blood pressure regulation and possible therapeutic intervention. © 2015 American Heart Association, Inc.
Jost, Sheridan A; Tseng, Lin-Chiang; Matthews, Loderick A; Vasquez, Rebecca; Zhang, Song; Yancey, Kim B; Chong, Benjamin F
IgG antinuclear antibodies (ANAs) are elevated in patients with systemic lupus erythematosus (SLE) compared with patients with discoid lupus erythematosus (DLE). To provide an expanded immunologic view of circulating ANAs in lupus patients, we compared the expressions of IgG, IgM, and IgA ANAs in DLE and SLE patients. In this cross-sectional study, sera from age-, gender-, and ethnic-matched SLE (N = 35), DLE (N = 23), and normal patients (N = 22) were tested for IgG, IgM, and IgA ANAs using enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) with monkey esophagus as substrate. ELISAs showed elevated levels of IgG ANA, IgM ANA, and IgG/IgM ANA ratios in SLE patients compared with DLE and normal patients. IgA ANA expression was higher in SLE and DLE patients versus normal patients. IIF studies showed higher percentages of patients positive for IgG, IgM, and IgA ANAs in the SLE group. Higher IgG/IgM ANA ratios in SLE than DLE show enhanced class-switching and a more sustained humoral response in SLE. They also suggest a potential connection of IgM ANAs with disease containment.
Liu, Haiying; Norman, Gary L; Shums, Zakera; Worman, Howard J; Krawitt, Edward L; Bizzaro, Nicola; Vergani, Diego; Bogdanos, Dimitrios P; Dalekos, George N; Milkiewicz, Piotr; Czaja, Albert J; Heathcote, E Jenny; Hirschfield, Gideon M; Tan, Eng M; Miyachi, Kiyomitsu; Bignotto, Monica; Battezzati, Pier Maria; Lleo, Ana; Leung, Patrick S; Podda, Mauro; Gershwin, M Eric; Invernizzi, Pietro
A dual isotype (IgG, IgA) enzyme-linked immunosorbent assay (ELISA) designed to provide enhanced detection of primary biliary cirrhosis (PBC)-specific autoantibodies against both major mitochondrial and nuclear antigens has been developed and recently become commercially available. The assay (PBC Screen) simultaneously detects IgG and IgA autoantibodies to the immunodominant portions of the 3 major mitochondrial (MIT3) and nuclear (gp210, and sp100) antigens. The aim of this study was to compare the performance of the PBC Screen to the combined performance obtained with individual IgG ELISAs to MIT3, gp210, and sp100 on a large group of selected patients from multiple centers. A total of 1175 patients with PBC and 1232 subjects without PBC were evaluated. Non-PBC groups included healthy controls (624) as well as individuals with autoimmune hepatitis (281), primary sclerosing cholangitis (77), viral hepatitis (91 hepatitis B and 98 hepatitis C), other liver diseases (31), and other infectious or autoimmune diseases (30). The PBC Screen at the receiver operator characteristic optimized cutoff of 27.8 units, had an overall sensitivity of 83.8%, specificity of 94.7% and area under curve of 0.9212. This was similar to the specificity of 96.1% obtained by the combined results of individual MIT3, sp100, and gp210 IgG ELISAs (kappa index at 0.898). Of the 253 PBC patients without AMA detectable by immunofluorescence, 113 (44.7%) were interpreted as positive for PBC-specific autoantibodies. In conclusion, the PBC Screen is an appropriate first-line test for the diagnosis of PBC, including for patients negative for markers assessed using conventional methods. Copyright © 2010 Elsevier Ltd. All rights reserved.
Sotoodian, Bahman; Robert, Janet; Mahmood, Muhammad N; Yacyshyn, Elaine
IgA vasculitis is a small-vessel vasculitis caused by deposition of IgA antibodies in tissues. IgA nephropathy and IgAV have long been considered related conditions. To assess the prevalence and implications of new-onset Henoch-Schönlein purpura (HSP) after renal transplant in patients with underlying IgA nephropathy. The PubMed database was searched for keywords such as IgAV, IgA vasculitis, Henoch-Schönlein purpura, HSP, IgA nephropathy, and renal transplant. Two cases of new-onset IgA vasculitis post-renal transplant after stopping the prednisone or receiving seasonal influenza vaccine have been reported. We report the case of new-onset IgA cutaneous vasculitis in a renal transplant patient with IgA nephropathy after reduction in his prednisone dosage. The new development of cutaneous IgA vasculitis is unusual in renal transplant patients with IgA nephropathy. Despite these patients' being immunosuppressed, the presence of IgA vasculitis could signal the recurrence of IgA nephropathy. © The Author(s) 2015.
Kirkman, Nikki J.; Libbey, Jane E.; Sweeten, Thayne L.; Coon, Hilary H.; Miller, Judith N.; Stevenson, Edward K.; Lainhart, Janet E.; McMahon, William M.; Fujinami, Robert S.
Controversy exists over the role of autoantibodies to central nervous system antigens in autism and Tourette Syndrome. We investigated plasma autoantibody titers to glial fibrillary acidic protein (GFAP) in children with classic onset (33) and regressive onset (26) autism, controls (25, healthy age- and gender-matched) and individuals with…
Margari, Francesco; Petruzzelli, Maria Giuseppina; Mianulli, Rossana; Campa, Maria Gloria; Pastore, Adriana; Tampoia, Marilina
In recent years, an inflammatory autoimmune process, autoantibodies mediated, has been porposed as having a role in the development of different psychiatric disorders. The aim of this study was to assay organ-specific and non organ-specific circulating autoantibodies in schizophrenia, mood disorders and healthy controls; among organ-specific autoantibodies we focused on different fluorescence patterns of anti-brain autoantibodies against rat and monkey's sections of hippocampus, hypothalamus and cerebellum. Serum samples from 50 acutelly ill patients (30 schizophrenia and 20 mood disorders) and from 20 healthy controls were collected. Autoantibodies were assayed by indirect immunofluorescence, enzyme linked immunosorbent assay and chemiluminescence immunoassay. We found a significant difference for circulating autoantibodies to hypothalamus, hippocampus and cerebellum and for anti-nuclear autoantibodies in both schizophrenia and mood disorders when compared to the control group. Referring to the two groups of patients only, circulating antibodies anti-hypothalamus were found significant higher in mood disorders rather than in schizophrenia, with specific regard to nuclear and cytoplasmic staining of the neurons. These data suggest an aspecific diffuse brain involvement of anti-brain autoantibodies in acute phases of schizophrenia and mood disorders. The greater involvement of the hypothalamus in mood disorders highlights the close relationship between autoimmunity, hypothalamic-pituitary-adrenal axis and affective disorders.
Kirkman, Nikki J.; Libbey, Jane E.; Sweeten, Thayne L.; Coon, Hilary H.; Miller, Judith N.; Stevenson, Edward K.; Lainhart, Janet E.; McMahon, William M.; Fujinami, Robert S.
Controversy exists over the role of autoantibodies to central nervous system antigens in autism and Tourette Syndrome. We investigated plasma autoantibody titers to glial fibrillary acidic protein (GFAP) in children with classic onset (33) and regressive onset (26) autism, controls (25, healthy age- and gender-matched) and individuals with…
Yu, Liping; Miao, Dongmei; Scrimgeour, Laura; Johnson, Kelly; Rewers, Marian; Eisenbarth, George S
A subset of children develops persistent insulin autoantibodies (IAA; almost always as the only islet autoantibody) without evidence of progression to diabetes. The aim of the current study was the development and characterization of the performance of a nonradioactive fluid phase IAA assay in relation to standard IAA radioassay. We developed a nonradioactive IAA assay where bivalent IAA cross-link two insulin moieties in a fluid phase. The serum samples positive for anti-islet autoantibodies from 150 newly diagnosed patients with diabetes (Barbara Davis Center plus Diabetes Autoantibody Standardization Program [DASP] workshop) and 70 prediabetic subjects who were followed to diabetes were studied. In addition, sequential samples from 64 nondiabetic subjects who were persistently IAA(+) were analyzed. With 99th percentile of specificity, the new assay with the technology from Meso Scale Discovery Company (MSD-IAA) detects as positive 61% (61 of 100) of new-onset patients and 80% (56 of 70) of prediabetic patients compared with our current fluid phase micro-IAA radioassay (mIAA; 44 and 74%, respectively). In addition, MSD-IAA demonstrated better sensitivity than our mIAA from blinded DASP workshop (68 vs. 56% with the same 99% specificity). Of 64 IAA(+) nondiabetic subjects, 25% (8 of 32) who had only IAA and thus the low risk for progression to diabetes were positive with MSD-IAA assay. In contrast, 100% (32 of 32) high-risk children (IAA plus other islet autoantibodies) were positive with MSD-IAA. The IAA detectable by radioassay, but not MSD-IAA, were usually of lower affinity compared with the IAA of the high-risk children. These data suggest that a subset of IAA with current radioassay (not MSD-IAA) represents biologic false positives in terms of autoimmunity leading to diabetes. We hypothesize that factors related to the mechanism of loss of tolerance leading to diabetes determine high affinity and MSD-IAA reactivity.
Phillips, J. C.
The most cost-effective blood-based, noninvasive molecular early cancer biomarkers are based on p53 epitopes and MUC1 tandem repeats. Here we use dimensionally compressed bioinformatic fractal scaling analysis to compare the two distinct and comparable probes, which examine different sections of the autoantibody population, achieving combined sensitivities of order 50%. We explain the experimental observation that glycosylation does not enhance, and can depress, the sensitivity of MUC1 tandem repeat biomarkers. We propose a possible supplementary MUC1 epitope in the SEA region outside the tandem repeats.
Vermeire, Severine; Vermeulen, Nathalie; Van Assche, Gert; Bossuyt, Xavier; Rutgeerts, Paul
Patients who have inflammatory bowel diseases (IBD) express strong antibody responses to a variety of epitopes. A number of (auto)antibodies have been described in patients who have Crohn's disease or ulcerative colitis. These markers reflect a loss of tolerance toward bacterial and fungal flora and have been studied for their clinical value in IBD patients. However, currently, they have no place in the diagnostic work up. Their real promise may lie in their use as surrogate markers of complicated aggressive disease as shown in various retrospective studies, but prospective data are lacking.
Background Early appearance of antibodies specific for native human type II collagen (anti-CII) characterizes an early inflammatory and destructive phenotype in adults with rheumatoid arthritis (RA). The objective of this study was to investigate the occurrence of anti-CII, IgM RF, IgA RF and anti-CCP in serum samples obtained early after diagnosis, and to relate the occurrence of autoantibodies to outcome after eight years of disease in children with juvenile idiopathic arthritis (JIA). Methods The Nordic JIA database prospectively included JIA patients followed for eight years with data on remission and joint damage. From this database, serum samples collected from 192 patients, at a median of four months after disease onset, were analysed for IgG anti-CII, IgM RF, IgA RF and IgG anti-CCP. Joint damage was assessed based on Juvenile Arthritis Damage Index for Articular damage (JADI-A), a validated clinical instrument for joint damage. Results Elevated serum levels of anti-CII occurred in 3.1%, IgM RF in 3.6%, IgA RF in 3.1% and anti-CCP in 2.6% of the patients. Occurrence of RF and anti-CCP did to some extent overlap, but rarely with anti-CII. The polyarticular and oligoarticular extended categories were overrepresented in patients with two or more autoantibodies. Anti-CII occurred in younger children, usually without overlap with the other autoantibodies and was associated with high levels of C-reactive protein (CRP) early in the disease course. All four autoantibodies were significantly associated with joint damage, but not with active disease at the eight-year follow up. Conclusions Anti-CII, anti-CCP, IgA RF and IgM RF detected early in the disease course predicted joint damage when assessed after eight years of disease. The role of anti-CII in JIA should be further studied. PMID:24944545
Matsushita, Y; Shimada, Y; Kawara, S; Takehara, K; Sato, S
Psoriasis is believed to be a T cell-mediated autoimmune disease, but also exhibits autoantibody production. Calpastatin is an endogenous inhibitor of calpain, a ubiquitous protease that regulates inflammatory processes. Anti-calpastatin autoantibody was first identified as an autoantibody specific to rheumatoid arthritis, but has been also detected in other autoimmune diseases. In this study, we examined the presence and levels of anti-calpastatin antibody in 77 psoriasis patients by enzyme-linked immunosorbent assay. Compared with normal controls, psoriasis patients exhibited significantly elevated IgG anti-calpastatin antibody levels that were similar to those found in rheumatoid arthritis patients. Remarkably, IgG anti-calpastatin autoantibody in sera from psoriasis patients inhibited calpastatin activity. Calpain II expression was up-regulated in psoriasis skin lesions compared with normal skin while calpastatin expression was normal. The results of this study reveal the presence of anti-calpastatin autoantibody in psoriasis. PMID:15654835
Gerfaud-Valentin, M; Ahmad, K; Piegay, F; Fabien, N; Raphanel, B; Cordier, J-F; Cottin, V
Amyopathic dermatomyositis associated with anti-MDA5 autoantibodies is a rare and very recently described clinical entity. A 58-year-old woman was admitted with subacute onset of dyspnea (NYHA class IV) associated with cough, oligoarthritis of the wrists, myalgia and intermittent fever. Examination demonstrated skin lesions with heliotrope rash, Gottron's papules, "mechanics hands", and basal inspiratory crackles on lung auscultation. Pulmonary function tests showed a restrictive ventilatory defect, with decreased carbon monoxide diffusion capacity and marked hypoxemia (PaO2 61 mmHg). The chest high-resolution computed tomography appearances were consistent with organizing pneumonia. Bronchoalveolar lavage differential cell count demonstrated 22 % neutrophils. Serum creatine kinase and electromyography were normal ; the serum ferritin level was elevated. Antinuclear antibodies were present and anti-MDA5 autoantibodies were identified. Significant improvement was obtained with systemic corticosteroids, later converted to mycophenolate mofetil as a steroid-sparing agent. Amyopathic dermatomyositis associated with anti-MDA5 autoantibodies shares some characteristics with those associated with anti-synthetase antibodies. Muscular involvement may be mild or absent. Early diagnosis and treatment may improve outcome. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.
Betterle, C; Caretto, A; Zeviani, M; Pedini, B; Salviati, C
We studied 32 patients with idiopathic hypoparathyroidism (IHP), 19 patients with organ-specific autoimmune diseases (OSAD) without IHP, 50 normal controls and a known serum with anti-mitochondrial autoantibodies (AMA). Patients' sera were tested by the classical indirect immunofluorescent technique and by the indirect immunofluorescent complement fixation technique on unfixed cryostat sections of normal human parathyroid, pancreas, thyroid, stomach, kidney, and rat kidney. Five out of 32 patients with IHP, three out of 19 patients with OSAD without IHP and one out of 50 normal controls revealed a bright reactivity against oxyphil cells and a weak reactivity against chief cells of normal parathyroid. These sera also brightly reacted with mitochondria-rich cells and weakly with the remaining cells of only human tissues. The absorption of positive sera with human mitochondria completely abolished this positivity but the absorption with rat mitochondria failed to prevent this reaction. This reactivity was due to an anti-human mitochondrial autoantibody (AHMA) of IgG class. By non-competitive ELISA and Western blot we also demonstrated that every AHMA-positive serum mainly reacted against a human mitochondrial membrane-bound protein of approximate mol. wt. of 46 kd, while the AMA-positive serum reacted against different mitochondrial antigens. The present study shows that a specific parathyroid autoantibody was not detectable in patients with IHP. Images Fig. 3 PMID:3910313
Yabuki, Akira; Shimokawa Miyama, Takako; Kohyama, Moeko; Yamato, Osamu
Immunoglobulin (Ig) A nephropathy is a rare form of canine glomerular disease. This report describes a case of canine IgA nephropathy showing characteristics typical of human IgA nephropathy. An 8-year-old, spayed female Miniature Dachshund showed persistent severe proteinuria without azotemia. She was receiving long-term glucocorticoid therapy due to chronic gastritis and an intra-abdominal suture granuloma. A renal biopsy demonstrated mesangial proliferative glomerulonephritis with predominantly mesangial IgA deposition and electron-dense deposits in the paramesangium. These findings closely resembled those of human IgA nephropathy. Glucocorticoid treatment was discontinued, and the angiotensin-converting enzyme inhibitor enalapril was administrated as an antiproteinuric agent. The proteinuria subsequently went into remission, and the patient has maintained good condition without recurrence.
Khan, Naheed; Robson, Amanda J; Worthington, Judith E; Martin, Susan
We have developed a flow cytometry-based screening method using FlowPRA (One Lambda) human leukocyte antigen (HLA) class I panel beads and FlowPRA (One Lambda) HLA class I specificity beads for the detection and definition of immunoglobulin (Ig)M HLA-specific antibodies in the presence of IgM autoantibodies. Forty-six autoantibody-positive patients who were on the waiting list for a renal transplant (56 sera) were tested in parallel with FlowPRA (One Lambda) HLA class I beads and FlowPRA (One Lambda) control beads. Sera that were positive for IgM HLA class I antibodies were subsequently tested with FlowPRA HLA class I specificity beads to determine the HLA specificities. Thirteen of the 46 patients were positive for IgM HLA class I-specific antibodies. Eleven of the 13 had previous failed transplants and 2 were awaiting a primary transplant. For 9 of the 13 positive patients, IgM HLA class I specificities were defined. We have demonstrated the presence of IgM HLA-specific antibodies in patients with IgM autoantibodies. This study demonstrates the value of FlowPRA HLA class I panel and specificity beads for the detection and definition of IgM HLA class I-specific antibodies.
D'Arco, Christina; Dattwyler, Raymond J; Arnaboldi, Paul M
The laboratory diagnosis of Lyme disease is currently dependent on the detection of IgM and IgG antibodies against Borrelia burgdorferi, the causative agent of the disease. The significance of serum IgA against B. burgdorferi remains unclear. The production of intrathecal IgA has been noted in patients with the late Lyme disease manifestation, neuroborreliosis, but production of antigen-specific IgA during early disease has not been evaluated. In the current study, we assessed serum IgA binding to the B. burgdorferi peptide antigens, C6, the target of the FDA-cleared C6 EIA, and FlaB(211-223)-modVlsE(275-291), a peptide containing a Borrelia flagellin epitope linked to a modified VlsE sequence, in patients with early and late Lyme disease. Specific IgA was detected in 59 of 152 serum samples (38.8%) from early Lyme disease patients. Approximately 50% of early Lyme disease patients who were seropositive for peptide-specific IgM and/or IgG were also seropositive for peptide-specific IgA. In a subpopulation of patients, high peptide-specific IgA could be correlated with disseminated disease, defined as multiple erythema migrans lesions, and neurological disease complications. These results suggest that there may be an association between elevated levels of antigen-specific IgA and particular disease manifestations in some patients with early Lyme disease. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Sennekamp, J; Morr, H; Behr, J
Up to now only 3 cases of extrinsic allergic alveolitis (hypersensitivity pneumonitis) with IgA deficiency have been published worldwide. We had the opportunity to detect two additional cases which will be presented here. Summarizing all cases IgA deficiency is a risk factor for a severe course of the disease and an increased susceptibility to acquire allergic alveolitis by low dose antigen exposure.
Satoh, Minoru; Chan, Jason Y F; Ceribelli, Angela; Vazquez del-Mercado, Monica; Chan, Edward K L
Like many other classical autoantibodies in systemic rheumatic diseases, anti-Su antibodies were originally defined by the double immunodiffusion assay in the early 80s. However, despite its high prevalence, only a few reports on anti-Su were published in the following years and the progress in characterizing the target antigens and clinical significance was slow, probably due to its inconsistent or poor reactivity in other standard immunoassays. In 2006 the target antigen was identified as the microRNA (miRNA)-binding protein Argonaute 2 (Ago2). Ago2 is a key component of the RNA-induced silencing complex enriched in cytoplasmic foci called GW bodies. Due to preferential reactivity of human autoantibodies with native antigens, immunoprecipitation is the only method to reliably detect anti-Su/Ago2 antibodies. Anti-Su/Ago2 does not appear to have disease specificity since it is found in 10-20% of patients with various rheumatic diseases, including systemic lupus erythematosus, scleroderma, polymyositis/dermatomyositis, and Sjögren's syndrome, as well as apparently healthy individuals at lower prevalence. The clinical significance and the mechanism of production of anti-Su/Ago2 remains to be clarified.
Phillips, J. C.
There is an urgent need for economical blood based, noninvasive molecular biomarkers to assist in the detection and diagnosis of cancers in a cost-effective manner at an early stage, when curative interventions are still possible. Serum autoantibodies are attractive biomarkers for early cancer detection, but their development has been hindered by the punctuated genetic nature of the ten million known cancer mutations. A landmark study of 50,000 patients (Pedersen et al., 2013) showed that a few p53 15-mer epitopes are much more sensitive colon cancer biomarkers than p53, which in turn is a more sensitive cancer biomarker than any other protein. The function of p53 as a nearly universal "tumor suppressor" is well established, because of its strong immunogenicity in terms of not only antibody recruitment, but also stimulation of autoantibodies. Here we examine dimensionally compressed bioinformatic fractal scaling analysis for identifying the few sensitive epitopes from the p53 amino acid sequence, and show how it could be used for early cancer detection (ECD). We trim 15-mers to 7-mers, and identify specific 7-mers from other species that could be more sensitive to aggressive human cancers, such as liver cancer. Our results could provide a roadmap for ECD.
Cubillos, J; Lucena, A; Lucena, C; Mendoza, J C; Ruiz, H; Arango, A; Quiroga, G; Ferro, J; Lucena, E
The purpose of this study was to determine the incidence of autoantibodies in patients with no term pregnancies. Patients selected included 43 with primary infertility and 110 with a history of pregnancy loss. In the first group the incidence of antinuclear antibodies (ANA) and IgG and IgM antiphospholipid antibodies (APL) was 37.2% (p < 0.05) and 53.5% (p < 0.05), respectively. In the group of patients with a history of miscarriage, 31.8% (p < 0.05) were positive for ANA and 38.2% (p < 0.05) for APL. Controls were 35 healthy patients with proven fertility and no history of pregnancy loss or autoimmune disease. In this group the incidence of ANA was 5.7% and 11.4% for APL. The high incidence of autoantibodies found in patients with primary infertility might suggest a direct involvement of these antibodies in reproductive failure and consequently in IVF and assisted fertility procedures. The prevalence of ANA and APL has been extensively described in patients with a history of recurrent pregnancy losses (RPL). In this study we observed antibodies even after the first miscarriage. We therefore conclude that patients with a history of reproductive failure should be immunologically evaluated and treated before undergoing assisted fertilization techniques or before a new pregnancy in those cases of RPL.
Briese, V; Straube, W
The problem was to prove the significance of IgA estimations in maternal serum samples with regard to the diagnosis and the monitoring of intrauterine fetal growth retardation. IgA was estimated in serum samples from two groups of patients. The first was formed from 62 serum samples of 14 primi- and multiparae delivered from new-borns with a birth weight below the 10th centile. The second was the control group. 82 serum samples from 18 gravidae were available. The IgA estimations were carried out by means of single radial immunodiffusion according to Mancini and co-workers. The IgA values of the two groups were different considering that linear regression model was used; negative correlation between IgA and pregnancy weeks in group with retarded new-borns (y = -151,78 X + 7579,8; r = -0,39) and positive correlation of these parameters in control group (y = 73,59 X -429,38; r = 0,26). It could be that IgA is an additional parameter within placental function tests of the 3rd trimester of pregnancy.
Blutt, Sarah E.; Conner, Margaret E.
Viral gastroenteritis is one of the leading causes of diseases that kill ~2.2 million people worldwide each year. IgA is one of the major immune effector products present in the gastrointestinal tract yet its importance in protection against gastrointestinal viral infections has been difficult to prove. In part this has been due to a lack of small and large animal models in which pathogenesis of and immunity to gastrointestinal viral infections is similar to that in humans. Much of what we have learned about the role of IgA in the intestinal immune response has been obtained from experimental animal models of rotavirus infection. Rotavirus-specific intestinal IgA appears to be one of the principle effectors of long term protection against rotavirus infection. Thus, there has been a focus on understanding the immunological pathways through which this virus-specific IgA is induced during infection. In addition, the experimental animal models of rotavirus infection provide excellent systems in which new areas of research on viral-specific intestinal IgA including the long term maintenance of viral-specific IgA. PMID:24348474
Staff, Caroline; Magnusson, Carl G M; Hojjat-Farsangi, Mohammad; Mosolits, Szilvia; Liljefors, Maria; Frödin, Jan-Erik; Wahrén, Britta; Mellstedt, Håkan; Ullenhag, Gustav J
Previous clinical studies have indicated that natural IgM antibodies have the ability to induce apoptosis of tumor cells but IgE and IgA may also mediate tumor cell killing (in addition to IgG). The aim of the study was to analyse induction of IgM, IgA and IgE antibodies in patients vaccinated with the tumor associated antigen CEA. Twenty-four resected CRC patients without macroscopic disease were immunized seven times with CEA ± GM-CSF. Four different dose schedules were used over a 12-month period. IgM, IgA and IgE antibody responses against recombinant CEA were determined by ELISA. Patients were monitored immunologically for 36 months and clinically for 147 months. GM-CSF significantly augmented the anti-CEA response for all three antibody classes. Low dose of CEA tended to induce a higher IgM, IgA or IgE anti-CEA antibody response than higher. Anti-CEA IgA antibodies could lyse CEA positive tumor cells in antibody dependent cellular cytotoxicity (ADCC) as well as in complement dependent cytotoxicity (CDC). A significant correlation between survival and high IgA anti-CEA titers was noted (p = 0.02) irrespective of GM-CSF treatment. The observation that IgA anti-CEA antibodies were cytotoxic and associated with improved survival might indicate that also these antibodies may exert a clinical anti-tumor effect.
Sandin, C; Eriksson, P; Segelmark, M; Skogh, T; Kastbom, A
Circulating immunoglobulin (Ig)A class anti-neutrophil cytoplasm antibodies (ANCA) directed against proteinase 3 (PR3) have been reported in ANCA-associated vasculitis (AAV) with mucosal involvement. However, secretory IgA (SIgA) PR3-ANCA has not been reported previously. In this study we compared serum levels of SIgA PR3-ANCA and IgA PR3-ANCA with IgG PR3-ANCA in relation to disease characteristics. Among 73 patients with AAV and PR3-ANCA at diagnosis, 84% tested positive for IgG PR3-ANCA, 47% for IgA-ANCA and 36% for SIgA PR3-ANCA at the time of sampling for the present study. IgA and IgG PR3-ANCA were represented similarly among patients with different organ manifestations, i.e. upper airway, lung or kidney at time of sampling. However, SIgA PR3-ANCA was significantly less represented among patients with upper airway involvement. During active disease, the proportions of IgA PR3-ANCA and SIgA PR3-ANCA-positive patients were significantly higher compared to inactive disease. Eight patients were sampled prospectively during 24 months from onset of active disease. In these patients, IgA PR3-ANCA and SIgA PR3-ANCA turned negative more often after remission induction compared to IgG PR3-ANCA. Our findings suggest that serum IgA PR3-ANCA and SIgA PR3-ANCA are related more closely to disease activity in AAV compared to IgG PR3-ANCA. Further studies are required to reveal if this has implications for disease activity monitoring. The mean number of PR3-ANCA isotypes increased along with disease activity, suggesting a global B cell activation during active disease. © 2016 British Society for Immunology.
Suzuki, Hitoshi; Allegri, Landino; Suzuki, Yusuke; Hall, Stacy; Moldoveanu, Zina; Wyatt, Robert J; Novak, Jan; Julian, Bruce A
In patients with IgA nephropathy (IgAN), circulatory IgA1 and IgA1 in mesangial deposits contain elevated amounts of galactose-deficient IgA1 (Gd-IgA1). We hypothesized that a fraction of Gd-IgA1 from the glomerular deposits and/or circulation may be excreted into the urine and thus represent a disease-specific biomarker. Levels of urinary IgA and Gd-IgA1 were determined in 207 patients with IgAN, 205 patients with other renal diseases, and 57 healthy controls, recruited in USA, Japan, and Italy. Urinary IgA was similarly elevated in patients with IgAN and renal-disease controls compared with healthy controls. However, urinary Gd-IgA1 levels were higher in patients with IgAN (IgAN, 28.0 ± 17.9; disease controls, 20.6 ± 17.4 units/mg urinary creatinine; P < 0.0001). Lectin western blotting data confirmed these results. In IgAN patients, levels of urinary Gd-IgA1 correlated with proteinuria (P < 0.001). When we purified IgA from serum and urine of an IgAN patient, the relative proportion of Gd-IgA1 to total IgA1 was higher in the urine compared with serum, suggesting selective excretion of Gd-IgA1 in IgAN. In summary, urinary excretion of Gd-IgA1 was elevated in patients with IgAN and the urinary Gd-IgA1 levels correlated with proteinuria. Urinary Gd-IgA1 may thus represent a disease-specific biomarker of IgAN.
Allegri, Landino; Hall, Stacy; Wyatt, Robert J.
In patients with IgA nephropathy (IgAN), circulatory IgA1 and IgA1 in mesangial deposits contain elevated amounts of galactose-deficient IgA1 (Gd-IgA1). We hypothesized that a fraction of Gd-IgA1 from the glomerular deposits and/or circulation may be excreted into the urine and thus represent a disease-specific biomarker. Levels of urinary IgA and Gd-IgA1 were determined in 207 patients with IgAN, 205 patients with other renal diseases, and 57 healthy controls, recruited in USA, Japan, and Italy. Urinary IgA was similarly elevated in patients with IgAN and renal-disease controls compared with healthy controls. However, urinary Gd-IgA1 levels were higher in patients with IgAN (IgAN, 28.0 ± 17.9; disease controls, 20.6 ± 17.4 units/mg urinary creatinine; P < 0.0001). Lectin western blotting data confirmed these results. In IgAN patients, levels of urinary Gd-IgA1 correlated with proteinuria (P < 0.001). When we purified IgA from serum and urine of an IgAN patient, the relative proportion of Gd-IgA1 to total IgA1 was higher in the urine compared with serum, suggesting selective excretion of Gd-IgA1 in IgAN. In summary, urinary excretion of Gd-IgA1 was elevated in patients with IgAN and the urinary Gd-IgA1 levels correlated with proteinuria. Urinary Gd-IgA1 may thus represent a disease-specific biomarker of IgAN. PMID:27647947
Lin, Ya-Lin; Ip, Peng-Peng; Liao, Fang
Intestinal immunity exists as a complex relationship among immune cells, epithelial cells, and microbiota. CCR6 and its ligand–CCL20 are highly expressed in intestinal mucosal tissues, such as Peyer’s patches (PPs) and isolated lymphoid follicles (ILFs). In this study, we investigated the role of the CCR6–CCL20 axis in intestinal immunity under homeostatic conditions. CCR6 deficiency intrinsically affects germinal center reactions in PPs, leading to impairments in IgA class switching, IgA affinity, and IgA memory B cell production and positioning in PPs, suggesting an important role for CCR6 in T-cell-dependent IgA generation. CCR6 deficiency impairs the maturation of ILFs. In these follicles, group 3 innate lymphoid cells are important components and a major source of IL-22, which stimulates intestinal epithelial cells (IECs) to produce antimicrobial peptides (AMPs). We found that CCR6 deficiency reduces IL-22 production, likely due to diminished numbers of group 3 innate lymphoid cells within small-sized ILFs. The reduced IL-22 levels subsequently decrease the production of AMPs, suggesting a critical role for CCR6 in innate intestinal immunity. Finally, we found that CCR6 deficiency impairs the production of IgA and AMPs, leading to increased levels of Alcaligenes in PPs, and segmented filamentous bacteria in IECs. Thus, the CCR6–CCL20 axis plays a crucial role in maintaining intestinal symbiosis by limiting the overgrowth of mucosa-associated commensal bacteria. PMID:28744287
Atta, Ajax M; Oliveira, Isabela S; Sousa, Gabriel M; Paraná, Raymundo; Atta, Maria L Sousa
This work investigated the serum cytokine profile (IL-2, IL-4, IL-5, IL-10, IFN-gamma and BAFF) of hepatitis C virus (HCV) carriers with autoimmunity. Forty-seven HCV carriers and 28 healthy controls were evaluated. Cytokine levels were measured by ELISA. Patients and controls presented similar levels of IL-2, IL-4, IL-5, IL-10, IFN-gamma and BAFF (p>0.05). Cryoglobulinaemic HCV carriers had increased IL-2 (p=0.013), IL-5 (p=0.018) and BAFF (p=0.050). IFN-gamma level was decreased in HCV carriers with rheumatoid factor in comparison with those that were RF-seronegative (p=0.035). Patients with beta2GPI IgA antibodies when were compared with those without this autoantibody, had more serum IL-2 (p=0.009), IL-5 (p=0.018) and BAFF (p=0.039). Interleukin-2 was increased in HCV carriers with positive ANA when they were compared with ANA-seronegative carriers (p=0.044). Interleukins IL-4 and IL-10 were not associated with autoimmunity (P>0.05). In HCV carriers, IL-2 was correlated with IL-5 (p<0.0001) and IFN-gamma (p=0.015), and IL-5 with IFN-gamma (p=0.015). We concluded that the serum profile of cytokines in HCV carriers presenting autoimmune markers may be mainly represented by increased IL-2, IL-5 and BAFF.
O'Dwyer, Damien T; McElduff, Patrick; Peterson, Pärt; Perheentupa, Jaakko; Crock, Patricia A
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autosomal recessive disease due to mutations in the AIRE (AutoImmune REgulator) gene. The role of pituitary autoimmunity in APECED is not known. We determined the prevalence of pituitary autoantibodies in a cohort of 67 Finnish patients with APECED from 217 serum samples collected over 26 years by one investigator. Overall, autoantibodies to the 49 kDa cytosolic autoantigen, human pituitary enolase were detected in 39 of the 67 patients (58%). On their first sample, 25 patients had autoantibodies compared to 5 of 68 controls (chi-square, 1df=17.11, p< 0.001; OR=7.32), but subsequently 14 patients seroconverted between 10 and 53 years of age. Once seropositive, all but two of the patients maintained their positive autoantibody status, even over many years. In the current study all but 7 of the 19 patients known to have high titre anti-candidal enolase antibodies had developed autoantibodies directed against human pituitary enolase. Other pituitary autoantibody reactivities were detected against cytosolic proteins of molecular weights 40-, 45-, 60- and 105 kDa in 15%, 16%, 12% and 3% of patients respectively. Autoantibodies to pituitary enolase are markers of neuroendocrine autoimmunity but seem not to be associated with clinical hypopituitarism in APECED patients.
Szulzyk, Tomasz; Parfieniuk-Kowerda, Anna; Luto, Magdalena; Lapiński, Tadeusz Wojciech; Flisiak, Robert
Autoantigens are present in normal cells and tissues. However, in physiological conditions autoantigens pose no danger due to the phenomenon of immunologic tolerance. The loss of immunologic tolerance and following autoagression could result from the structure changes of autoantigens as an effect of the activity of chemical factors, such as acetaldehyde, which is metabolite of ethanol. The aim of the study was to evaluate of occurrence of autoantibodies in patients with alcoholic liver disease. Ninety-five patients with chronic alcoholic liver disease and 16 healthy controls were enrolled in this study. The presence of autoantibodies against liver proteins were assessed. The occurrence of studied autoantibodies was evaluated with regard to the degree of liver damage. Inclusion criteria were: age over 21 yrs, at least 3-yrs history of alcoholic liver disease, HBV and HCV-negativity, absence of autoimmunological diseases. The presence of autoantibodies AMA-M2, SLA/LP, LKM-1, LC1, anti-F-actin, desmin and miozin in serum was assessed by immunoblotting method and ANA by ELISA. Autoantibodies were demonstrated in sera of 33% of patients. Single isolated autoantibodies were present in 24% of patients, whereas 9% of patients have several autoantibodies. The most prevalent were anti-F-actin (19%) and antinuclear antibodies (11%). Occurrence of anti-F-actin antibodies increased with degree of liver damage. Concluding these results suggest that alcohol may contribute to the activation of autoimmune processes, and particularly against contractile filaments of cells for which F-actin antibodies are produced.
Derksen, V F A M; Huizinga, T W J; van der Woude, D
Rheumatoid arthritis (RA) is an autoimmune disease characterized by joint inflammation. The presence of autoantibodies in the sera of RA patients has provided many clues to the underlying disease pathophysiology. Based on the presence of several autoantibodies like rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), anti-carbamylated protein antibodies (anti-CarP), and more recently anti-acetylated protein antibodies RA can be subdivided into seropositive and seronegative disease. The formation of these autoantibodies is associated with both genetic and environmental risk factors for RA, like specific human leukocyte antigen (HLA) alleles and smoking. Autoantibodies can be detected many years before disease onset in a subset of patients, suggesting a sequence of events in which the first autoantibodies develop in predisposed hosts, before an inflammatory response ensues leading to clinically apparent arthritis. Research on the characteristics and effector functions of these autoantibodies might provide more insight in pathophysiological processes underlying arthritis in RA. Recent data suggests that ACPA might play a role in perpetuating inflammation once it has developed. Furthermore, pathophysiological mechanisms have been discovered supporting a direct link between the presence of ACPA and both bone erosions and pain in RA patients. In conclusion, investigating the possible pathogenic potential of autoantibodies might lead to improved understanding of the underlying pathophysiological processes in rheumatoid arthritis.
Sasso, E H; Silverman, G J; Mannik, M
Staphylococcal protein A (SPA) is a bacterial membrane protein that possesses, in addition to its Fc gamma-binding activity, a distinct specificity for the Fab region of some IgM, IgA, IgG, and IgE. The Fab site that binds to SPA has been localized to the V region of the Ig H chain. In a previous study of human monoclonal and polyclonal IgM, we demonstrated that binding to SPA was highly restricted to molecules of the VHIII subgroup, and that nearly all VHIII IgM were able to bind SPA. The present study examines the VH composition of SPA-binding and SPA-nonbinding fractions of purified human polyclonal IgA, and IgG F(ab')2 fragments. We found that 22% of the IgA and 15% of the IgG F(ab')2 bound to SPA-agarose. Analysis with VH subgroup-specific antisera indicated that the SPA-binding fraction of IgA was dominated by the VHIII subgroup, and the SPA-binding fraction of IgG F(ab')2 contained only VHIII molecules. Furthermore, substantial portions of the total VHIII protein in IgA and in IgG F(ab')2 bound to SPA. We conclude that Fab binding to SPA is both restricted to and highly prevalent among human VHIII molecules, regardless of Ig class. These results suggest that protein A is an Ig superantigen.
Neuber, K; Mähnss, B; Hübner, C; Gergely, H; Weichenthal, M
The B7-1/B7-2-CD28/CTLA-4 pathway is crucial in regulating T cell activation and tolerance. Autoantibodies to surface molecules on lymphocytes have already been described in various immune conditions, such as autoimmune diseases, infections and blood transfusions. The objective of this study was to test sera from healthy individuals and from patients for association of CD28 autoantibodies with inflammatory and non-inflammatory diseases. First, CD28 was obtained by digestion of CD28-Ig fusion protein with trypsin. The cleavage products were separated by sodium dodecyl sulphate–page gel electrophoresis. Additionally, a CD28/GST fusion protein was expressed in Escherichia coli and was used to establish an enzyme-linked immunosorbent assay for detection of autoantibodies against CD28. Sera from healthy individuals (n = 72) and patients with different inflammatory and non-inflammatory skin diseases (n = 196) were tested for the presence of autoantibodies against CD28. Using mixed lymphocyte reaction (MLR), purified autoantibodies against CD28 were tested for their effects on CTLA-4-Ig-induced T cell anergy. In this study, for the first time, we describe the existence of autoantibodies against CD28 in humans which are associated with atopic diseases, e.g. allergic rhinitis and asthma. These antibodies stimulate T cells and overcome the CTLA-4-Ig-induced anergy of T cells in an MLR. The existence of autoantibodies against CD28, which may have a T cell-stimulating function, has been shown. The data indicate that autoantibodies against CD28 could be a new immunological mechanism in allergic inflammation. Additionally, autoantibodies against CD28 could be an important new marker to discriminate between atopic diseases and other inflammatory skin diseases. PMID:17034578
Barcenas-Morales, Gabriela; Jandus, Peter; Döffinger, Rainer
Concise overview of the field of anticytokine autoantibodies with a focus on recent developments. Advances in particular in the analysis of autoantibodies to IFNγ, granulocyte-macrophage colony-stimulating factor (GM-CSF) and type I IFN are presented. The target epitope for anti-IFNγ autoantibodies has been found to have high homology to a protein from Aspergillus suggesting molecular mimicry as a mechanism of breaking self-tolerance. A treatment strategy using a recombinant, epitope-depleted version of IFNγ is suggested. Autoantibodies to GM-CSF are associated with disseminated Crytococcus and Nocardia infections thus expanding the spectrum of associated diseases beyond pulmonary alveolar proteinosis. Detailed analysis of anti-GM-CSF autoantibody clones derived from pulmonary alveolar proteinosis patients show evidence of high somatic mutation suggesting T cell-dependent affinity maturation; full GM-CSF neutralization is achieved by synergistic binding of antibodies targeting various distinct noncross-reactive epitopes and leading to antigen sequestration and Fc-mediated clearance. Single mAbs in contrast may lead to higher GM-CSF bioavailability. Anti type I IFN-specific autoantibodies derived from autoimmune polyglandular syndrome type I patients are of extreme high affinity and negatively correlate with the incidence of type I diabetes and may be thus considered to be protective. Hypomorphic severe combined immune deficiency may be associated with complex anticytokine patterns and the emergence of anti type I IFN autoantibodies correlates with severe viral infection histories. Anticytokine autoantibodies may cause susceptibility to infections. In autoimmune/autoinflammatory conditions, anticytokine autoantibodies may be protective or promote disease.
Mammen, Andrew L
Dermatomyositis (DM) and polymyositis (PM) are autoimmune myopathies characterized clinically by proximal muscle weakness, muscle inflammation, extramuscular manifestations, and frequently, the presence of autoantibodies. Although there is some overlap, DM and PM are separate diseases with different pathophysiological mechanisms. Furthermore, unique clinical phenotypes are associated with each of the myositis-specific autoantibodies (MSAs) associated with these disorders. This review will focus on the clinical features, pathology, and immunogenetics of PM and DM with an emphasis on the importance of autoantibodies in defining unique phenotypes and, perhaps, as clues to help elucidate the mechanisms of disease.
Novas, A M P; Rowbottom, D G; Jenkins, D G
Tennis played at an elite level requires intensive training characterized by repeated bouts of brief intermittent high intensity exercise over relatively long periods of time (1 - 3 h or more). Competition can place additional stress on players. The purpose of this study was to investigate the temporal association between specific components of tennis training and competition, the incidence of upper respiratory tract infections (URTI), and salivary IgA, in a cohort of seventeen elite female tennis players. Timed, whole unstimulated saliva samples were collected before and after selected 1-h training sessions at 2 weekly intervals, over 12 weeks. Salivary IgA concentration was measured by ELISA and IgA secretion rate calculated (microg IgA x ml -1 x ml saliva x min -1). Players reported URTI symptoms and recorded training and competition in daily logs. Data analysis showed that higher incidence of URTI was significantly associated with increased training duration and load, and competition level, on a weekly basis. Salivary IgA secretion rate (S-IgA) dropped significantly after 1 hour of tennis play. Over the 12-week period, pre-exercise salivary IgA concentration and secretion rate were directly associated with the amount of training undertaken during the previous day and week (p < 0.05). However, the decline in S-IgA after 1 h of intense tennis play was also positively related to the duration and load of training undertaken during the previous day and week (p < 0.05). Although exercise-induced suppression of salivary IgA may be a risk factor, it could not accurately predict the occurrence of URTI in this cohort of athletes.
Takahashi, Kazuo; Wall, Stephanie B.; Suzuki, Hitoshi; Smith, Archer D.; Hall, Stacy; Poulsen, Knud; Kilian, Mogens; Mobley, James A.; Julian, Bruce A.; Mestecky, Jiri; Novak, Jan; Renfrow, Matthew B.
IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the world. Aberrantly glycosylated IgA1, with galactose (Gal)-deficient hinge region (HR) O-glycans, plays a pivotal role in the pathogenesis of the disease. It is not known whether the glycosylation defect occurs randomly or preferentially at specific sites. We have described the utility of activated ion-electron capture dissociation (AI-ECD) mass spectrometric analysis of IgA1 O-glycosylation. However, locating and characterizing the entire range of O-glycan attachment sites are analytically challenging due to the clustered serine and threonine residues in the HR of IgA1 heavy chain. To address this problem, we analyzed all glycoforms of the HR glycopeptides of a Gal-deficient IgA1 myeloma protein, mimicking the aberrant IgA1 in patients with IgAN, by use of a combination of IgA-specific proteases + trypsin and AI-ECD Fourier transform ion cyclotron resonance (FT-ICR) tandem mass spectrometry (MS/MS). The IgA-specific proteases provided a variety of IgA1 HR fragments that allowed unambiguous localization of all O-glycosylation sites in the six most abundant glycoforms, including the sites deficient in Gal. Additionally, this protocol was adapted for on-line liquid chromatography (LC)-AI-ECD MS/MS and LC-electron transfer dissociation MS/MS analysis. Our results thus represent a new clinically relevant approach that requires ECD/electron transfer dissociation-type fragmentation to define the molecular events leading to pathogenesis of a chronic kidney disease. Furthermore, this work offers generally applicable principles for the analysis of clustered sites of O-glycosylation. PMID:20823119
Characterization of the IgA and subclass IgG responses to neutralizing epitopes after infection of pregnant sows with the transmissible gastroenteritis virus or the antigenically related porcine respiratory coronavirus.
De Diego, M; Rodríguez, F; Alcaraz, C; Gómez, N; Alonso, C; Escribano, J M
In this study, we have investigated the characteristics of secreted IgA and other classes of Ig induced after vaccination of sows with transmissible gastroenteritis virus (TGEV) or the antigenically related porcine respiratory coronavirus (PRCV). Both viruses induced the secretion of neutralizing antibodies of different classes in the sows' milk, but these protected suckling piglets against TGEV to different degrees. Quantitative differences in the induction of IgA by both viruses were found among the different viral antigenic sites and subsites of glycoprotein S. In TGEV-vaccinated sows, antigenic subsite A was the best inducer of IgA, followed by antigenic site D. After vaccination with PRCV, lower levels of IgA were detected on colostrum and milk, antigenic site D and subsite Ab being the immunodominant sites. This quantitative difference in epitope recognition could explain the differences in newborn piglet protection found using Ig classes purified from the milk of sows immunized with both viruses. Apparently only IgA recognizing at least antigenic sites A and D confers good protection in vivo, whereas any Ig class recognizing only one antigenic site may neutralize the virus in cell culture. These results indicate that the formulation of a subunit vaccine against TGEV has to consider the inclusion of more than one antigenic site involved in virus neutralization.
Blaes, F; Pike, M G; Lang, B
Opsoclonus-myoclonus syndrome or Dancing Eye Syndrome (OMS/DES) is a rare neurological disorder of children, which associates with neuroblastoma (NB) in approximately 50% of cases. We examined sera from five patients with (OMS-NB(+)) and five without NB (OMS-NB(-)) for autoantibodies. OMS-NB(-) IgG bound to the surface of a NB cell line, whereas IgG from OMS-NB(+) and from NB patients without OMS/DES bound only to permeabilised cells. Both OMS-NB(+) and OMS-NB(-) reduced proliferation of NB cells. We also present a case report of a child with OMS/DES without NB who made a complete recovery without treatment. Serum antibodies at presentation bound to the surface and decreased NB cell proliferation but had decreased 9 weeks later when the child was asymptomatic. These results demonstrate that sera from some OMS/DES patients contain IgG antibodies that are potentially pathogenic.
Testing for IgG class antibodies in celiac disease patients with selective IgA deficiency. A comparison of the diagnostic accuracy of 9 IgG anti-tissue transglutaminase, 1 IgG anti-gliadin and 1 IgG anti-deaminated gliadin peptide antibody assays.
Villalta, Danilo; Alessio, Maria Grazia; Tampoia, Marilina; Tonutti, Elio; Brusca, Ignazio; Bagnasco, Marcello; Pesce, Giampaola; Stella, Sergio; Bizzaro, Nicola
To evaluate the diagnostic characteristics of commercially available IgG anti-tTG assays in selective IgA deficiency (SIgAD), we tested different IgG anti-tTG methods and compared the results with those obtained from two other tests: one for IgG anti-gliadin (AGA) and one for IgG to deaminated gliadin peptides (DGP). 20 CD patients with SIgAD and 113 controls (9 patients with SIgAD without CD; 54 patients with chronic liver disease; 50 healthy subjects) were tested with 9 IgG anti-tTG assays (2 of which are enriched with gliadin peptides), one IgG AGA assay and one IgG anti-DGP assay. Using optimal cutoffs as determined by ROC curves, the sensitivity of IgG anti-tTG methods ranged from 75% (1 kit) to 95% (7 kits) and the specificity from 94% (1 kit) to 100% (5 kits). Sensitivity and specificity were 40% and 87% for IgG AGA, and 80% and 98% for IgG anti-DGP, respectively. All IgG anti-tTG methods evaluated are reliable serologic assays for the diagnosis of CD in patients with SIgAD and perform better than the gliadin-based assays used in this study. The tests containing both tTG and gliadinic peptides are burdened by a lower specificity than the anti-tTG assays.
Saurat, J.H.; Schifferli, J.; Steiger, G.; Dayer, J.M.; Didierjean, L. )
Since autoantibodies (Abs) to cytokines may modify their biologic activities, high-affinity binding factors for interleukin-1 alpha (IL-1 alpha BF) were characterized in human sera. IL-1 alpha BF was identified as IgG (1) by sucrose density-gradient centrifugation followed by immunodiffusion autoradiography, (2) by ligand-blotting method, (3) by ligand binding to affinity-immobilized serum IgG, and (4) by IgG affinity purification followed by sucrose density-gradient centrifugation. IL-1 alpha binding activity resided in the F(ab)2 fragment. The apparent equilibrium constant was in the range of IgG found after immunization with conventional antigens (i.e., 10(-9) to 10(-10) mol/L). Anti-IL-1 alpha IgG auto-Abs represented only an extremely small fraction of total IgG (less than 1/10(-5)). Some sera with IL-1 alpha BF and purified IgG thereof were able to inhibit by 96% to 98% the binding of human recombinant IL-1 alpha to its receptor on murine thymoma EL4-6.1 cells, whereas other sera did not. When 125I-labeled anti-IL-1 alpha IgG complexes were injected into rats, they prolonged the plasma half-life of 125I-labeled IL-1 alpha several fold and altered its tissue distribution. The predominant class was IgG (12/19), mainly IgG4 (9/19), but in five of the sera, anti-IL-1 alpha IgA was also detected. In a screening of 271 sera, IL-1 alpha BF was detected in 17/98 normal subjects and was not more frequent in several control groups of patients, except in patients with Schnitzler's syndrome (fever, chronic urticaria, bone pain, and monoclonal IgM paraprotein) (6/9; p less than 0.005). The pathologic significance of these auto-Abs remains to be determined.
Kivity, Shaye; Gilburd, Boris; Agmon-Levin, Nancy; Carrasco, Marina Garcia; Tzafrir, Yaron; Sofer, Yael; Mandel, Matilda; Buttner, Thomas; Roggenbuck, Dirk; Matucci-Cerinic, Marco; Danko, Katalin; Hoyos, Marcos López; Shoenfeld, Yehuda
Autoantibodies (AAb), especially antinuclear (ANAs) and anticytoplasmatic antibodies (ACyA), are essential diagnosing markers for several autoimmune diseases. The current gold standard method for ANA detection is manual indirect immunofluorescence (IIF) on human epithelial-2 (HEp-2) cells. However, this technique is cost and time consuming, and characterized by considerable intra- and interlaboratory variability. Thus, an automated IIF-HEp-2 reader has been developed recently. In the current study, we compared the performance of the automated AAb IIF-HEp-2 interpretation to conventional detection methods. Autoantibody detection by IIF on HEp-2 cells was performed in a total of 260 sera of patients, including 34 with systemic lupus erythematosus, 111 with dermatomyositis or polymyositis, 74 with systemic sclerosis, 41 with rare AAb patterns, and 137 healthy individuals. Visual interpretation and routine immunoassays were compared with a novel automated IIF-HEp-2 system using Aklides pattern recognition algorithms. Positive AAbs were detected in 95-100% of rheumatic patients by automated interpretation, in 74-100% with manual reading, and in 64-100% by immunodot assay. Receiver operating characteristic curve analysis of fluorescent intensity revealed a high sensitivity and specificity for automated reading of AAb with an agreement ranging from 90% to 95% between manual and automated interpretation (kappa 0.554-0.69) for systemic sclerosis and myositis, respectively. This study demonstrates a good correlation between manual and automated interpretation of AAb including ANA and ACyA in patients with autoimmune diseases. Full automation of HEp-2 cell assay reading may minimize errors in ANA pattern interpretation and thus help in the standardization of ANA assessment.
Rivera, V; Hernández, D; Rojas, S; Oliver, G; Serrano, J; Shibayama, M; Tsutsumi, V; Campos, R
Antibodies from IgA and IgM classes that recognize Naegleria fowleri (Nf) proteins were detected by the ELISA assay in serum and saliva from three groups of people: (i) subjects with upper respiratory tract infections (URTI) living in the parasite-endemic area, (ii) healthy persons from the same area, and (iii) healthy persons from a parasite-nonendemic area. In serum and in saliva the titers of IgA antibodies to Naegleria fowleri in the group of patients with URTI was significantly higher than that of the healthy group in the parasite-endemic area; also the titers of IgM antibodies in serum were significantly higher in patients. On the contrary, in saliva the antibodies were higher in healthy people from the parasite-endemic area. In all cases the subjects from the parasite-nonendemic area had lower antibody titers in serum and saliva.
Delbarba, Elisa; Pedroni, Bruno; Dallera, Nadia; Izzi, Claudia; Scolari, Francesco
IgA nephropathy is the most common form of primary glomerulonephritis, with a variable prevalence depending on the geographic area of examination. Marked differences in disease prevalence has suggested that genetics could play a role in the pathogenesis of the disease, indicating the existence of susceptibility genes detected with different frequencies in geographically separated populations. Moreover, familial forms of IgAN have been reported worldwide, in sibling pairs, families and extended pedigrees belonging to geographically isolated populations. In this article we describe recent discoveries in genetic studies on IgAN. If candidate-gene association studies require first survey on the pathogenesis of the disease, since the candidate loci are selected on the basis of information gathered from traditional biology, the linkage analysis consist in an alternative approach. Several susceptibility loci have been identified in pedigrees segregating for IgAN, but not the causative mutations of the disease. Further progress in the field of knowledge about the genetics of IgAN has recently been obtained by the application of genome-wide association studies (GWAS) in large cohorts of cases and controls of IgAN. GWAS have identified multiple susceptibility loci coding for genes involved in critical mechanisms for the development of IgAN and, accordingly, have shed new light on the biology of the disease, revealing unknown pathogenic pathways. The close connection between IgAN and many autoimmune diseases has been demonstrated. Moreover, these studies have made the correlation of genetic risk score of developing IgAN with the geo-epidemiological aspect of the disease possible. The goal of the integrated genomic approach will be to discover new potential therapeutic targets.
Kunisawa, Jun; Gohda, Masashi; Hashimoto, Eri; Ishikawa, Izumi; Higuchi, Morio; Suzuki, Yuji; Goto, Yoshiyuki; Panea, Casandra; Ivanov, Ivaylo I.; Sumiya, Risa; Aayam, Lamichhane; Wake, Taichi; Tajiri, So; Kurashima, Yosuke; Shikata, Shiori; Akira, Shizuo; Takeda, Kiyoshi; Kiyono, Hiroshi
Intestinal plasma cells predominantly produce immunoglobulin (Ig) A, however, their functional diversity remains poorly characterized. Here we show that murine intestinal IgA plasma cells can be newly classified into two populations on the basis of CD11b expression, which cannot be discriminated by currently known criteria such as general plasma cell markers, B cell origin and T cell dependence. CD11b+ IgA+ plasma cells require the lymphoid structure of Peyer’s patches, produce more IgA than CD11b− IgA+ plasma cells, proliferate vigorously, and require microbial stimulation and IL-10 for their development and maintenance. These features allow CD11b+ IgA+ plasma cells to mediate early-phase antigen-specific intestinal IgA responses induced by oral immunization with protein antigen. These findings reveal the functional diversity of IgA+ plasma cells in the murine intestine. PMID:23612313
Patwa, Tasneem H.; Wang, Yanfei; Simeone, Diane M.; Lubman, David M.
High-throughput studies to determine differential immune (humoral) response to diseases are becoming of increasing interest because the information they provide can help in early diagnosis as well as monitoring of therapeutics. Protein microarrays are a high-throughput and convenient technology that can be applied to the study of the humoral response. Proteins can be arrayed on slides and then probed with serum from different classes of patients to observe differences that may exist among autoantibodies that reflect differences in disease states. However, such studies may be difficult to interpret due to the weak overall signal response of such protein microarrays. We propose that this weak signal response is due to the physical positioning of the disease proteins that renders them sterically hindered from binding partners in the serum. In this study, we hypothesize that reducing the complexity and size of the disease proteins by chemical digestion using cyanogen bromide (CNBr) may enhance the overall signal from the humoral response and facilitate visualization of disease-specific responses in various classes of serum. A modified protein microarray methodology using CNBr digestion is presented here. The new workflow was applied to a set of 10 serum samples from healthy subjects, 10 from patients with chronic pancreatitis and 10 from patients diagnosed with pancreatic cancer and the results were compared to results obtained in the absence of CNBr digestion. CNBr digestion allowed the identification of 10 additional autoantibodies that responded to serum, 5 of which were unique to pancreatitis and cancer sera. This new methodology may increase the sensitivity of microarray studies measuring autoantibodies in serum. PMID:18452326
Kemp, M; Husby, S; Larsen, M L; Svehag, S E
Enzyme immunoassays for the quantitation of IgA1 and IgA2 antibodies to dietary antigens were developed. Serum IgA1 antibodies to bovine serum albumin (BSA) were detectable in 2/30 healthy adults, in 3/26 healthy children, and at high levels in 8/11 children with coeliac disease, without relation to gluten exposure. IgA1 antibodies to ovalbumin (OA) and beta-lactoglobulin (BLG) at high titers were seen in one coeliac child but were otherwise low or absent. IgA2 antibodies to BSA were detectable in 28/48 healthy subjects and in 8/11 coeliac children. IgA2 antibodies to OA and BLG were measurable in a few samples from each group. IgA1 antibodies to the gluten component glycgli were found at low levels in 15/56 normal sera, and anti-glycgli antibodies of the IgA2 subclass in 14/48 sera from healthy persons, also at low levels. IgA1 anti-glycgli antibodies were measurable in 5/11 sera from CD patients on a gluten-free diet. Elevated levels of IgA1 anti-glycgli antibodies were detected in all sera from CD patients challenged with gluten, except in 1 patient with a markedly reduced serum IgA level. In contrast, the IgA2 anti-glycgli antibody levels were unaffected. Thus, increased levels of IgA antibodies to dietary protein antigens in childhood coeliac disease were observed only within the IgA1 isotype.
Zhang, Cong; Ye, Leiguang; Guan, Songlei; Jin, Shunzi; Wang, Weili; Sun, Shilong; Lee, Kuang-Hui; Wei, Jun; Liu, Baogang
Overexpression of tumor-associated antigens (TAAs) has been reported in many types of cancer and may trigger secretion of their autoantibodies. The present work was thus designed to test whether circulating antibody to p16 protein-derived antigens was altered in lung cancer. Two hundred seventy-one patients with non-small cell lung cancer (NSCLC) and 226 control subjects matched in age, gender, and smoking history were recruited in this study. The levels of circulating anti-p16 IgA and IgG antibodies were tested using an enzyme-linked immunosorbent assay (ELISA) developed in-house with linear peptide antigens derived from p16 protein. Student’s t test showed that patients with NSCLC had a significant higher level of anti-p16 IgG antibody than control subjects (t = 2.74, P = 0.0063) but did not have a significant increase in IgA antibody levels (t = 1.92, P = 0.056). The sensitivity against >90% specificity was 19.7% for the IgG assay with an inter-assay deviation of 11.6%, and 10.3% for the IgA assay with an inter-assay deviation of 14.7%. Based on a cut-off value determined by the 99th percentile of control IgG levels, the anti-p16 IgG positivity was 6.7% in patients with NSCLC compared to 0.88% in control subjects (χ (2) = 10.58, P = 0.001, OR = 7.97, 95% CI 1.84–34.85). Circulating anti-p16 IgG levels were increased with stages of NSCLC, and patients with stage IV NSCLC had the highest IgG level among all four stages (t = 2.42, P = 0.016, compared with the control group). Pearson correlation analysis showed a significant correlation between circulating levels of IgA and IgG in the patient group (r = −0.2, df = 236, P = 0.0021) but not in the control group (r = −0.1, df = 205, P = 0.146). Circulating IgG antibody to p16 protein may be a potential biomarker with prognostic values for lung cancer.
Konstantinov, K; von Mikecz, A; Buchwald, D; Jones, J; Gerace, L; Tan, E M
We have identified and partially characterized the autoantibodies in sera of 60 patients with chronic fatigue syndrome. Approximately 52% of the sera were found to react with nuclear envelope antigens. The combination of nuclear rim staining observed in immunofluorescence microscopy and immunoblot analysis of highly purified nuclear envelope proteins provided initial characterization of these autoantibodies. Further characterization showed that some sera immunoprecipitated the in vitro transcription and translation product of a human cDNA clone encoding the nuclear envelope protein lamin B1. The autoantibodies were of the IgG isotype. The occurrence of autoantibodies to a conserved intracellular protein like lamin B1 provides new laboratory evidence for an autoimmune component in chronic fatigue syndrome. PMID:8878441
Riemekasten, Gabriela; Philippe, Aurélie; Näther, Melanie; Slowinski, Torsten; Müller, Dominik N; Heidecke, Harald; Matucci-Cerinic, Marco; Czirják, László; Lukitsch, Ivo; Becker, Mike; Kill, Angela; van Laar, Jacob M; Catar, Rusan; Luft, Friedrich C; Burmester, Gerd R; Hegner, Björn; Dragun, Duska
Systemic sclerosis (SSc) features autoimmunity, vasculopathy and tissue fibrosis. The renin-angiotensin and endothelin systems have been implicated in vasculopathy and fibrosis. A role for autoantibody-mediated receptor stimulation is hypothesised, linking three major pathophysiological features consistent with SSc. Serum samples from 478 patients with SSc (298 in the study cohort and 180 from two further independent cohorts), 372 healthy subjects and 311 control-disease subjects were tested for antibodies against angiotensin II type 1 receptor (AT(1)R) and endothelin-1 type A receptor (ET(A)R) by solid phase assay. Binding specificities were tested by immunoprecipitation. The biological effects of autoantibodies in microvascular endothelial cells in vitro were also determined, as well as the quantitative differences in autoantibody levels on specific organ involvements and their predictive value for SSc-related mortality. Anti-AT(1)R and anti-ET(A)R autoantibodies were detected in most patients with SSc. Autoantibodies specifically bound to respective receptors on endothelial cells. Higher levels of both autoantibodies were associated with more severe disease manifestations and predicted SSc-related mortality. Both autoantibodies exert biological effects as they induced extracellular signal-regulated kinase 1/2 phosphorylation and increased transforming growth factor β gene expression in endothelial cells which could be blocked with specific receptor antagonists. Functional autoimmunity directed at AT(1)R and ET(A)R is common in patients with SSc. AT(1)R and ET(A)R autoantibodies could contribute to disease pathogenesis and may serve as biomarkers for risk assessment of disease progression.
Martins, La Salete; Henriques, Antonio C; Fonseca, Isabel M; Rodrigues, Anabela S; Oliverira, José C; Dores, Jorge M; Dias, Leonidio S; Cabrita, Antonio M; Silva, José D; Noronha, Irene L
Type 1 diabetes recurrence has been documented in simultaneous pancreas-kidney transplants (SPKT), but this diagnosis may be underestimated. Antibody monitoring is the most simple, noninvasive, screening test for pancreas autoimmune activity. However, the impact of the positive autoimmune markers on pancreas graft function remains controversial. In our cohort of 105 SPKT, we studied the cases with positive pancreatic autoantibodies. They were immunosuppressed with antithymocyte globulin, tacrolimus, mycophenolate, and steroids. The persistence or reappearance of these autoantibodies after SPKT and factors associated with their evolution and with graft outcome were analyzed. Pancreatic autoantibodies were prospectively monitored. Serum samples were collected before transplantation and at least once per year thereafter. At the end of the follow-up (maximum 138 months), 43.8% of patients were positive (from pre-transplant or after recurrence) for at least one autoantibody - the positive group. Antiglutamic acid decarboxylase was the most prevalent (31.4%), followed by anti-insulin (8.6%) and anti-islet cell autoantibodies (3.8%). Bivariate analysis showed that the positive group had higher fasting glucose, higher glycated hemoglobin (HbA1c), lower C-peptide levels, and a higher number of HLA-matches. Analyzing the sample divided into four groups according to pre-/post-transplant autoantibodies profile, the negative/positive group tended to present the higher HbA1c values. Multivariate analysis confirmed the significant association between pancreas autoimmunity and HbA1c and C-peptide levels. Positivity for these autoantibodies pre-transplantation did not influence pancreas survival. The unfavorable glycemic profile observed in the autoantibody-positive SPKT is a matter of concern, which deserves further attention. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Cugno, Massimo; Gualtierotti, Roberta; Tedeschi, Alberto; Meroni, Pier Luigi
Autoantibodies may develop against coagulation factors altering their function or promoting their rapid clearance. In non-congenitally deficient patients, they are usually in association with autoimmune diseases, malignancies, pregnancy or advanced age. The possible development of coagulation factor autoantibodies should be considered when a patient presents with bleeding symptoms without any prior bleeding diathesis. The most common disorder associated with coagulation factor autoantibodies is acquired factor VIII deficiency, which is characterized by hemorrhages involving soft tissues, muscles and skin; hemarthroses are less frequent than in the inherited form. Acquired deficiencies of von Willebrand factor and factor XIII due to autoantibodies are emerging conditions. Autoantibodies to the other coagulation factors may be associated with a wide spectrum of clinical manifestations ranging from minimal or no bleeding to life-threatening conditions. The diagnostic approach begins with global coagulation tests: prothrombin time (PT) and activated partial thromboplastin time (aPTT). In case of prolonged times, mixing studies (typically using normal plasma in a 1:1 proportion) should be performed. Specific factor and inhibitor assays, assessment of lupus anticoagulant and eventually enzyme immunoassays for specific anti-factor antibodies complete the evaluation. A prompt diagnosis of specific coagulation factor inhibitors is mandatory for starting an appropriate treatment aimed at overcoming the deficient factor, in case of bleeding, and, if possible, at the suppression of the autoantibody's production. © 2013 Elsevier B.V. All rights reserved.
Jackson, Michael W; Reed, Joanne H; Smith, Anthony J F; Gordon, Tom P
Despite strong circumstantial evidence for the autoimmune hypothesis of narcolepsy, conventional immunological methods have failed to detect an autoantibody. This study investigated the real-time effects of narcoleptic immunoglobulins on a spontaneous colonic migrating motor complex (CMMC) preparation. IgG from patients with narcolepsy with cataplexy or healthy controls was added directly to isolated mouse colons undergoing CMMC activity to test for autoantibodies that disrupt colonic motility. The effect of immunoglobulins prepared for clinical intravenous treatment (IVIg) on autoantibody-mediated colonic disruption was also assessed. Narcoleptic IgGs markedly reduced the frequency of CMMCs or irreversibly abolished them. Abrogation of CMMCs was followed by an increase in the resting tension of the colon preparation and appearance of atropine-sensitive phasic smooth muscle contractions. IVIg partially neutralized the inhibitory effect of narcoleptic IgG on the CMMCs. The dramatic effect of narcoleptic IgG on CMMC generation is consistent with an autoantibody-mediated disruption of enteric neural pathways. The ex vivo whole-organ approach allows real-time examination of the physiological effects of the narcoleptic autoantibody and offers a new avenue for exploring the autoimmune basis of narcolepsy. The neutralizing effect of IVIg on the autoantibody provides a rationale for the reported clinical improvement in cataplexy when IVIg are given at disease onset.
Reyes-Baraona, Francisco; Andino, Romina; Carrasco, Juan Eduardo; Arriagada, Camila; Guerrero, Silvia
Linear IgA bullous dermatosis is a rare acquired autoinmune vesiculobullous disease characterized by linear IgA deposit on the dermo-epidermal basement membrane observed with direct inmunofluorescence. The characteristic lesions are vesicles and tense serous bullae, which most often are grouped giving a "cluster of jewels" appearance. Differential diagnosis must be established with other autoimmune dermatosis, such as dermatitis herpetiformis and bullous pemphigoid. Dapsone is the first line therapy, with excellent response in a short period. This is a benign disease that tends to wax and wane in severity until it disappears spontaneously. We report the case of a 5-year-old girl presenting with bullous lesions, being diagnosed a linear IgA bullous dermatosis, with excellent response to dapsone in less than 2 weeks.
Velásquez-Jones, L; Sánchez-Aguilar, J R; Ramòn-Garcia, G; Rosado-Tun, M A; Romero-Navarro, B; Gómez-Chico, R; Muñoz-Arizpe, R
IgA nephropathy, also called Berger's disease, is characterized by recurrent gross hematuria or persistent microscopic hematuria, together with mesangial glomerular deposits of IgA found in the renal biopsy. Seven children with IgA nephropathy were studied. Most of them presented initially with recurrent macroscopic hematuria and low or moderate-grade proteinuria, without hypertension or renal function impairment. Only one patient presented with a rapidly progressive glomerulonephritis. Four patients did not receive any treatment; one of them is in remission, one has improved and two remain with moderate proteinuria and hematuria. One patient with significant proteinuria improved after prednisone and azathioprine treatment. The patient with rapidly progressive glomerulonephritis improved his renal function after oral prednisone and intravenous boluses of methylprednisolone and cyclophosphamide.
Russu, R; Popescu, C
In a group of 84 patients with recidivating bronchial infections IgA were evaluated with the aid of radial immunodiffusion according to Mancini. In all the patients IgA were determined from expectoration extractions and in 50 of them serum IgA were also determined. In 38 cases the determinations were simultaneous. Concentration of S IgA was low in most of the cases (65%). These results are probably influenced by the technical difficulties raised by detaching the connections existing between S IgA and mucus fibrils from the bronchial secretion. The results obtained in the dosage of serum IgA are comparable with those mentioned in the current literature. No correlations were possible between S IgA and serum IgA and there proteins can be considered as independent.
Fabien, Nicole; Goetz, Joëlle; Sordet, Christelle; Humbel, René-Louis; Sibilia, Jean
New treatment strategies require that rheumatoid arthritis (RA) be diagnosed as early as possible. New diagnostic markers were required, because rheumatoid factors (RF), until now criteria for classification of RA, are not sufficiently specific and sometimes appear late, thereby limiting their diagnostic usefulness. The objective of this review is to describe the current state of knowledge and more particularly to analyze the interest of new RA autoanti-bodies, called anti-peptide or anti-citrullinated protein anti-bodies (ACPA). Other autoanti-bodies have been described, including anti-Sa, anti-alpha enolase, and anti-calpastatin autoanti-bodies. Nonetheless, their diagnostic value remains limited compared to ACPA. Accordingly, in daily practice today, the only autoanti-bodies that must be tested for to diagnose RA are the ACPAs and RFs. The discovery of ACPA (initially called anti-keratin and anti-perinuclear anti-bodies) was a major step forward for the laboratory diagnosis of RA. The tests most often used routinely areenzyme-linked immunosorbent assays(ELISA) with cyclic citrullinated peptides, whence the name anti-CCP autoanti-bodies. Accordingly, the two terms ACPA and anti-CCP can both be used. The diagnostic value, in particular their specificity, is on the order of 95%, regardless of the method of identification. These markers are very useful and are often present earlier than RF. These ACPA also have prognostic value because they are associated with more aggressive forms of RA. On the other hand, their value over time, in particular, their fluctuation as a function of treatment, is more controversial. In practice, it is recommended to test for both RF and ACPA in a diagnostic work-up for early RA. During follow-up, the value of testing for these autoanti-bodies has not been demonstrated, but additional studies are still necessary with the anti-CCP autoanti-bodies and the new anti-citrullinated protein autoanti-bodies.
Norris, Ivy N; Haeberle, M Tye; Callen, Jeffrey P; Malone, Janine C
Linear IgA bullous dermatosis (LABD) is a sub-epidermal blistering disorder characterized by deposition of IgA along the basement membrane zone (BMZ) as detected by immunofluorescence microscopy. The diagnosis is made by clinicopathologic correlation with immunofluorescence confirmation. Differentiation from other bullous dermatoses is important because therapeutic measures differ. Prompt initiation of the appropriate therapies can have a major impact on outcomes. We present three cases with prominent palmar involvement to alert the clinician of this potential physical exam finding and to consider LABD in the right context.
Pierchalla, A; Bruch-Gerharz, D; Homey, B; Reifenberger, J
Linear IgA bullous dermatosis is an acquired autoimmune subepidermal blistering disease, characterized by linear IgA deposits at the basement membrane zone. Described in both children and adults, it occurs as tense pruritic vesicles and bullae in a "cluster of jewels" configuration with central crusting on an inflammatory elevated base. It is typically located on the face, anogenital region and trunk. Whilst the adult manifestations can be chronic, in children a spontaneous remission has often been reported. Our patient showed a spontaneous remission after 8 weeks of symptomatic topic treatment with methylprednisolone and oral cetirizine dihydrochloride.
Kiryluk, Krzysztof; Novak, Jan
IgA nephropathy (IgAN) represents the leading cause of kidney failure among East Asian populations and the most frequent form of primary glomerulonephritis among Europeans. Patients with IgAN develop characteristic IgA1-containing immune complexes that deposit in the glomerular mesangium, producing progressive kidney injury. Recent studies define IgAN as an autoimmune trait of complex architecture with a strong genetic determination. This Review summarizes new insights into the role of the O-glycosylation pathway, anti-glycan immune response, mucosal immunity, antigen processing and presentation, and the alternative complement pathway in the pathogenesis of IgAN. PMID:24892706
Andión-Fernández, M; Dorado-Fernández, T; Juárez-Casado, M A; Santamarina-Pernas, R
A 41-year-old woman with a bilateral loss of visual acuity and a history of IgA nephropathy. The ophthalmic examination revealed bilateral neurosensory detachments that resolved completely after four months of peritoneal dialysis. Bilateral serous retinal detachments are a rare manifestation of IgA nephropathy, in which the etiology is probably multifactorial and their resolution depends on the underlying disease. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.
Tissandié, Emilie; Morelle, Willy; Berthelot, Laureline; Vrtovsnik, François; Daugas, Eric; Walker, Francine; Lebrec, Didier; Trawalé, Jean-Marie; Francoz, Claire; Durand, François; Moura, Ivan C; Paradis, Valérie; Moreau, Richard; Monteiro, Renato C
Abnormalities of IgA arise in alcoholic cirrhosis, including mesangial IgA deposits with possible development of secondary IgA nephropathy (IgAN). Since little is known about circulating immune complexes in cases of secondary IgAN, we analyzed IgA-associated parameters in the serum of 32 patients with compensated or advanced alcoholic cirrhosis. Galactose deficiency and decreased sialylation of IgA1, as well as increased amounts of abnormally glycosylated polymeric IgA1, were detected in the serum of patients with advanced alcoholic cirrhosis. Moreover, aberrant IgA1 formed complexes with IgG and soluble CD89 in serum of patients with advanced alcoholic cirrhosis, similar to those found in primary IgAN. The IgA1 of alcoholic cirrhosis, however, had a modified N-glycosylation, not found in primary IgAN. In patients with alcoholic cirrhosis and IgAN, IgA deposits were associated with CD71 overexpression in mesangial areas, suggesting that CD71 might be involved in deposit formation. Although the IgA1 found in alcoholic cirrhosis bound more extensively to human mesangial cells than control IgA1, they differ from primary IgAN by not inducing mesangial cell proliferation. Thus, abnormally glycosylated IgA1 and soluble CD89-IgA and IgA-IgG complexes, features of primary IgAN, are also present in alcoholic cirrhosis. Hence, common mechanisms appear to be shared by diseases of distinct origins, indicating that common environmental factors may influence the development of IgAN.
Schlick, Bettina; Massoner, Petra; Lueking, Angelika; Charoentong, Pornpimol; Blattner, Mirjam; Schaefer, Georg; Marquart, Klaus; Theek, Carmen; Amersdorfer, Peter; Zielinski, Dirk; Kirchner, Matthias; Trajanoski, Zlatko; Rubin, Mark A.; Müllner, Stefan; Schulz-Knappe, Peter; Klocker, Helmut
Background Chronic inflammation is frequently observed on histological analysis of malignant and non-malignant prostate specimens. It is a suspected supporting factor for prostate diseases and their progression and a main cause of false positive PSA tests in cancer screening. We hypothesized that inflammation induces autoantibodies, which may be useful biomarkers. We aimed to identify and validate prostate inflammation associated serum autoantibodies in prostate cancer patients and evaluate the expression of corresponding autoantigens. Methods Radical prostatectomy specimens of prostate cancer patients (N = 70) were classified into high and low inflammation groups according to the amount of tissue infiltrating lymphocytes. The corresponding pre-surgery blood serum samples were scrutinized for autoantibodies using a low-density protein array. Selected autoantigens were identified in prostate tissue and their expression pattern analyzed by immunohistochemistry and qPCR. The identified autoantibody profile was cross-checked in an independent sample set (N = 63) using the Luminex-bead protein array technology. Results Protein array screening identified 165 autoantibodies differentially abundant in the serum of high compared to low inflammation patients. The expression pattern of three corresponding antigens were established in benign and cancer tissue by immunohistochemistry and qPCR: SPAST (Spastin), STX18 (Syntaxin 18) and SPOP (speckle-type POZ protein). Of these, SPAST was significantly increased in prostate tissue with high inflammation. All three autoantigens were differentially expressed in primary and/or castration resistant prostate tumors when analyzed in an inflammation-independent tissue microarray. Cross-validation of the inflammation autoantibody profile on an independent sample set using a Luminex-bead protein array, retrieved 51 of the significantly discriminating autoantibodies. Three autoantibodies were significantly upregulated in both screens, MUT
Martínez-Flores, José A; Serrano, Manuel; Pérez, Dolores; Cámara A, Gómez de la; Lora, David; Morillas, Luis; Ayala, Rosa; Paz-Artal, Estela; Morales, José M; Serrano, Antonio
Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis and/or gestational morbidity in patients with antiphospholipid autoantibodies (aPL). Over recent years, IgA anti-beta2-glycoprotein I (B2GPI) antibodies (IgA aB2GPI) have reached similar clinical relevance as IgG or IgM isotypes. We recently described the presence of immune complexes of IgA bounded to B2GPI (B2A-CIC) in the blood of patients with antecedents of APS symptomalology. However, B2A-CIC's clinical associations with thrombotic events (TEV) have not been described yet. A total of 145 individuals who were isolate positive for IgA aB2GPI were studied: 50 controls without any APS antecedent, 22 patients with recent TEV (Group-1), and 73 patients with antecedents of old TEV (Group-2). Mean B2A-CIC levels and prevalence in Group-1 were 29.6±4.1 AU and 81.8%, respectively, and were significantly higher than those of Group-2 and controls (p＜0.001). In a multivariable analysis, positivity of B2A-CIC was an independent variable for acute thrombosis with a 22.7 odd ratio (confidence interval 5.1-101.6, 95%, p＜0.001). Levels of B2A-CIC dropped significantly two months after the TEV. B2A-CIC positive patients had lower platelet levels than B2A-CIC-negative patients (p＜0.001) and more prevalence of thrombocytopenia (p＜0.019). Group-1 had no significant differences in C3 and C4 levels compared with other groups. B2A-CIC is strongly associated with acute TEV. Patients who did not develop thrombosis and were B2A-CIC positive had lower platelet levels, which suggest a hypercoagulable state. This mechanism is unrelated to complement-fixing aPL. B2A-CIC could potentially select IgA aB2GPI-positive patients at risk of developing a thrombotic event.
Martínez-Flores, José A.; Serrano, Manuel; Pérez, Dolores; de la Cámara A, Gómez; Lora, David; Morillas, Luis; Ayala, Rosa; Paz-Artal, Estela; Morales, José M.
Aim: Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis and/or gestational morbidity in patients with antiphospholipid autoantibodies (aPL). Over recent years, IgA anti-beta2-glycoprotein I (B2GPI) antibodies (IgA aB2GPI) have reached similar clinical relevance as IgG or IgM isotypes. We recently described the presence of immune complexes of IgA bounded to B2GPI (B2A-CIC) in the blood of patients with antecedents of APS symptomalology. However, B2A-CIC's clinical associations with thrombotic events (TEV) have not been described yet. Methods: A total of 145 individuals who were isolate positive for IgA aB2GPI were studied: 50 controls without any APS antecedent, 22 patients with recent TEV (Group-1), and 73 patients with antecedents of old TEV (Group-2). Results: Mean B2A-CIC levels and prevalence in Group-1 were 29.6 ± 4.1 AU and 81.8%, respectively, and were significantly higher than those of Group-2 and controls (p < 0.001). In a multivariable analysis, positivity of B2A-CIC was an independent variable for acute thrombosis with a 22.7 odd ratio (confidence interval 5.1 –101.6, 95%, p < 0.001). Levels of B2A-CIC dropped significantly two months after the TEV. B2A-CIC positive patients had lower platelet levels than B2A-CIC-negative patients (p < 0.001) and more prevalence of thrombocytopenia (p < 0.019). Group-1 had no significant differences in C3 and C4 levels compared with other groups. Conclusion: B2A-CIC is strongly associated with acute TEV. Patients who did not develop thrombosis and were B2A-CIC positive had lower platelet levels, which suggest a hypercoagulable state. This mechanism is unrelated to complement-fixing aPL. B2A-CIC could potentially select IgA aB2GPI-positive patients at risk of developing a thrombotic event. PMID:27063992
Misfolded proteins localized in the endoplasmic reticulum are degraded promptly and thus are not transported outside cells. However, misfolded proteins in the endoplasmic reticulum are rescued from protein degradation upon association with major histocompatibility complex (MHC) class II molecules and are transported to the cell surface by MHC class II molecules without being processed to peptides. Studies on the misfolded proteins rescued by MHC class II molecules have revealed that misfolded proteins associated with MHC class II molecules are specific targets for autoantibodies produced in autoimmune diseases. Furthermore, a strong correlation has been observed between autoantibody binding to misfolded proteins associated with MHC class II molecules and the autoimmune disease susceptibility conferred by each MHC class II allele. These new insights into MHC class II molecules suggest that misfolded proteins rescued from protein degradation by MHC class II molecules are recognized as "neo-self" antigens by immune system and are involved in autoimmune diseases as autoantibody targets.
Cappellano, Giuseppe; Orilieri, Elisabetta; Woldetsadik, Abiy D; Boggio, Elena; Soluri, Maria F; Comi, Cristoforo; Sblattero, Daniele; Chiocchetti, Annalisa; Dianzani, Umberto
An overview of the current literature is showing that autoantibodies (AutoAbs) against cytokines are produced in several pathological conditions, including autoimmune diseases, but can also be detected in healthy individuals. In autoimmune diseases, these AutoAbs may also be prognostic markers, either negative (such as AutoAbs to IL-8 and IL-1α in rheumatoid arthritis) or positive (such as AutoAbs to IL-6 in systemic sclerosis and those to osteopontin in rheumatoid arthritis). They may have neutralizing activity and influence the course of the physiological and pathological immune responses. High levels of AutoAbs against cytokines may even lead to immunodeficiency, such as those to IL-17 in autoimmune polyendocrine syndrome type I or those to IFN-γ in mycobacterial infections. Their role in human therapy may be exploited not only through passive immunization but also through vaccination, which may improve the costs for long lasting treatments of autoimmune diseases. Detection and quantification of these AutoAbs can be profoundly influenced by the technique used and standardization of these methods is needed to increase the value of their analysis. PMID:23885320
Berlin, Tatiana; Zandman-Goddard, Gisele; Blank, Miri; Matthias, Torsten; Pfeiffer, Sascha; Weis, Ingrid; Toubi, Elias; Singh, Sham; Asherson, Ronald; Fraser, Abigail; Gilburd, Boris; Sapir, Tal; Levy, Yair; Lukac, Janja; Rozman, Blaz; Kveder, Tanja; Shoenfeld, Yehuda
Infections can act as environmental triggers inducing or promoting autoimmune disease in genetically predisposed individuals. Identification of microbial peptides similar to self-tissues may by molecular mimicry, provide the inducing mechanism for an immune response. The aim of this study was to identify autoantibodies (autoAbs) in nonautoimmune individuals during acute bacterial, viral, or parasitic infections. Specific Abs or specific infections with an increased autoAb load may shed insight into the mechanisms of autoimmune disease. Sera from 88 patients with acute infections (41 bacterial, 23 viral, 17 parasitic, and 7 rickettsial) were tested by the ELISA method for antinuclear antibodies (ANA) 8 Pro, and Abs to thyroid peroxidase (TPO), thyroglobulin, phospholipids, annexin-V, laminin, anti-Saccharomyces cervisiae (ASCA), and prothrombin, along with 80 normal controls. Elevated titers of Abs to annexin-V and prothrombin were the most prevalent in viral, parasitic, and rickettsial infections and to laminin in viral and parasitic infections. Elevated titers of ASCA and ANA were found in viral and bacterial infections. Antiphospholipid Abs were found in parasitic and Q-fever infections. Thirty-four individuals harbored elevated titers of at least two Abs. An autoAb burden was detected in individuals with hepatitis A, hepatitis B, toxoplasma or Q-fever infections. In nonautoimmune individuals with various (bacterial, viral, parasitic, and rickettsial) infections, elevated titers of Abs to annexin-V, prothrombin, laminin, ASCA, ANA, and phospholipids were most frequently detected.
Suehara, Yasuhito; Takamatsu, Hiroyuki; Fukumoto, Kota; Fujisawa, Manabu; Narita, Kentaro; Usui, Yoshiaki; Takeuchi, Masami; Endean, Kelly; Matsue, Kosei
Immunoglobulin (Ig) heavy/light chain (HLC) assays enable the separate quantification of the different light chain types of each Ig class. We retrospectively analyzed the correlation of heavy/light chain ratio (HLCR) with clinical status and its impact on outcome in 120 patients with multiple myeloma (MM). Abnormal HLCR was seen more frequently in patients with poorer myeloma response, and it appeared to be more sensitive for detecting clonality in IgA myeloma compared to IgG myeloma after treatment. Among the 85 patients who achieved ≥VGPR, the patients remained HLCR abnormal were showed significantly shorter overall survival (OS) compared to those achieving a normal HLCR (not reached vs 55.5 months, P = 0.032). This correlation was seen in IgA myeloma patients (not reached vs 30.1 months, P = 0.014), but not in IgG myeloma patients when patients were analyzed separately. Univariate and multivariate analysis of factors that may affect survival identified abnormal HLCR at the best response as the only independent risk factor (hazard ratio, 4.7; 95% confidence interval, 1.4 - 15.26; P = 0.012) for shorter OS in this subset of patients. This study highlighted the HLC assay as a prognostic predictor in patients with IgA myeloma.
Zaenker, Pauline; Ziman, Melanie R
Current diagnostic techniques used for the early detection of cancers are successful but subject to detection bias. A recent focus lies in the development of more accurate diagnostic tools. An increase in serologic autoantibody levels has been shown to precede the development of cancer disease symptoms. Therefore, autoantibody levels in patient blood serum have been proposed as diagnostic biomarkers for early-stage diagnosis of cancers. Their clinical application has, however, been hindered by low sensitivity, specificity, and low predictive value scores. These scores have been shown to improve when panels of multiple diagnostic autoantibody biomarkers are used. A five-marker biomarker panel has been shown to increase the sensitivity of prostate cancer diagnosis to 95% as compared with 12.2% for prostate-specific antigen alone. New potential biomarker panels were also discovered for lung, colon, and stomach cancer diagnosis with sensitivity of 76%, 65.4%, and 50.8%, respectively. Studies in breast and liver cancer, however, seem to favor single markers, namely α-2-HS-glycoprotein and des-γ-carboxyprothrombin with sensitivities of 79% and 89% for the early detection of the cancers. The aim of this review is to discuss the relevance of autoantibodies in cancer diagnosis and to outline the current methodologies used in the detection of autoantibodies. The review concludes with a discussion of the autoantibodies currently used in the diagnosis of cancers of the prostate, breast, lung, colon, stomach, and liver. A discussion of the potential future use of autoantibodies as diagnostic cancer biomarkers is also included in this review.
Bizzaro, N; Villalta, D; Tonutti, E; Doria, A; Tampoia, M; Bassetti, D; Tozzoli, R
An association between celiac disease (CD) and other autoimmune diseases such as connective tissue diseases (CTD), inflammatory bowel diseases (IBD), and primary biliary cirrhosis (PBC) has been reported in several studies. However, a high rate of false positives in autoantibody testing was noted, especially when tissue transglutaminase (tTG) from guinea pig liver was used. Thus, the real prevalence of CD in CTD, IBD, and PBC is unclear. In a case-control study, 400 patients with CTD, 170 with IBD, 48 with PBC, and 120 healthy subjects were investigated for CD by the analysis of IgA and IgG tTG antibodies using the more specific human recombinant tTG immunoenzymatic assay. Patients and controls with positive findings were further tested for antiendomysial antibodies by indirect immunofluorescence and HLA typing, and those found positive by either of these tests underwent duodenal biopsy to confirm a possible diagnosis of CD. Twelve patients were positive for IgA or IgG tTG antibodies, showing an overall prevalence of 1.9%. Only 1 healthy subject (0.8%) had a low level positive reaction for IgA anti-tTG. Among the 12 patients and the healthy subject, only 2 (1 SLE and 1 ulcerative colitis patient) were subsequently confirmed to be affected with CD by positive EMA, HLA, and small bowel biopsy findings. The highest rate of false positives was found in PBC patients (10.4%). For these reasons, serological screening testing for CD is not recommended in CTD patients or in subjects affected with IBD or PBC, unless there is a relevant clinical suspicion of CD.
Navi, Daniel; Michael, Daniel J; Fazel, Nasim
A 73-year-old man was admitted to the University of California Davis Medical Center for treatment of a pleural effusion and congestive heart failure. His hospital course was complicated by asymptomatic sustained ventricular tachycardia requiring placement of an implantable cardiac defibrillator. The patient was treated with vancomycin and cefazolin during the procedure. After 3 days he developed tense vesicles over the dorsal aspect of the hands. Perilesional skin biopsy showed subepidermal cleavage with a neutrophilic infiltrate. Direct immunofluorescence revealed granular IgA and C3 deposition along the dermal epidermal junction. A diagnosis of drug-induced linear IgA bullous dermatosis secondary to vancomycin was established. Linear IgA bullous dermatosis is a rare autoimmune blistering disorder with clinical features that can overlap with bullous pemphigoid and dermatitis herpetiformis. Drug-induced linear IgA bullous dermatosis is a less common variant that is correspondingly less well characterized. Although a variety of medications have been implicated, vancomycin is the most common associated drug.
Chung, Brian K; Guevel, Bardia T; Reynolds, Gary M; Gupta Udatha, D B R K; Henriksen, Eva Kristine Klemsdal; Stamataki, Zania; Hirschfield, Gideon M; Karlsen, Tom Hemming; Liaskou, Evaggelia
Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are immune-mediated biliary diseases that demonstrate prominent and restricted genetic association with human leukocyte antigen (HLA) alleles. In PBC, anti-mitochondrial antibodies (AMA) are specific and used as diagnostic biomarkers. PSC-relevant auto-antibodies remain controversial despite a distinct HLA association that mirrors archetypical auto-antigen driven disorders. Herein, we compared antibody-secreting B cells (ASCs) in PSC and PBC liver explants to determine if liver-infiltrating ASCs represent an opportune and novel source of disease-relevant auto-antibodies. Using enzymatic digestion and mechanical disruption, liver mononuclear cells (LIMCs) were isolated from fresh PSC and PBC explants and plasmablast (CD19+CD27+CD38(hi)CD138-) and plasma cell (CD19+CD27+CD38(hi)CD138+) ASCs were enumerated by flow cytometry. We observed 45-fold fewer plasma cells in PSC explants (n = 9) compared to PBC samples (n = 5, p < 0.01) and 10-fold fewer IgA-, IgG- and IgM-positive ASCs (p < 0.05). Liver-infiltrating ASCs from PSC and PBC explants were functional and produced similar concentrations of IgA, IgG and IgM following 2 weeks of culture. Antibody production by PBC ASCs (n = 3) was disease-specific as AMA to pyruvate dehydrogenase complex E2 subunit (PDC-E2) was detected by immunostaining, immunoblotting and ELISA. Antibody profiling of PSC supernatants (n = 9) using full-length recombinant human protein arrays (Cambridge Protein Arrays) revealed reactivities to nucleolar protein 3 (5/9) and hematopoietic cell-specific Lyn substrate 1 (3/9). Array analysis of PBC supernatants (n = 3) detected reactivities to PDC-E2 and hexokinase 1 (3/3). In conclusion, we detected unique frequencies of liver-infiltrating ASCs in PSC and PBC and in so doing, highlight a feasible approach for understanding disease-relevant antibodies in PSC.
Tanimura, Kenji; Jin, Hui; Suenaga, Tadahiro; Morikami, Satoko; Arase, Noriko; Kishida, Kazuki; Hirayasu, Kouyuki; Kohyama, Masako; Ebina, Yasuhiko; Yasuda, Shinsuke; Horita, Tetsuya; Takasugi, Kiyoshi; Ohmura, Koichiro; Yamamoto, Ken; Katayama, Ichiro; Sasazuki, Takehiko; Lanier, Lewis L.; Atsumi, Tatsuya; Yamada, Hideto
Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy complications. β2-glycoprotein I (β2GPI) complexed with phospholipid is recognized as a major target for autoantibodies in APS; however, less than half the patients with clinical manifestations of APS possess autoantibodies against the complexes. Therefore, the range of autoantigens involved in APS remains unclear. Recently, we found that human leukocyte antigen (HLA) class II molecules transport misfolded cellular proteins to the cell surface via association with their peptide-binding grooves. Furthermore, immunoglobulin G heavy chain/HLA class II complexes were specific targets for autoantibodies in rheumatoid arthritis. Here, we demonstrate that intact β2GPI, not peptide, forms a complex with HLA class II molecules. Strikingly, 100 (83.3%) of the 120 APS patients analyzed, including those whose antiphospholipid antibody titers were within normal range, possessed autoantibodies that recognize β2GPI/HLA class II complexes in the absence of phospholipids. In situ association between β2GPI and HLA class II was observed in placental tissues of APS patients but not in healthy controls. Furthermore, autoantibodies against β2GPI/HLA class II complexes mediated complement-dependent cytotoxicity against cells expressing the complexes. These data suggest that β2GPI/HLA class II complexes are a target in APS that might be involved in the pathogenesis. PMID:25733579
Tanimura, Kenji; Jin, Hui; Suenaga, Tadahiro; Morikami, Satoko; Arase, Noriko; Kishida, Kazuki; Hirayasu, Kouyuki; Kohyama, Masako; Ebina, Yasuhiko; Yasuda, Shinsuke; Horita, Tetsuya; Takasugi, Kiyoshi; Ohmura, Koichiro; Yamamoto, Ken; Katayama, Ichiro; Sasazuki, Takehiko; Lanier, Lewis L; Atsumi, Tatsuya; Yamada, Hideto; Arase, Hisashi
Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy complications. β2-glycoprotein I (β2GPI) complexed with phospholipid is recognized as a major target for autoantibodies in APS; however, less than half the patients with clinical manifestations of APS possess autoantibodies against the complexes. Therefore, the range of autoantigens involved in APS remains unclear. Recently, we found that human leukocyte antigen (HLA) class II molecules transport misfolded cellular proteins to the cell surface via association with their peptide-binding grooves. Furthermore, immunoglobulin G heavy chain/HLA class II complexes were specific targets for autoantibodies in rheumatoid arthritis. Here, we demonstrate that intact β2GPI, not peptide, forms a complex with HLA class II molecules. Strikingly, 100 (83.3%) of the 120 APS patients analyzed, including those whose antiphospholipid antibody titers were within normal range, possessed autoantibodies that recognize β2GPI/HLA class II complexes in the absence of phospholipids. In situ association between β2GPI and HLA class II was observed in placental tissues of APS patients but not in healthy controls. Furthermore, autoantibodies against β2GPI/HLA class II complexes mediated complement-dependent cytotoxicity against cells expressing the complexes. These data suggest that β2GPI/HLA class II complexes are a target in APS that might be involved in the pathogenesis.
Prakash, S; Kanjanabuch, T; Austin, P C; Croxford, R; Hsu, C-Y; Choi, A I; Cattran, D C
Local variations in patient demographics and medical practice can contribute to differences in renal outcomes in patients with IgA nephropathy. We report the experiences of two groups of Asians with IgA nephropathy across continents. We retrospectively examined two cohorts of Asian patients with IgA nephropathy from The King Chulalongkorn Memorial Hospital registry, Thailand (1994 - 2005), and The Metropolitan Toronto Glomerulonephritis registry, Canada (1975 - 2006), and compared their baseline characteristics. Slope of estimated glomerular filtration rate (eGFR) in each group was approximated using separate repeated measures regression models for each country. There were 152 Canadian and 76 Thai patients. At the time of first presentation, Thai patients were more likely to be female (63.2 vs. 44.1%, p = 0.01), have less baseline proteinuria (1.2 vs. 1.7 g/d, p = 0.08) and more likely to receive angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) (64.0 vs. 15.2%, p < 0.01), or prednisone (41.3 vs. 4.6%, p < 0.01). The annual change in estimated glomerular filtration rate (eGFR) for the Thai and Canadian groups were -0.82 ml/min/1.73 m2/year and -3.35 ml/min/1.73 m2/year, respectively, after adjustment for age, sex, mean arterial pressure (MAP), proteinuria, body mass index, Haas histological grade, chronicity scores and baseline medications. Although disease severity was similar among IgA nephropathy patients in Canada and Thailand, more Thai patients were on ACE-I/ARB or prednisone therapy at baseline. Further prospective research is needed to explore international differences in demographic and environmental factors, health resources, and disease management to determine how they may impact long-term outcomes in Asians with IgA nephropathy.
Suzuki, Hitoshi; Suzuki, Yusuke; Novak, Jan; Tomino, Yasuhiko
IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis in the world. IgAN is characterized by the mesangial accumulation of immune complexes containing IgA1, usually with co-deposits of complement C3 and variable IgG and/or IgM. Although more than 40 years have passed since IgAN was first described, the mechanisms underlying the disease development are not fully understood. Small-animal experimental models of IgAN can be very helpful in studies of IgAN, but development of these models has been hindered by the fact that only humans and hominoid primates have IgA1 subclass. Thus, multiple models have been developed, that may be helpful in studies of some specific aspects of IgAN. These models include a spontaneous animal model of IgAN, the ddY mouse first reported in 1985. These mice show mild proteinuria without hematuria, and glomerular IgA deposits, with a highly variable incidence and degree of glomerular injury, due to the heterogeneous genetic background. To obtain a murine line consistently developing IgAN, we intercrossed an earlyonset group of ddY mice, in which the development of IgAN includes mesangial IgA deposits and glomerular injury. After selective intercrossing for >20 generations, we established a novel 100% early-onset grouped ddY murine model. All grouped ddY mice develop proteinuria within eight weeks of age. The grouped ddY mouse model can be a useful tool for analysis of multiple aspects of the pathogenesis of IgAN and may aid in assessment of some approaches for the treatment of IgAN. PMID:25722731
Lleo, Ana; Invernizzi, Pietro; Gao, Bin; Podda, Mauro; Gershwin, M Eric
The critical function of the immune system is to discriminate self from non-self. Tolerance against self-antigens is a highly regulated process and, in order to maintain it, the immune system must be able to distinguish self-reactive lymphocytes as they develop. The presence of autoantibodies is the consequence of breakdown of tolerance and, although they are an important serological feature of autoimmune diseases, their presence is not exclusive of these conditions. Antibodies against self-antigens are also found in cancer, during massive tissue damage and even in healthy subjects. Natural autoantibodies provide immediate protection against infection and also prevent inflammation by facilitating the clearance of oxidized lipids, oxidized proteins, and apoptotic cells; their role in development of autoimmunity is still unclear. Detection of serum autoantibodies in clinical practice has become more available to clinicians worldwide while providing a powerful diagnostic tool. This review discusses the clinical significance of autoantibodies, their pathogenic mechanisms in autoimmune diseases and, finally, illustrates the technology available for appropriate autoantibody detection.
Goidl, E A; Michelis, M A; Siskind, G W; Weksler, M E
Three experimental models were used to compare the ease of inducing autoantibodies in young and old mice. Autoantibody to thyroglobulin (Tg) induced by immunization with cross-reactive xenogeneic Tg in Freund's complete adjuvant and autoerythrocyte antibody induced by the injection of xenogeneic erythrocytes were studied in C57Bl/6 and BALB/c male mice. In both strains, the anti-thyroglobulin antibody response to lower doses of xenogeneic Tg was significantly lower in old as compared with young animals. There were no detectable differences in incidence or strength of the direct Coombs' test following the administration of rat erythrocytes to old or young animals. In contrast, anti-mouse erythrocyte autoantibody-secreting spleen cells, generated in culture and assayed on bromelin-treated mouse erythrocytes, were more numerous in cultures of spleen cells from old as compared with young mice. These results suggest that the regulation of the autoantibody production which is stimulated by cross-reactive antigens is under different control from the spontaneous age-related increase in autoantibodies. PMID:7021024
Charkiewicz, Karol; Zbucka-Kretowska, Monika; Goscik, Joanna; Wolczynski, Slawomir; Lemancewicz, Adam
Imbalance in the metabolites levels which can potentially be related to certain fetal chromosomal abnormalities can stimulate mother's immune response to produce autoantibodies directed against proteins. The aim of the study was to determine the concentration of 9000 autoantibodies in maternal plasma to detect fetal Down syndrome. Method. We performed 190 amniocenteses and found 10 patients with confirmed fetal Down syndrome (15th–18th weeks of gestation). For the purpose of our control we chose 11 women without confirmed chromosomal aberration. To assess the expression of autoantibodies in the blood plasma, we used a protein microarray, which allows for simultaneous determination of 9000 proteins per sample. Results. We revealed 213 statistically significant autoantibodies, whose expression decreased or increased in the study group with fetal Down syndrome. The second step was to create a classifier of Down syndrome pregnancy, which includes 14 antibodies. The predictive value of the classifier (specificity and sensitivity) is 100%, classification errors, 0%, cross-validation errors, 0%. Conclusion. Our findings suggest that the autoantibodies may play a role in the pathophysiology of Down syndrome pregnancy. Defining their potential as biochemical markers of Down syndrome pregnancy requires further investigation on larger group of patients. PMID:27042674
Charkiewicz, Karol; Zbucka-Kretowska, Monika; Goscik, Joanna; Wolczynski, Slawomir; Lemancewicz, Adam; Laudanski, Piotr
Imbalance in the metabolites levels which can potentially be related to certain fetal chromosomal abnormalities can stimulate mother's immune response to produce autoantibodies directed against proteins. The aim of the study was to determine the concentration of 9000 autoantibodies in maternal plasma to detect fetal Down syndrome. Method. We performed 190 amniocenteses and found 10 patients with confirmed fetal Down syndrome (15th-18th weeks of gestation). For the purpose of our control we chose 11 women without confirmed chromosomal aberration. To assess the expression of autoantibodies in the blood plasma, we used a protein microarray, which allows for simultaneous determination of 9000 proteins per sample. Results. We revealed 213 statistically significant autoantibodies, whose expression decreased or increased in the study group with fetal Down syndrome. The second step was to create a classifier of Down syndrome pregnancy, which includes 14 antibodies. The predictive value of the classifier (specificity and sensitivity) is 100%, classification errors, 0%, cross-validation errors, 0%. Conclusion. Our findings suggest that the autoantibodies may play a role in the pathophysiology of Down syndrome pregnancy. Defining their potential as biochemical markers of Down syndrome pregnancy requires further investigation on larger group of patients.
Chefdeville, Aude; Honnorat, Jérôme; Hampe, Christiane S.; Desestret, Virginie
In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-D-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation. Some of these autoantibodies, generally targeting ionotropic channels or their partner proteins, define clinical syndromes resembling models of pharmacological or genetic disruption of the corresponding antigen, suggesting a direct pathogenic role of the associated autoantibodies. Moreover, the associated neurological symptoms are usually immunotherapy-responsive, further arguing for a pathogenic effect of the antibodies. Some studies have shown that some patients’ antibodies may have structural and functional in vitro effects on the targeted antigens. Definite proof of the pathogenicity of these autoantibodies has been obtained for just a few through passive transfer experiments in animal models. In this review we present existing and converging evidence suggesting a pathogenic role of some autoantibodies directed against neuronal cell-surface antigens observed in patients with central nervous system disorders. We describe the main clinical symptoms characterizing the patients and discuss conflicting arguments regarding the pathogenicity of these antibodies. PMID:26918657
Radic, Marko; Herrmann, Martin; van der Vlag, Johan; Rekvig, Ole Petter
In the 53 years since the discovery of anti-DNA autoantibodies in lupus [1, 2, 3] , recalcitrant questions have been pondered and possible answers have been debated. The discovery of anti-DNA autoantibodies presented many puzzles: How is immunological tolerance to native B-form DNA broken? What elicits characteristic systemic lupus erythematosus (SLE) autoantibodies? Which of the diverse anti-nuclear reactivities are pathogenic? What is the role of autoantibodies in the clinical presentation of disease? How do genetic predisposition and environmental triggers contribute to SLE? These questions were brought into focus by Professor David Stollar in an introductory presentation to an intense, three-day meeting set among the rugged and inspiring scenery of the Norwegian arctic coastline (the Scientific Program is included as supplemental File 1). Other participants presented and discussed topics directed to understanding the origin and clinico-pathological impact of autoantibodies to chromatin and phospholipid antigens. In the following, several aspects of the workshop are discussed.
Joo, HyeMee; Coquery, Christine; Xue, Yaming; Gayet, Ingrid; Dillon, Stacey R.; Punaro, Marilynn; Zurawski, Gerard; Banchereau, Jacques; Pascual, Virginia
The development of autoantibodies is a hallmark of systemic lupus erythematosus (SLE). SLE serum can induce monocyte differentiation into dendritic cells (DCs) in a type I IFN–dependent manner. Such SLE-DCs activate T cells, but whether they promote B cell responses is not known. In this study, we demonstrate that SLE-DCs can efficiently stimulate naive and memory B cells to differentiate into IgG- and IgA-plasmablasts (PBs) resembling those found in the blood of SLE patients. SLE-DC–mediated IgG-PB differentiation is dependent on B cell–activating factor (BAFF) and IL-10, whereas IgA-PB differentiation is dependent on a proliferation-inducing ligand (APRIL). Importantly, SLE-DCs express CD138 and trans-present CD138-bound APRIL to B cells, leading to the induction of IgA switching and PB differentiation in an IFN-α–independent manner. We further found that this mechanism of providing B cell help is relevant in vivo, as CD138-bound APRIL is expressed on blood monocytes from active SLE patients. Collectively, our study suggests that a direct myeloid DC–B cell interplay might contribute to the pathogenesis of SLE. PMID:22689824
Bealmear, Beverly; Ragheb, Samia; Xiong, Wen-Cheng; Lewis, Richard A.; Lisak, Robert P.; Mei, Lin
To determine if patients with myasthenia gravis (MG) have antibodies to agrin, a proteoglycan released by motor neurons and is critical for neuromuscular junction (NMJ) formation, we collected serum samples from 93 patients with MG with known status of antibodies to acetylcholine receptor (AChR), muscle specific kinase (MuSK) and lipoprotein-related 4 (LRP4) and samples from control subjects (healthy individuals and individuals with other diseases). Sera were assayed for antibodies to agrin. We found antibodies to agrin in 7 serum samples of MG patients. None of the 25 healthy controls and none of the 55 control neurological patients had agrin antibodies. Two of the four triple negative MG patients (i.e., no detectable AChR, MuSK or LRP4 antibodies, AChR-/MuSK-/LRP4-) had antibodies against agrin. In addition, agrin antibodies were detected in 5 out of 83 AChR+/MuSK-/LRP4- patients but were not found in the 6 patients with MuSK antibodies (AChR-/MuSK+/LRP4-). Sera from MG patients with agrin antibodies were able to recognize recombinant agrin in conditioned media and in transfected HEK293 cells. These sera also inhibited the agrin-induced MuSK phosphorylation and AChR clustering in muscle cells. Together, these observations indicate that agrin is another autoantigen in patients with MG and agrin autoantibodies may be pathogenic through inhibition of agrin/LRP4/MuSK signaling at the NMJ. PMID:24632822
Camilla, Roberta; Suzuki, Hitoshi; Daprà, Valentina; Loiacono, Elisa; Peruzzi, Licia; Amore, Alessandro; Ghiggeri, Gian Marco; Mazzucco, Gianna; Scolari, Francesco; Gharavi, Ali G.; Appel, Gerald B.; Troyanov, Stéphan; Novak, Jan; Julian, Bruce A.
Summary Background and objectives We assessed the activation of the oxidative stress pathway in patients with IgA nephropathy (IgAN), while evaluating the classic marker of the disease (galactose-deficient serum IgA1). Design, setting, participants, & measurements Sera from 292 patients and 69 healthy controls from Italy and the United States were assayed for advanced oxidation protein products (AOPPs), free sulfhydryl groups on albumin (SH-Alb), and IgA1 with galactose-deficient hinge-region O-glycans (Gd-IgA1). Gd-IgA1 was detected by binding to Helix aspersa agglutinin (HAA) and expressed as total Gd-IgA1 or as degree of galactose deficiency relative to a standard Gd-IgA1 myeloma protein (%HAA). Results Sera from IgAN patients showed higher levels of Gd-IgA1, %HAA, and AOPPs, but lower levels of SH-Alb in comparison to that from healthy controls. Serum levels of AOPPs significantly correlated with serum Gd-IgA1 and %HAA. The relationship between these biomarkers and clinical features at sampling and during follow-up was assessed in 62 patients with long-term follow-up. AOPPs and %HAA correlated with proteinuria at sampling and independently associated with subsequent proteinuria. Levels of AOPPs correlated with rate of decline in renal function after sampling. The combination of a high level of AOPPs and a high level of %HAA associated with decline in estimated GFR. Conclusions Serum levels of aberrantly glycosylated IgA1 are elevated and oxidative stress pathways are activated in patients with IgAN; the intensity of the stress correlated with expression and progression of the disease. We speculate that oxidative stress may modulate the nephrotoxicity of aberrantly glycosylated IgA1 in IgAN. PMID:21784819
Raskova Kafkova, Leona; Suzuki, Hitoshi; Tomana, Milan; Matousovic, Karel; Brown, Rhubell; Hall, Stacy; Sanders, John T.; Eison, T. Matthew; Moldoveanu, Zina; Novak, Lea; Novak, Zdenek; Mayne, Richard; Julian, Bruce A.; Mestecky, Jiri; Wyatt, Robert J.
Background. Circulating immune complexes (CIC) containing galactose (Gal)-deficient IgA1 from adults with IgA nephropathy (IgAN) induce proliferation of cultured mesangial cells, but activities of CIC from pediatric patients with the disease have not been studied. Methods. CIC of different sizes were isolated from sera of pediatric and adult IgAN patients and their effects on cultured human mesangial cells (MC) were assessed by measuring cellular proliferation, expression of IL-6 and IL-8 and laminin and phosphotyrosine signaling. Results. Large CIC from pediatric IgAN patients (>800 kDa) containing Gal-deficient IgA1 stimulated cellular proliferation, whereas in some patients, smaller CIC were inhibitory. Addition of stimulatory and inhibitory CIC to MC differentially altered phosphorylation patterns of three major tyrosine-phosphorylated proteins of molecular mass 37, 60 and 115 kDa. The stimulatory CIC transiently increased tyrosine-phosphorylation of the 37-kDa protein and decreased phosphorylation of the other two proteins, whereas the inhibitory CIC increased phosphorylation of all three proteins. Furthermore, we investigated the influence of IgA1-containing CIC from sera of children with IgAN with clinically active disease (i.e., abnormal urinalysis and/or serum creatinine concentration) or inactive disease (i.e., normal urinalysis and serum creatinine concentration) on the expression of IL-6 and IL-8 genes by mesangial cells. Real-time reverse transcription–polymerase chain reaction results showed that the CIC from a patient with active disease stimulated MC to express the two cytokine genes at higher levels than did the CIC from a patient with inactive disease. Moreover, stimulatory CIC increased production of the extracellular matrix protein laminin. Conclusion. These data indicate that sera of pediatric IgAN patients contain biologically active CIC with Gal-deficient IgA1. PMID:21828345
Cavazzana, Ilaria; Ceribelli, Angela; Taraborelli, Mara; Fredi, Micaela; Norman, Gary; Tincani, Angela; Satoh, Minoru; Franceschini, Franco
To analyze the prevalence, associations, and fine specificity of autoantibodies to primary biliary cirrhosis (PBC)-associated antigens (MIT3, Sp100, and gp210) in a cohort of Italian patients with systemic sclerosis (SSc). Sera samples from 201 patients with SSc were tested for antibodies to MIT3, gp210, and Sp100 by ELISA (the PBC screen). Anti-MIT3-positive sera were studied for IgG or IgA isotypes. All sera were analyzed by indirect immunofluorescence on HEp-2 cells and on rodent kidney/stomach/liver tissue sections in order to detect antinuclear and antimitochondrial antibodies (AMA). SSc was selected by American College of Rheumatology criteria and classified based on LeRoy's criteria. Forty-three (21.4%) sera samples were positive for PBC screen antibodies. Anti-MIT3 antibodies were detected in 36 samples, anti-Sp100 in 5, and anti-gp210 in 1 sample. The other 3 PBC screen-positive samples showed no specificity for the single antigens. PBC screen-positive patients more frequently showed a limited cutaneous SSc subtype (p = 0.04), anticentromere antibodies (ACA; p = 0.0013), elevated alkaline phosphatase (ALP) (p < 0.0001), PBC (p = 0.002), and AMA (p = 0.008). Teleangiectasia and calcinosis were less frequent in this group of patients. IgG+IgA anti-MIT3-positive patients had higher prevalence of AMA (p = 0.0035), diagnosis of PBC (p = 0.014), and increased ALP (p = 0.039), all considered biochemical markers of severe liver disease. PBC screen antibodies were detected in 20% of patients with SSc, strongly associated with ACA. ACA+/PBC screen+ patients had higher risk of developing PBC or elevation of ALP.
Song, Y W; Kang, E H
Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease, characterized by chronic, erosive polyarthritis and by the presence of various autoantibodies in serum and synovial fluid. Since rheumatoid factor (RF) was first described, a number of other autoantibodies have been discovered in RA patients. The autoantigens recognized by these autoantibodies include cartilage components, chaperones, enzymes, nuclear proteins and citrullinated proteins. However, the clinical significances and pathogenic roles of these antibodies are largely unknown except for RF and anticitrullinated protein antibodies (ACPAs), whose clinical usefulness has been acknowledged due to their acceptable sensitivities and specificities, and prognostic values. This review presents and discusses the current state of the art regarding RF and ACPA in RA.
Quist, Erin; Koepsell, Scott
Autoimmune hemolytic anemia is a rare disorder caused by autoreactive red blood cell (RBC) antibodies that destroy RBCs. Although autoimmune hemolytic anemia is rare, RBC autoantibodies are encountered frequently and can complicate transfusion workups, impede RBC alloantibody identification, delay distribution of compatible units, have variable clinical significance that ranges from benign to life-threatening, and may signal an underlying disease or disorder. In this review, we discuss the common presenting features of RBC autoantibodies, laboratory findings, ancillary studies that help the pathologist investigate the clinical significance of autoantibodies, and how to provide appropriate patient care and consultation for clinical colleagues. Pathologists must be mindful of, and knowledgeable about, this entity because it not only allows for direct clinical management but also can afford an opportunity to preemptively treat an otherwise silent malignancy or disorder.
Chruewkamlow, Nuttapol; Mahasongkram, Kodchakorn; Pata, Supansa; Chaiwarith, Romanee; Salee, Parichart; Supparatpinyo, Khuanchai; Kasinrerk, Watchara
Autoantibodies against interferon-gamma (IFN-γ) can cause immunodeficiency and are associated with various opportunistic infections. In the present study, we investigated other cellular immune parameters for a better understanding of the immunodeficiency condition in the patients. The numbers of WBC, monocytes and NK cells were increased in patients with anti-IFN-γ autoantibodies (AAbs). Upon TCR activation, T cell proliferation and IL-2 receptor of the patients remained intact. Nonetheless, the Th1 cytokine (IFN-γ and TNF-α) production was up-regulated. The production of Th2 (IL-4) and Th17 (IL-17) cytokines was unchanged. We suggest that, in addition to the presence of anti-IFN-γ autoantibodies, alterations in the cellular immune functions may also contribute to this immunodeficiency. PMID:26727515
Ran, Nina A.; Payne, Aimee S.
Rituximab, a monoclonal antibody targeting the B cell marker CD20, was initially approved in 1997 by the United States Food and Drug Administration (FDA) for the treatment of non-Hodgkin lymphoma. Since that time, rituximab has been FDA-approved for rheumatoid arthritis and vasculitides, such as granulomatosis with polyangiitis and microscopic polyangiitis. Additionally, rituximab has been used off-label in the treatment of numerous other autoimmune diseases, with notable success in pemphigus, an autoantibody-mediated skin blistering disease. The efficacy of rituximab therapy in pemphigus has spurred interest in its potential to treat other autoantibody-mediated diseases. This review summarizes the efficacy of rituximab in pemphigus and examines its off-label use in other select autoantibody-mediated diseases. PMID:28184292
Crandall, R. B.; Cebra, J. J.; Crandall, C. A.
The relative proportions of IgG, IgM and IgA immunoglobulin-containing cells were determined in the intestinal mucosa, spleen, popliteal lymph nodes and diaphragm of rabbits after a single infection and after hyperinfection with Trichinella spiralis. Staining with pairs of immunofluorescent reagents, specifically reactive with γ, μ or α immunoglobulin heavy chains and labelled with contrasting fluorochromes, permitted direct counting of cells containing two different immunoglobulin classes in a single tissue section. By employing two different pairs of reagents on adjacent sections the relative numbers of cells containing IgG, IgM and IgA were calculated. The observed cellular distribution of γ, μ and α heavy chains in the rabbit intestinal mucosa corresponded with the reported distribution in the human intestine. A relative increase in IgM-containing cells in the mucosa was observed after early infection with Trichinella, followed by an apparent increase in cells with IgG late in infection and after hyperinfection. The proportion of cells staining for IgA remained uniformly high in the intestine throughout the course of infection. The proportions of cells containing different immunoglobulin classes in the spleen contrasted with those observed in the intestinal mucosa, particularly with respect to cells containing α chain. IgA cells made up 2–10 per cent of the immunoglobulin-containing cells in the spleen as compared to 80–90 per cent in the intestinal mucosa. Most spleen sections showed an increase in IgM cells late in infection with Trichinella and after hyperinfection. The proportions of immunoglobulin-containing cells in the popliteal lymph nodes generally paralleled those observed in the spleen. Local cellular infiltration of the diaphragm occurred at the time of larval encystment. Immunoglobulin-containing cells were often prominent and the cellular distribution of immunoglobulin classes resembled that found in the spleen. The indirect fluorescent
van den Heuvel, Diana; Jansen, Michelle A E; Bell, Andrew I; Rickinson, Alan B; Jaddoe, Vincent W V; van Dongen, Jacques J M; Moll, Henriette A; van Zelm, Menno C
The EBV is known to persist in memory B cells, but it remains unclear how this affects cell numbers and humoral immunity. We here studied EBV persistence in memory B cell subsets and consequences on B cell memory in young children. EBV genome loads were quantified in 6 memory B cell subsets in EBV(+) adults. The effects of EBV infection on memory B cell numbers and vaccination responses were studied longitudinally in children within the Generation R population cohort between 14 mo and 6 yr of age. EBV genomes were more numerous in CD27(+)IgG(+), CD27(+)IgA(+), and CD27(-)IgA(+) memory B cells than in IgM-only, natural effector, and CD27(-)IgG(+) B cells. The blood counts of IgM-only, CD27(+)IgA(+), CD27(-)IgG(+), and CD27(+)IgG(+) memory B cells were significantly lower in EBV(+) children than in uninfected controls at 14 mo of age-the age when these cells peak in numbers. At 6 yr, all of these memory B cell counts had normalized, as had plasma IgG levels to previous primary measles and booster tetanus vaccinations. In conclusion, EBV persists predominantly in Ig class-switched memory B cells, even when derived from T cell-independent responses (CD27(-)IgA(+)), and EBV infection results in a transient depletion of these cells in young children.
Krause, Stephanie; Chmiel, Ruth; Bonifacio, Ezio; Scholz, Marlon; Powell, Michael; Furmaniak, Jadwiga; Rees Smith, Bernard; Ziegler, Anette-G; Achenbach, Peter
Autoantibodies to insulinoma-associated protein 2 (IA-2A) are associated with increased risk for type 1 diabetes. Here we examined IA-2A affinity and epitope specificity to assess heterogeneity in response intensity in relation to pathogenesis and diabetes risk in 50 children who were prospectively followed from birth. At first IA-2A appearance, affinity ranged from 10(7) to 10(11)L/mol and was high (>1.0×10(9)L/mol) in 41 (82%) children. IA-2A affinity was not associated with epitope specificity or HLA class II haplotype. On follow-up, affinity increased or remained high, and IA-2A were commonly against epitopes within the protein tyrosine phosphatase-like IA-2 domain and the homologue protein IA-2β. IA-2A were preceded or accompanied by other islet autoantibodies in 49 (98%) children, of which 34 progressed to diabetes. IA-2A affinity did not stratify diabetes risk. In conclusion, the IA-2A response in children is intense with rapid maturation against immunogenic epitopes and a strong association with diabetes development.
Hameed, Shihab; Ellard, Sian; Woodhead, Helen J; Neville, Kristen A; Walker, Jan L; Craig, Maria E; Armstrong, Taylor; Yu, Liping; Eisenbarth, George S; Hattersley, Andrew T; Verge, Charles F
Autoantibody-negative children diagnosed with type 1 diabetes might have unrecognized monogenic or type 2 diabetes. At diagnosis of type 1 diabetes (between ages 0.5 and 16.3 yr, n = 470), autoantibodies [glutamic acid decarboxylase (GAD), insulinoma-associated protein 2 (IA2), insulin autoantibodies (IAA), and/or islet cell antibody (ICA)] were positive (ab+) in 330 and negative in 37 (unknown in 103). Autoantibody-negative patients were retested at median diabetes duration of 3.2 yr (range 0.9-16.2) for autoantibodies (GAD, IA2, ZnT8), human leukocyte antigen (HLA) typing, non-fasting C-peptide, and sequencing of HNF4A, HNF1A, KCNJ11, and INS. Nineteen (5% of 367) remained persistently autoantibody negative (PAN), 17 were positive on repeat testing (PORT), and 1 refused retesting. No mutations were found in PORT. One PAN was heterozygous for P112L mutation in HNF1A and transferred from insulin to oral gliclazide. Another PAN transferred to metformin and the diagnosis was revised to type 2 diabetes. The remaining 17 PAN were indistinguishable from the ab+ group by clinical characteristics. HLA genotype was at high risk for type 1 diabetes in 82% of remaining PAN and 100% of PORT. After excluding patients with diabetes duration <1 yr, C-peptide was detectable more frequently in the remaining PAN (7/16) and PORT (6/17) than in a random selection of ab+ (3/28, p = 0.03). The diagnosis of type 1 diabetes should be reevaluated in PAN patients, because a subset has monogenic or type 2 diabetes. The remaining PAN have relatively preserved C-peptide compared with ab+, suggesting slower β-cell destruction, but a very high frequency of diabetogenic HLA, implying that type 1B (idiopathic) diabetes is rare. © 2010 John Wiley & Sons A/S.
Pfau, Jean C; Li, Sheng'ai; Holland, Sara; Sentissi, Jami J
Pulmonary fibrosis is a relentlessly progressive disease for which the etiology can be idiopathic or associated with environmental or occupational exposures. There is not a clear explanation for the chronic and progressive nature of the disease, leaving treatment and prevention options limited. However, there is increasing evidence of an autoimmune component, since fibrotic diseases are often accompanied by production of autoantibodies. Because exposure to silicates such as silica and asbestos can lead to both autoantibodies and pulmonary/pleural fibrosis, these exposures provide an excellent tool for examining the relationship between these outcomes. This study explored the possibility that autoantibodies induced by asbestos exposure in mice would affect fibroblast phenotype. L929 fibroblasts and primary lung fibroblasts were treated with serum IgG from asbestos- or saline-treated mice, and tested for binding using cell-based ELISA, and for phenotypic changes using immunofluorescence, laser scanning cytometry and Sirius Red collagen assay. Autoantibodies in the serum of C57Bl/6 mice exposed to asbestos (but not sera from untreated mice) bound to mouse fibroblasts. The autoantibodies induced differentiation to a myofibroblast phenotype, as demonstrated by increased expression of smooth muscle α-actin (SMA), which was lost when the serum was cleared of IgG. Cells treated with purified IgG of exposed mice produced excess collagen. Using ELISA, we tested serum antibody binding to DNA topoisomerase (Topo) I, vimentin, TGFβ-R, and PDGF-Rα. Antibodies to DNA Topo I and to PDGF-Rα were detected, both of which have been shown by others to be able to affect fibroblast phenotype. The anti-fibroblast antibodies (AFA) also induced STAT-1 activation, implicating the PDGF-R pathway as part of the response to AFA binding. These data support the hypothesis that asbestos induces AFA that modify fibroblast phenotype, and suggest a mechanism whereby autoantibodies may mediate
Kubo, Tomohiro; Uchida, Yuki; Watanabe, Yuko; Abe, Masahiro; Nakamura, Akira; Ono, Masao; Akira, Shizuo
Pathogens are sensed by Toll-like receptors (TLRs) expressed in leukocytes in the innate immune system. However, excess stimulation of TLR pathways is supposed to be connected with provocation of autoimmunity. We show that paired immunoglobulin (Ig)-like receptor B (PIR-B), an immunoreceptor tyrosine-based inhibitory motif–harboring receptor for major histocompatibility class I molecules, on relatively primitive B cells, B-1 cells, suppresses TLR9 signaling via Bruton's tyrosine kinase (Btk) dephosphorylation, which leads to attenuated activation of nuclear factor κB p65RelA but not p38 or Erk, and blocks the production of natural IgM antibodies, including anti-IgG Fc autoantibodies, particularly rheumatoid factor. The autoantibody production in PIR-B–deficient (Pirb−/−) mice was further augmented in combination with the Faslpr mutation, which might be linked to the development of autoimmune glomerulonephritis. These results show the critical link between TLR9-mediated sensing and a simultaneously evoked, PIR-B–mediated inhibitory circuit with a Btk intersection in B-1 cells, and suggest a novel way toward preventing pathogenic natural autoantibody production. PMID:19687229
Shah, Mona; Mamyrova, Gulnara; Huber, Adam M.; Rice, Madeline Murguia; Targoff, Ira N.; Miller, Frederick W.
Abstract The juvenile idiopathic inflammatory myopathies (JIIM) are systemic autoimmune diseases characterized by skeletal muscle weakness, characteristic rashes, and other systemic features. In follow-up to our study defining the major clinical subgroup phenotypes of JIIM, we compared demographics, clinical features, laboratory measures, and outcomes among myositis-specific autoantibody (MSA) subgroups, as well as with published data on adult idiopathic inflammatory myopathy patients enrolled in a separate natural history study. In the present study, of 430 patients enrolled in a nationwide registry study who had serum tested for myositis autoantibodies, 374 had either a single specific MSA (n = 253) or no identified MSA (n = 121) and were the subject of the present report. Following univariate analysis, we used random forest classification and exact logistic regression modeling to compare autoantibody subgroups. Anti-p155/140 autoantibodies were the most frequent subgroup, present in 32% of patients with juvenile dermatomyositis (JDM) or overlap myositis with JDM, followed by anti-MJ autoantibodies, which were seen in 20% of JIIM patients, primarily in JDM. Other MSAs, including anti-synthetase, anti-signal recognition particle (SRP), and anti-Mi-2, were present in only 10% of JIIM patients. Features that characterized the anti-p155/140 autoantibody subgroup included Gottron papules, malar rash, “shawl-sign” rash, photosensitivity, cuticular overgrowth, lowest creatine kinase (CK) levels, and a predominantly chronic illness course. The features that differed for patients with anti-MJ antibodies included muscle cramps, dysphonia, intermediate CK levels, a high frequency of hospitalization, and a monocyclic disease course. Patients with anti-synthetase antibodies had higher frequencies of interstitial lung disease, arthralgia, and “mechanic’s hands,” and had an older age at diagnosis. The anti-SRP group, which had exclusively juvenile polymyositis, was
Kaya, Selçuk; Demirci, Mustafa; Sesli Cetin, Emel; Cicioğlu Aridoğan, Buket; Sahin, Mehmet; Taş, Tekin; Korkmaz, Metin
Immunopathologic reactions may occur during toxocariasis due to tissue invasion and destruction by the secretions of larvae containing various enzymes with broad spectrum. The aim of this study was to search for autoantibodies such as anti-nuclear (ANA), anti-mitochondrial (AMA), anti-smooth muscle (ASMA), anti-neutrophil cytoplasmic (ANCA), anti-myeloperoxidase (MPO) and liver-kidney microsomal type 1 (LKM-1) antibodies in patients with toxocariasis, in order to investigate the role of toxocariasis as a trigger factor for autoimmune reactions. Forty patients (22 were male; mean age: 35.6 +/- 10.7 years) diagnosed as toxocariasis by clinical findings (abdominal pain, allergic symptoms and/or eosinophilia, without detection of any other causative agents, and without liver dysfunction, diabetes mellitus, cardiac or renal failure, and autoimmune disease) and in-house ELISA positivity and 32 healthy controls (16 were male; mean age: 40.7 +/- 11.2 years) were included to the study. ANA (screen), dsDNA, SS-A, SS-B, Scl-70, LKM-1, MPO and M2 autoantibodies have been investigated by ELISA (Euroimmun, Germany), while ANCA, AMA and ASMA antibodies by indirect immunofluorescence (IMMCO, NY) methods. Autoantibody positivity was detected in 18 (45%) patients of whom 11 yielded a single type, and 7 yielded > or = 2 types of autoantibodies. This rate was 12.5% for control group (two subjects were positive for ANA-Screen, one for anti-M2 and one for anti-LKM-1). The difference between the total positivity rates in patient and control groups was found statistically significant (chi2 = 5.72, p = 0.004). The most frequent autoantibody type among patients were ASMA (n = 6), followed by anti-dsDNA (n = 5), anti-M2 (n = 5), anti-SS-B (n = 4), anti-LKM-1 (n = 3), anti-SS-A (n = 2), ANCA (n = 2) and anti-MPO (n = 1). Positivity rate for ASMA was found statistically significant in patients' group compared to controls (chi2 = 12.24, p = 0.03), while there was no significant difference
Rider, Lisa G; Shah, Mona; Mamyrova, Gulnara; Huber, Adam M; Rice, Madeline Murguia; Targoff, Ira N; Miller, Frederick W
The juvenile idiopathic inflammatory myopathies (JIIM) are systemic autoimmune diseases characterized by skeletal muscle weakness, characteristic rashes, and other systemic features. In follow-up to our study defining the major clinical subgroup phenotypes of JIIM, we compared demographics, clinical features, laboratory measures, and outcomes among myositis-specific autoantibody (MSA) subgroups, as well as with published data on adult idiopathic inflammatory myopathy patients enrolled in a separate natural history study. In the present study, of 430 patients enrolled in a nationwide registry study who had serum tested for myositis autoantibodies, 374 had either a single specific MSA (n = 253) or no identified MSA (n = 121) and were the subject of the present report. Following univariate analysis, we used random forest classification and exact logistic regression modeling to compare autoantibody subgroups. Anti-p155/140 autoantibodies were the most frequent subgroup, present in 32% of patients with juvenile dermatomyositis (JDM) or overlap myositis with JDM, followed by anti-MJ autoantibodies, which were seen in 20% of JIIM patients, primarily in JDM. Other MSAs, including anti-synthetase, anti-signal recognition particle (SRP), and anti-Mi-2, were present in only 10% of JIIM patients. Features that characterized the anti-p155/140 autoantibody subgroup included Gottron papules, malar rash, "shawl-sign" rash, photosensitivity, cuticular overgrowth, lowest creatine kinase (CK) levels, and a predominantly chronic illness course. The features that differed for patients with anti-MJ antibodies included muscle cramps, dysphonia, intermediate CK levels, a high frequency of hospitalization, and a monocyclic disease course. Patients with anti-synthetase antibodies had higher frequencies of interstitial lung disease, arthralgia, and "mechanic's hands," and had an older age at diagnosis. The anti-SRP group, which had exclusively juvenile polymyositis, was characterized by high
Kraemer, Doris M; Tony, Hans-Peter
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease which is classically characterised by a variety of autoantibodies to deoxyribonucleic acid (DNA), ribonucleic acid (RNA), other nuclear and cytoplasmic antigens. Recently several novel autoantibodies against a variety of specific nuclear pore proteins have been described, including the nucleoporin p62. In this paper we evaluate anti-nucleoporin p62 antibodies by western blot analysis in 25 systemic lupus erythematosus patients. Six patients showed antibodies directed against nucleoporin p62. Our data indicate that p62 antibodies could be a useful additional marker in SLE. PMID:20648220
Rademacher, T W; Williams, P; Dwek, R A
The glycosylation of IgG results in many different glycoforms. A large body of correlative data (including remission of arthritis during pregnancy) has suggested that IgG molecules lacking galactose were associated with rheumatoid arthritis. We now demonstrate that agalactosyl IgG glycoforms are directly associated with pathogenicity in murine collagen-induced arthritis. We show that passive transfer of an acute synovitis in T-cell-primed mice can be enhanced by using IgG containing autoantibodies to type II collagen when the antibodies are present as the agalactosyl glycoform. Thus, nonpathogenic doses of autoantibodies can be made pathogenic by altering their glycosylation state. PMID:8016124
Nishie, Toshikazu; Miyaishi, Osamu; Azuma, Haruhito; Kameyama, Akihiko; Naruse, Chie; Hashimoto, Noriyoshi; Yokoyama, Hitoshi; Narimatsu, Hisashi; Wada, Takashi; Asano, Masahide
The glycosylation of glycoproteins is important for their biological activity, conformation and stability. Recent studies indicate that aberrant glycosylation causes various human disorders. Here we report that mice lacking beta-1,4-galactosyltransferase-I (beta4GalT-I), which transfers galactose from UDP-Gal to terminal GlcNAc of N- and O-glycans in a beta-1,4- linkage, developed IgA nephropathy (IgAN)-like disease. Urinary albumin levels were significantly increased in the beta4GalT-I-deficient mice. Hematuria was detected in some of the beta4GalT-I-deficient mice, suggesting impaired renal function. Furthermore, histological and immunohistochemical examination showed expanded mesangial matrix, IgA deposition with mesangial pattern and electron-dense deposits in the paramesangial regions in the beta4GalT-Ideficient mice. These results demonstrate that the beta4GalT-I-deficient mice developed IgANlike disease. Furthermore, high serum IgA levels with increased polymeric forms were detected. In humans, serum IgA derived from patients with IgAN has aberrant beta3-galactosylation and sialylation on its O-linked glycans of the hinge region. Mouse IgA does not have O-glycans of the hinge region and has several N-glycans. As expected, beta4-galactosylation on the N-glycans of the serum IgA of the beta4GalT-I-deficient mice was completely absent. This is the first report demonstrating that genetic remodeling of protein glycosylation causes IgAN. We suggest that aberrant beta4-galactosylation of serum IgA participates in the Nishie/Miyaishi/Azuma/Kameyama/Naruse/Hashimoto/Yokoyama/Narimatsu/Wada/Asano 126 development of IgAN, including deposition of IgA, polymerization of IgA, and glomerular injury after IgA deposition.
Gatselis, Nikolaos K; Zachou, Kalliopi; Norman, Gary L; Gabeta, Stella; Papamichalis, Panagiotis; Koukoulis, George K; Dalekos, George N
Primary biliary cirrhosis (PBC) is a chronic cholestatic disease characterized by the presence of antimitochondrial antibodies (AMA). PBC-specific antinuclear antibodies (ANA) have been characterized and associated with disease progression and outcome. We evaluated the clinical significance of the presence and serial changes in titers of AMA, PBC-specific ANA (anti-gp210, anti-sp100) and anti-chromatin antibodies. Over a median (IQR) period of 35 (36) months, 512 specimens were collected from 110 patients. Autoantibodies were detected by commercial ELISAs (INOVA Diagnostics). Biochemical, clinical, and histological status were included at initial presentation and during follow-up visits. The Mayo risk score was calculated as a prognostic index at each time point. Liver biopsy findings were classified according to Ludwig's classification and biochemical response to ursodeoxycholic acid was evaluated according to Pares. At baseline, AMA IgG and IgA, anti-gp210 IgG, anti-sp100 IgG and anti-chromatin IgG were detected in 92/110 (83.6%), 57/110 (51.8%), 5/110 (4.5%), 14/110 (12.7%), and 0/110 (0%) patients, respectively. Positivity for all autoantibodies apart from anti-chromatin, at baseline visit (n = 110 patients), in all tested sera (n = 512) as well as increased autoantibodies titers during follow-up were associated with biochemically and/or histologically advanced disease. A decrease of anti-sp100 titers but not of anti-gp210 titers during follow-up was associated with improvement of Mayo risk score (p = 0.025) and response to ursodeoxycholic acid (p = 0.016). These results suggest that detection of AMA and PBC-specific ANA was correlated with disease severity. Serial changes of anti-sp100 titers and not of anti-gp210 titers might prove useful for monitoring the disease course and treatment outcome.
Monfette, Ronald J.
Argues that college publications, including class schedules, must be accurate, timely, and easy to read and follow. Describes Schoolcraft College's unified format approach to publications marketing. Offers suggestions on the design, format, and distribution of class schedules. (DMM)
Hiki, Yoshiyuki; Horie, Akeyo; Yasuda, Yoshinari; Iwase, Hitoo; Sugiyama, Satoshi
Human immunoglobulin A1 (IgA1), which is the predominant subtype to be deposited in glomeruli in IgA nephropathy (IgAN), has a unique mucine-like structure in its hinge region. Namely, it contains O-glycans and proline-rich peptides We previously observed underglycosylation of the hinge region in serum and deposited IgA1 in IgAN. On the other hand, clinical development and exacerbation of IgAN are frequently preceded by episodes of upper respiratory tract infection, and palatine tonsils represent the predominant immunocompetent tissue of the upper respiratory tract. Therefore, we hypothesized that tonsils were one of the origins of glomerular IgA1 in IgAN, and investigated the O-glycan structure of IgA1 produced by tonsillar lymphocytes (tonsillar IgA1). A significant increase in asialo-agalacto type O-glycans was found in the tonsillar IgA1 hinge in IgAN. These results suggest that the tonsils produce underglycosylated IgA1 molecules, which enter the bloodstream and are then deposited in the glomeruli.
Rops, Angelique L; Figdor, Carl G; van der Schaaf, Alie; Tamboer, Wim P; Bakker, Marinka A; Berden, Jo H; Dijkman, Henry B P M; Steenbergen, Eric J; van der Vlag, Johan; van Spriel, Annemiek B
The tetraspanin protein CD37 is a leukocyte-specific transmembrane protein that is highly expressed on B cells. CD37-deficient (CD37(-/-)) mice exhibit a 15-fold increased level of immunoglobulin A (IgA) in serum and elevated numbers of IgA+ plasma cells in lymphoid organs. Here, we report that CD37(-/-) mice spontaneously develop renal pathology with characteristics of human IgA nephropathy. In young naïve CD37(-/-) mice, mild IgA deposition in glomeruli was observed. However, CD37(-/-) mice developed high titers of IgA immune complexes in serum during aging, which was associated with increased glomerular IgA deposition. Severe mesangial proliferation, fibrosis, and hyalinosis were apparent in aged CD37(-/-) mice, whereas albuminuria was mild. To further evaluate the role of CD37 in glomerular disease, we induced anti-glomerular basement membrane (GBM) nephritis in mice. CD37(-/-) mice developed higher IgA serum levels and glomerular deposits of anti-GBM IgA compared with wild-type mice. Importantly, glomerular macrophage and neutrophil influx was significantly higher in CD37(-/-) mice during both the heterologous and autologous phase of anti-GBM nephritis. Taken together, tetraspanin CD37 controls the formation of IgA-containing immune complexes and glomerular IgA deposition, which induces influx of inflammatory myeloid cells. Therefore, CD37 may protect against the development of IgA nephropathy.
Sánchez, D; Palová-Jelínková, L; Felsberg, J; Simsová, M; Pekáriková, A; Pecharová, B; Swoboda, I; Mothes, T; Mulder, C J J; Benes, Z; Tlaskalová-Hogenová, H; Tucková, L
Refractory coeliac disease (RCD) is a very rare and dangerous form of CD, in which gluten-free diet loses its therapeutic effect and the damage of intestinal mucosa persists. Because of the adherence to the diet, serological markers of CD [immunoglobulin A (IgA) antibodies against gliadin, tissue transglutaminase (tTG) and endomysium] are often missing in RCD patients. We found substantially elevated levels of IgA anti-calreticulin (CRT) antibodies in the sera of almost all RCD patients tested. These sera were negative for IgA antibodies to gliadin and tTG and only some of them showed IgA antibodies to enterocytes. Analysis of patients' IgA reactivity to CRT fragments (quarters and halves) by Western blotting revealed differences in the specificity of IgA antibodies between RCD and CD patients. We therefore used the Pepscan technique with synthetic overlapping decapeptides of CRT to characterize antigenic epitopes recognized by serum IgA antibodies of RCD patients. Employing this method we demonstrated several dominant antigenic epitopes recognized by IgA antibodies of RCD patients on the CRT molecule. Epitope GVTKAAEKQMKD was recognized predominantly by serum IgA of RCD patients. Our results suggest that testing for serum IgA antibodies against CRT and its selected peptide could be a very useful tool in RCD differential diagnosis.
Soares, Maria Fernanda
IgA Nephropathy (IgAN) is the commonest of the glomerular diseases in the world. Its progression rate of 30-40% of the cases em 20-30 years makes IgAN an important healthcare issue in Nephrology. Diagnosis of IgAN depends on biopsy findings, particularly at immunofluorescence microscopy. The frequence of IgAN diagnosis is variable in different populations and depends on screening and biopsy indication policies. IgAN pathogenesis is considered multifactorial; its primordial defect is the production of galactosis-deficient IgA molecules. This review paper discusses the most uptodate aspects of the pathogenesis, pathological classification and clinical implications of IgAN.
Out, T A; van Munster, P J; De Graeff, P A; Thé, T H; Vossen, J M; Zegers, B J
Concentrations of IgG2, IgG4 and IgE were low in 16, 24 and 20% of 25 persons with selective IgA deficiency. Fifty-two per cent had IgD concentrations below 5 iu/ml. Trends for association between any of these parameters and the presence of clinical symptoms were not significant. All patients, except one, had normal amounts of Ig-bearing lymphocytes in the blood. IgG1 antibodies against casein were increased in titre and frequency, whereas IgG4 antibodies were normal. Similar results were found in other sera from persons with selective IgA deficiency. PMID:3491694
Villalta, D; Alessio, M G; Tampoia, M; Tonutti, E; Brusca, I; Bagnasco, M; Pesce, G; Bizzaro, N
Clinical studies have estimated a 10- to 20-fold increased risk for celiac disease (CD) in patients with selective IgA deficiency (SIgAD). For this reason, screening for CD is mandatory in SIgAD patients, but it represents a special challenge since the specific IgA class antibodies against gliadin (AGA), endomysium (EMA), and tissue-transglutaminase (tTG) are not produced in patients with CD. IgG class counterparts of these antibodies may be informative; in particular IgG EMA has been demonstrated to be a valid marker for diagnosing CD in SIgAD cases, but it is not used much in clinical laboratories, because it is cumbersome and involves some technical difficulties. Even if it was widely used in clinical laboratories, the measuring of IgG AGA has shown a less-than-optimum diagnostic accuracy, so that now it tends to be substituted by tests for anti-tTG IgG, for which the few available studies have shown diagnostic performances superior to AGA. Since it is not known whether various available methods for measuring IgG anti-tTG antibodies offer similar diagnostic performances, we have compared the results obtained from nine second-generation commercial methods (D-tek, Phadia, Immco, Orgentec, Radim, Euroimmun, Inova, Aesku, Generic Assays), measuring IgG anti-tTG antibodies in 20 patients with CD and SIgAD and in 113 controls (9 patients with SIgAD without CD, 54 patients with chronic liver disease, and 50 healthy individuals). Diagnostic sensitivity, calculated by means of ROC plot analysis, ranged between 75% and 95%, and specificity ranged from 94% to 100%. In the same population, the diagnostic sensitivity and specificity of AGA IgG were 40% and 87%, respectively. Even though they perform differently, all IgG anti-tTG methods evaluated are reliable serological assays for the diagnosis of CD in SIgAD patients, with diagnostic accuracy superior to the AGA IgG method. The methods that use a mix of tTG and gliadin peptides as the antigenic preparation have a
Fernandes, Karina de Almeida Pinto; Galvis, Kely Hernández; Gomes, Anndressa Camillo da Matta Setubal; Nogueira, Osvania Maris; Felix, Paulo Antônio Oldani; Vargas, Thiago Jeunon de Sousa
Childhood linear immunoglobulin A dermatosis is a rare autoimmune vesiculobullous disease. It results in linear deposition of autoantibodies (immunoglobulin A) against antigens in the basal membrane zone, leading to subepidermal cleavage. Additional depositions of immunoglobulin G and complement-3 might occur. It is still debated whether concomitant findings of immunoglobulins A and G should be considered a subtype of this dermatosis or a new entity. Further studies are needed to recognize this clinical variant.
Fernandes, Karina de Almeida Pinto; Galvis, Kely Hernández; Gomes, Anndressa Camillo da Matta Setubal; Nogueira, Osvania Maris; Felix, Paulo Antônio Oldani; Vargas, Thiago Jeunon de Sousa
Childhood linear immunoglobulin A dermatosis is a rare autoimmune vesiculobullous disease. It results in linear deposition of autoantibodies (immunoglobulin A) against antigens in the basal membrane zone, leading to subepidermal cleavage. Additional depositions of immunoglobulin G and complement-3 might occur. It is still debated whether concomitant findings of immunoglobulins A and G should be considered a subtype of this dermatosis or a new entity. Further studies are needed to recognize this clinical variant. PMID:28300887
Ertekin, Özlem; Pirinçci, Şerife Şeyda; Öztürk, Selma
Antibody based techniques are widely used for the detection of aflatoxins which are potent toxins with a high rate of occurrence in many crops. We developed a murine monoclonal antibody of immunoglobulin A (IgA) isotype with a strong binding affinity to aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1). The antibody was effectively used in immunoaffinity column (IAC) and ELISA kit development. The performance of the IACs was compatible with AOAC performance standards for affinity columns (Test Method: AOAC 991.31). The total binding capacity of the IACs containing our antibody was 111 ng, 70 ng, 114 ng and 73 ng for AFB1, AFB2, and AFG1 andAFG2, respectively. Furthermore, the recovery rates of 5 ng of each AF derivative loaded to the IACs were determined as 104.9%, 82.4%, 85.5% and 70.7% for AFB1, AFB2, AFG1 and AFG2, respectively. As for the ELISA kit developed using non-oriented, purified IgA antibody, we observed a detection range of 2–50 µg/L with 40 min total test time. The monoclonal antibody developed in this research is hitherto the first presentation of quadruple antigen binding IgA monoclonal antibodies in mycotoxin analysis and also the first study of their utilization in ELISA and IACs. IgA antibodies are valuable alternatives for immunoassay development, in terms of both sensitivity and ease of preparation, since they do not require any orientation effort. PMID:27187470
Feriozzi, Sandro; Polci, Rosaria
The IgA nephropathy (IgAN) is a very common glomerulonephritis and can result in end-stage renal disease. From a clinical point of view, IgAN is characterised by repeated events of macrohaematuria associated with infections of the upper airways. In IgAN, the IgA released by the tonsillar lymphatic tissue into blood circulation are defective in glycosylation. These aberrant IgA can reach the glomeruli and deposit into mesangium causing an inflammation with cellular proliferation. The treatment is not yet well defined: steroids and immunosuppressive drugs are suggested in cases with a progressive disease. Tonsillectomy was proposed to reduce the infective events of upper airways and the lymphatic tissue producing undergalactosylated IgA. The experiences in literature coming from Asia report positive effects of tonsillectomy on IgAN. In patients with tonsillectomy, the renal signs improved (less haematuria and proteinuria) and the renal outcome was better (slower progression of renal damage). These were uncontrolled studies and tonsillectomy was associated with steroid and immunosuppressive treatment, so it is not possible to tell the real effect of tonsillectomy. In contrast, the European studies reported that the tonsillectomy was not associated with a better outcome of IgAN. A critical review of the subject reveals that most of the papers with positive results were uncontrolled retrospective experiences, while in a randomised controlled trial paper the advantages of tonsillectomy disappeared. In conclusion, this review, in agreement with the international guidelines, concludes that tonsillectomy does not play any role in the progression of IgAN.
IgA nephropathy is the most common form of glomerular disease among young adults. The aim of this study is to determine the correlation of IgG deposition with morphologic variables of Oxford classification and some clinical data of patients with IgA nephropathy (IgAN).A total of 114 biopsies were enrolled to the study (70.2% were male). Mean age of the patients was 37.7±13.6 years. This study showed that, IgG deposition intensity had not significant correlation with serum creatinine. No significant association of sex with IgG was found. There was not significant association of IgG deposits with age below and more that 40 years. There was not significant association of IgG deposit intensity with four morphologic variables of Oxford classification. Less studied published regarding the immunostaining findings in IgA nephropathy patients. Location of deposited immunoglobulin (mesangial versus mesangial-capillary) or the type of immunoglobulin (IgG or IgM) may have prognostic significant. More studies needs to find the clinical significance of immunostaining data.
Huter, Eva N.; Natarajan, Kannan; Torgerson, Troy R.; Glass, Deborah D.; Shevach, Ethan M.
Scurfy mice have a deletion in the Foxp3 gene, resulting in a failure to generate Foxp3+ regulatory T cells, and they subsequently develop severe CD4+ T-cell-mediated autoimmune inflammation. Multiple organs are involved, but the skin is one of the main organs affected. During the course of disease, Scurfy mice develop autoantibodies; however, the targeted antigens are unknown. In this study, we show that Scurfy mice develop autoantibodies directed against skin antigens. Using western blot analysis, we found that Scurfy serum reacted with proteins in total skin lysate, as well as in a keratinocyte lysate. Most of the Scurfy sera tested identified a major band at 50 kDa. Transfer of Scurfy CD4+ T cells into nu/nu mice yielded autoantibodies with similar reactivity. Further analysis using 2D western blots, followed by peptide mass fingerprinting, identified several keratins as targets. To confirm this observation, we chose one of the identified targets, keratin 14, and prepared recombinant proteins encompassing the N-terminal, middle, and C-terminal portions of the keratin 14 protein. Scurfy serum predominantly recognized the C-terminal fragment. Sera from patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, the human disease resulting from FOXP3 mutations, also recognized skin antigens, including keratin 14. Thus, the results of our study indicate that autoantibodies in Scurfy mice and patients with IPEX target keratins. PMID:20147963
Huter, Eva N; Natarajan, Kannan; Torgerson, Troy R; Glass, Deborah D; Shevach, Ethan M
Scurfy mice have a deletion in the Foxp3 gene, resulting in a failure to generate Foxp3(+) regulatory T cells, and they subsequently develop severe CD4(+) T-cell-mediated autoimmune inflammation. Multiple organs are involved, but the skin is one of the main organs affected. During the course of disease, Scurfy mice develop autoantibodies; however, the targeted antigens are unknown. In this study, we show that Scurfy mice develop autoantibodies directed against skin antigens. Using western blot analysis, we found that Scurfy serum reacted with proteins in total skin lysate, as well as in a keratinocyte lysate. Most of the Scurfy sera tested identified a major band at 50 kDa. Transfer of Scurfy CD4(+) T cells into nu/nu mice yielded autoantibodies with similar reactivity. Further analysis using 2D western blots, followed by peptide mass fingerprinting, identified several keratins as targets. To confirm this observation, we chose one of the identified targets, keratin 14, and prepared recombinant proteins encompassing the N-terminal, middle, and C-terminal portions of the keratin 14 protein. Scurfy serum predominantly recognized the C-terminal fragment. Sera from patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, the human disease resulting from FOXP3 mutations, also recognized skin antigens, including keratin 14. Thus, the results of our study indicate that autoantibodies in Scurfy mice and patients with IPEX target keratins.
Luo, Xu Min; Liu, Xin Yan; Tang, Ji Hong; Yang, Wei; Ni, Zhen Hua; Chen, Qing Ge; Wang, Xiongbiao
Chronic obstructive pulmonary disease (COPD) is an inflammation disorder and possibly an autoimmune disease. The components of the autoimmune response in the circulatory system are of considerable interest to clinicians. Because aberrations of costimulation status have been noted in COPD, the presence of autoantibodies to B7 costimulatory factor CD80 were investigated in a cohort of patients. Recombinant rs1CD80 (lacking the transmembrane domain of CD80) was used for Western blot analysis and ELISA to investigate the presence of autoantibodies in sera of patients with stable COPD and in controls without COPD. Cytokines IL-6 and IL-8 were detected using ELISA. Western blot revealed a specific band reacting to rs1CD80 by diluting sera pool of patients, which indicated the existence of autoantibodies to CD80. The serum level of anti-rs1CD80 was higher in patients with COPD than in controls(P=0.0185) and was positively correlated to the serum level of IL-6 (r=0.797, P<0.001) and IL-8 (r=0.608, P<0.001). There was a tendency that more higher level of anti-rs1CD80, more severe COPD stage. The existence of autoantibodies to costimulatory factor CD80 may suggest a pathogenic role of costimulatory factors in COPD. PMID:27867516
Luo, Xu Min; Liu, Xin Yan; Tang, Ji Hong; Yang, Wei; Ni, Zhen Hua; Chen, Qing Ge; Wang, Xiongbiao
Chronic obstructive pulmonary disease (COPD) is an inflammation disorder and possibly an autoimmune disease. The components of the autoimmune response in the circulatory system are of considerable interest to clinicians. Because aberrations of costimulation status have been noted in COPD, the presence of autoantibodies to B7 costimulatory factor CD80 were investigated in a cohort of patients. Recombinant rs1CD80 (lacking the transmembrane domain of CD80) was used for Western blot analysis and ELISA to investigate the presence of autoantibodies in sera of patients with stable COPD and in controls without COPD. Cytokines IL-6 and IL-8 were detected using ELISA. Western blot revealed a specific band reacting to rs1CD80 by diluting sera pool of patients, which indicated the existence of autoantibodies to CD80. The serum level of anti-rs1CD80 was higher in patients with COPD than in controls(P=0.0185) and was positively correlated to the serum level of IL-6 (r=0.797, P<0.001) and IL-8 (r=0.608, P<0.001). There was a tendency that more higher level of anti-rs1CD80, more severe COPD stage. The existence of autoantibodies to costimulatory factor CD80 may suggest a pathogenic role of costimulatory factors in COPD.
Ujiie, Hideyuki; Sasaoka, Tetsumasa; Izumi, Kentaro; Nishie, Wataru; Shinkuma, Satoru; Natsuga, Ken; Nakamura, Hideki; Shibaki, Akihiko; Shimizu, Hiroshi
Complement activation and subsequent recruitment of inflammatory cells at the dermal/epidermal junction are thought to be essential for blister formation in bullous pemphigoid (BP), an autoimmune blistering disease induced by autoantibodies against type XVII collagen (COL17); however, this theory does not fully explain the pathological features of BP. Recently, the involvement of complement-independent pathways has been proposed. To directly address the question of the necessity of the complement activation in blister formation, we generated C3-deficient COL17-humanized mice. First, we show that passive transfer of autoantibodies from BP patients induced blister formation in neonatal C3-deficient COL17-humanized mice without complement activation. By using newly generated human and murine mAbs against the pathogenic noncollagenous 16A domain of COL17 with high (human IgG1, murine IgG2), low (murine IgG1), or no (human IgG4) complement activation abilities, we demonstrate that the deposition of Abs, and not complements, is relevant to the induction of blister formation in neonatal and adult mice. Notably, passive transfer of BP autoantibodies reduced the amount of COL17 in lesional mice skin, as observed in cultured normal human keratinocytes treated with the same Abs. Moreover, the COL17 depletion was associated with a ubiquitin/proteasome pathway. In conclusion, the COL17 depletion induced by BP autoantibodies, and not complement activation, is essential for the blister formation under our experimental system.
Burbelo, Peter D.; O’Hanlon, Terrance P.
Purpose of review The purpose of this review is to highlight recent progress in autoantibody detection technologies and describe how these methods are providing novel information and insights into autoimmune disorders. Recent findings In recent years, alternative methods such as comprehensive phage display, fluid-phase immunoassays, and antigen microarrays have been developed for autoantigen discovery and profiling autoantibody responses. Compared to classic approaches such as Western blot and ELISA, these methods show improved diagnostic performance, the ability to measure antibody responses to multiple targets, and/or allow for more quantitative analyses. Specific notable findings include uncovering previously unrecognized autoantigens, the improved classification of patient clinical phenotypes, and the discovery of pathogenic autoantibodies promoting disease. Summary Advances in immunoassay technologies offer many opportunities for understanding the relationship between autoantibody detection and the myriad complex, clinical phenotypes characteristic of most autoimmune diseases. Further simplification and standardization of these technologies may allow routine integration into clinical practice with improved diagnostic and therapeutic outcomes. PMID:25203116
Gilmer, John; Harding, Tanner; Woods, Linda; Black, Brad; Flores, Raja; Pfau, Jean
Amphibole asbestos exposure is associated with the production of mesothelial cell autoantibodies (MCAA). These MCAA have been linked with pleural fibrotic disease in the asbestos exposed community of Libby, Montana, and induce collagen deposition by cultured mesothelial cells. However, the exact intracellular mechanism by which these autoantibodies cause an increase in collagen deposition remains unknown. This study sought to gain insight into the transcription factors involved in the collagen production after human mesothelial cells are exposed to MCAA. In this study, transcription factor activation profiles were generated from human mesothelial cells (Met5A) treated with serum from Libby subjects, and were compared to cells treated with serum cleared of IgG, and therefore containing no MCAA. Analysis of those profiles indicated C/EBP-beta and hypoxia inducible factor 1 alpha (HIF-1α) are significantly increased in the nucleus, indicating activation, due to MCAA exposure compared to controls. Inhibition of either of these transcription factors significantly reduced collagen 1 deposition by these cells following exposure to MCAA. These data suggest autoantibodies are directly involved in type I collagen deposition and may elucidate potential therapeutic targets for autoantibody mediated fibrosis.
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Multiple autoantibodies immunological test system. 866.5660 Section 866.5660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...
... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Multiple autoantibodies immunological test system. 866.5660 Section 866.5660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Thyroid autoantibody immunological test system. 866.5870 Section 866.5870 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Multiple autoantibodies immunological test system. 866.5660 Section 866.5660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...
... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Thyroid autoantibody immunological test system. 866.5870 Section 866.5870 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...
... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Multiple autoantibodies immunological test system. 866.5660 Section 866.5660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems §...
Sirotti, Silvia; Generali, Elena; Ceribelli, Angela; Isailovic, Natasa; De Santis, Maria; Selmi, Carlo
The sequencing of the human genome is now well recognized as the starting point of personalized medicine. Nonetheless, everyone is unique and can develop different phenotypes of the same disease, despite identical genotypes, as well illustrated by discordant monozygotic twins. To recognize these differences, one of the easiest and most familiar examples of biomarkers capable of identifying and predicting the outcome of patients is represented by serum autoantibodies. In this review, we will describe the concept of personalized medicine and discuss the predictive, prognostic and preventive role of antinuclear antibodies (ANA), anti-citrullinated peptide antibodies (ACPA), rare autoantibodies and anti-drug antibodies (ADA), to evaluate how these can help to identify different disease immune phenotypes and to choose the best option for treating and monitoring rheumatic patients in everyday practice. The importance of ANA resides in the prediction of clinical manifestations in systemic sclerosis and systemic lupus erythematosus and their association with malignancies. ACPA have a predictive role in rheumatoid arthritis, they are associated with the development of a more aggressive disease, extra-articular manifestations and premature mortality in RA patients; moreover, they are capable of predicting therapeutic response. Rare autoantibodies are associated with different disease manifestations and also with a greater incidence of cancer. The determination of ADA levels may be useful in patients where the clinical efficacy of TNF-α inhibitor has dropped, for the assessment of a right management. The resulting scenario supports serum autoantibodies as the cornerstone of personalized medicine in autoimmune diseases.
Giraud, M; Beaurain, G; Eymard, B; Tranchant, C; Gajdos, P; Garchon, H-J
Autoantibodies against the muscle acetylcholine receptor (AChR) play an essential role in the pathophysiology of autoimmune myasthenia gravis (MG). Their serum titers, however, vary considerably among patients. Our aim was to investigate whether their variation might be explained by genetic factors. Using different methods, we have obtained strong evidence for a three-locus association influencing autoantibody titers in MG patients with thymus hyperplasia or with a normal thymus. Two of the loci, one encoding the AChR alpha-subunit, the other encoding the alpha-chain of the class II antigen-presentation molecule, HLA-DQ, demonstrated interaction to determine high autoantibody titers. The third locus was associated with the 8.1 ancestral HLA haplotype. It exerted an additive effect and it is postulated to have a nonantigen specific immunoregulatory function. Our study demonstrates for the first time that polymorphism of an autoantigen gene may quantitatively modify the immune response against it. Altogether, the data lend support to a three-gene model to explain autoantibody expression in a subset of MG patients.
Suzuki, Tadaki; Ainai, Akira; Hasegawa, Hideki
Mucosal tissues are major targets for pathogens. The secretions covering mucosal surfaces contain several types of molecules that protect the host from infection. Among these, mucosal immunoglobulins, including secretory IgA (S-IgA) antibodies, are the major contributor to pathogen-specific immune responses. IgA is the primary antibody class found in many external secretions and has unique structural and functional features not observed in other antibody classes. Recently, extensive efforts have been made to develop novel vaccines that induce immunity via the mucosal route. S-IgA is a key molecule that underpins the mechanism of action of these mucosal vaccines. Thus, precise characterization of S-IgA induced by mucosal vaccines is important, if the latter are to be used successfully in a clinical setting. Intensive studies identified the fundamental characteristics of S-IgA, which was first discovered almost half a century ago. However, S-IgA itself has not gained much attention of late, despite its importance to mucosal immunity; therefore, some important questions remain. This review summarizes the current understanding of the molecular characteristics of S-IgA and its role in intranasal mucosal vaccines against influenza virus infection. Copyright © 2017 Elsevier Ltd. All rights reserved.
Gut, Paweł; Kosowicz, Jerzy; Ziemnicka, Katarzyna; Baczyk, Maciej; Sowiński, Jerzy
Addison disease (primary insufficience of adrenal cortex) characterized by clinical signs and symptoms associated with deficiency of adrenal hormones. The most frequent etiopathogenesis of Addison disease is related with autoimmunization. In sera of Addison patients are detectable autoantibodies against another endocrine glands. The aim of the study was evaluation of pituitary autoantibodies in Addison disease patients using immunoblotting methods. Studies were performed in 19 Addison disease patients, 16 women (age range: 28-63 yrs, median: 43.5 +/- 8.9) and 3 men (age range: 18-45 yrs, median: 30.6 +/- 9.8). All patients presented signs and symptoms typical of primary insufficiency of adrenal cortex. Sera of control subjects were obtained from 10 healthy blood donors, 7 women, 3 men (age range 21-45 yrs, median: 30.6 +/- 7.1). Incidence of pituitary autoantibodies was assessed by polyacrylamide electrophoresis gel and western-blotting. Pituitary microsomes were obtained from human pituitary tissues by ultracentrifugation and solubilisation in 1% desoxycholic acid. In 14 sera from 19 we detected autoantibodies against pituitary microsomal antigen 67 kDa, 12 sera were recting with 60 kDa and 10 sera with 55 kDa. It is important to note that 10 sera were reacting with 67 and 55 kDa, and 9 sera with 55, 60 and 67 kDa. In sera of Addison disease patients autoantibodies against pituitary microsomal antigens can be frequently detected. The most frequent are antibodies against 55, 60 and 67 kDa antigens.
Allenbach, Y; Benveniste, O
To date, there are four main groups of idiopathic inflammatory myopathies (IIM): polymyositis (PM), dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM) and sporadic inclusion body myositis; based on clinical presentation and muscle pathology. Nevertheless, important phenotypical differences (either muscular and/or extra-muscular manifestations) within a group persist. In recent years, the titration of different myositis-specific (or associated) auto-antibodies as a diagnostic tool has increased. This is an important step forward since it may facilitate, at a viable cost, the differential diagnosis between IIM and other myopathies. We have now routine access to assays for the detection of different antibodies. For example, IMNM are related to the presence of anti-SRP or anti-HMGCR. PM is associated with anti-synthetase antibodies (anti-Jo-1, PL-7, PL-12, OJ, and EJ) and DM with anti-Mi-2, anti-SAE, anti-TIF-1-γ and anti-NXP2 (both associated with cancer) or anti-MDA5 antibodies (associated with interstitial lung disease). Today, over 30 myositis specific and associated antibodies have been characterised, and all groups of myositis may present one of those auto-antibodies. Most of them allow identification of homogenous patient groups, more precisely than the classical international classifications of myositis. This implies that classification criteria could be modified accordingly, since these auto-antibodies delineate groups of patients suffering from myositis with consistent clinical phenotype (muscular and extra-muscular manifestations), common prognostic (cancer association, presence of interstitial lung disease, mortality and risk of relapse) and treatment responses. Nevertheless, since numerous auto-antibodies have been recently characterised, the exact prevalence of myositis specific antibodies remains to be documented, and research of new auto-antibodies in the remaining seronegative group is still needed.
Matesanz, F; Alcina, A
We report the development of an in vivo system to induce the generation, and study the potential role, of autoantibodies to the lymphokine interleukin-2 (IL-2). To elicit IL-2 autoantibodies, mice were immunized with purified fusion proteins containing the N-terminal region of different IL-2 allotypes, where major changes have been observed. This part of the IL-2 molecule includes a conserved sequence with an essential residue for interacting with the beta-chain of the heterotrimeric IL-2 receptor. Mice bearing an RF IL-2 allotype, immunized with several N-terminal IL-2 fusion proteins, produced IgG antibodies against Mus musculus, C57BL/6, Mus spretus and the self molecule RF IL-2, but there were large differences among then in reactivity. These N-terminal IL-2 immunogens break the maintenance of self tolerance possibly by the introduction of new T cell epitopes on self IL-2. The immunized mice developed a complex set of immunopathologies such as splenomegaly, haemolytic anaemia and lymphoadenopathy with a long latency period after the last immunization. These pathologies resembled those described for IL-2-deficient mice (IL-2(-/-)) and mice injected with anti-IL-2 receptor alpha-antibody. Human IL-2 autoantibodies have been detected in several immune-affected situations and therefore this model would be of interest to study the potential evolution of these autoantibodies in relation to immunopathology. The production of these autoantibodies against conserved epitopes of mouse IL-2 may facilitate studies on the structural homologies between different IL-2 allotypes and from various species, and could be applied to other cytokines. Copyright 1999 Academic Press.
Nakamura, Hideki; Kawakami, Atsushi; Eguchi, Katsumi
The major target organs of Sjögren's syndrome (SS) are lacrimal glands and salivary glands where prominent lymphocytic infiltration occurs, which may induce varying levels of autoantibody production. Multiple factors, including environmental stress, viral infection, hormonal imbalance, and apoptosis, are thought to be involved in the pathogenesis of SS. Production of anti-SS-A/Ro and anti-SS-B/La antibodies is thought to be regulated by the presentation of autoantigens in context with an aberrant expression pattern of human leukocyte antigen (HLA) in situ. Molecular mimicry with some viral sequences is also hypothesized. The apoptosis-resistance phenotype of B cells in labial salivary glands (LSGs) of SS is important in autoantibody production. CD40/CD40L (CD40 ligand) and Bcl-2 family proteins, in tandem with B cell-activating factor (BAFF), are supposed to protect infiltrating lymphocytes from apoptosis. Anti-muscarinic3 receptor antibody plays an important role in cholinergic hyperresponsiveness in SS. Fragmentation of autoantigens such as SS-B/La or alfa-fodrin during the process of apoptosis causes the redistribution of these autoantigens, leading to the production of autoantibodies in SS. In this review, the role of autoantibodies found in SS, corresponding to clinical aspects of each antibody as well as the mechanisms of production, is discussed.
Tsirogianni, Alexandra; Pipi, Elena; Soufleros, Konstantinos
Type 1 diabetes mellitus (T1DM) has been shown to be a disease characterized by immune-mediated destruction of the insulin-producing islet beta-cells (beta-cells) in the pancreas. Intensive studies, in both patients and animal models are trying to elucidate the specific antigenic targets that are responsible for islet cell autoimmunity. So far, the most important molecules that have been recognized are the native insulin, the 65-kDa form of glutamic acid decarboxylase (GAD(65)) and the insulinoma-antigen 2 (IA-2). Identification of those specific autoantibodies that are involved in the primary immunological events of the autoimmune disease process will allow the development of novel diagnostic procedures for early detection and initiation of potential therapy prior to irreversible loss of beta-cells. Within the framework of polyglandular disorders, T1DM may coexist with other organ specific autoimmune diseases such as autoimmune thyroid disease (ATD), autoimmune gastritis (AG), celiac disease (CD) and Addison's disease (AD), which are associated with the production of organ-specific autoantibodies. So, as a subset of patients with those autoantibodies will develop clinical disease, screening T1DM patients could prognosticate morbidity relative to unrecognised clinical entities. The close follow-up of patients with organ-specific autoantibodies could lead to seasonable identification of those requiring therapy.
Dzidic, Majda; Abrahamsson, Thomas R; Artacho, Alejandro; Björkstén, Bengt; Collado, Maria Carmen; Mira, Alex; Jenmalm, Maria C
Although a reduced gut microbiota diversity and low mucosal total IgA levels in infancy have been associated with allergy development, IgA responses to the gut microbiota have not yet been studied. We sought to determine the proportions of IgA coating together with the characterization of the dominant bacteria, bound to IgA or not, in infant stool samples in relation to allergy development. A combination of flow cytometric cell sorting and deep sequencing of the 16S rDNA gene was used to characterize the bacterial recognition patterns by IgA in stool samples collected at 1 and 12 months of age from children staying healthy or having allergic symptoms up to 7 years of age. The children with allergic manifestations, particularly asthma, during childhood had a lower proportion of IgA bound to fecal bacteria at 12 months of age compared with healthy children. These alterations cannot be attributed to differences in IgA levels or bacterial load between the 2 groups. Moreover, the bacterial targets of early IgA responses (including coating of the Bacteroides genus), as well as IgA recognition patterns, differed between healthy children and children with allergic manifestations. Altered IgA recognition patterns in children with allergy were observed already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breast-fed children. An aberrant IgA responsiveness to the gut microbiota during infancy precedes asthma and allergy development, possibly indicating an impaired mucosal barrier function in allergic children. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Chronic kidney disease (CKD) is a worldwide public health problem that affects millions of people from all racial and ethnic groups. Although CKD is not one specific disease, it is a comprehensive syndrome that includes IgA nephropathy. As reported by the Japanese Society of Nephrology, 13.0 million people have CKD. In Japan, major causes of end-stage kidney disease are type 2 diabetic nephropathy, chronic glomerulonephritis, especially IgA nephropathy, hypertensive nephrosclerosis, and polycystic kidney disease. IgA nephropathy is characterized by polymeric IgA1 with aberrant galactosylation (galactose-deficient IgA1) increased in the blood and deposited in the glomerular mesangial areas, as well as partially in the capillary walls. The tonsils are important as one of the responsible regions in this disease. The clarification of the mechanism of galactose-deficient IgA1 production will pave the way for the development of novel therapies. The results of future research are eagerly awaited. At present, the most important therapeutic goals in patients with IgA nephropathy are the control of hypertension, the decrease of urinary protein excretion, and the inhibition of progression to end-stage kidney disease. Several investigators have reported that renin-angiotensin-aldosterone system inhibitors reduce levels of urinary protein excretion and preserve renal function in patients with IgA nephropathy. In Japan, tonsillectomy and steroid pulse therapy are more effective for patients with IgA nephropathy.
Han, Seung Hyeok; Kang, Ea Wha; Kie, Jeong Hae; Yoo, Tae Hyun; Choi, Kyu Hun; Han, Dae-Suk; Kang, Shin-Wook
Although most cases of immunoglobulin A (IgA) nephropathy are idiopathic, several diseases are associated with IgA nephropathy. Of these, chronic liver disease resulting from hepatitis B or C virus infection has been reported as a secondary cause of IgA nephropathy. Recently, hepatitis A virus (HAV)-associated kidney disease has received attention because acute kidney injury can occur as a complication of HAV infection, generally caused by acute tubular necrosis or interstitial nephritis. However, unlike IgA nephropathy related to hepatitis B or C, HAV-associated IgA nephropathy is extremely rare and long-term outcomes have not been reported yet. We describe a case of spontaneous remission of IgA nephropathy associated with serologically documented HAV infection. The patient presented with microhematuria and moderate proteinuria, but acute kidney injury did not occur during active hepatic injury. Kidney biopsy specimens clearly showed mesangial IgA deposits with intact tubules and interstitium. Serum liver enzyme levels returned to reference values 1 month after the onset of acute hepatitis, but urinary protein excretion remained increased. Approximately 1 year later, urinary abnormalities were resolved and a second biopsy showed no mesangial IgA deposits. These findings suggest that IgA nephropathy can transiently accompany HAV infection, but may not progress to chronic glomerulonephritis after recovery from HAV. Copyright © 2010 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.
Ebefors, Kerstin; Liu, Peidi; Lassén, Emelie; Elvin, Johannes; Candemark, Emma; Levan, Kristina; Haraldsson, Börje; Nyström, Jenny
IgA nephropathy (IgAN) is the most common glomerulonephritis in the world, affecting close to a million people. Circulating galactose-deficient IgA (gd-IgA), present in patients with IgAN, form immune complex deposits in the glomerular mesangium causing local proliferation and matrix expansion. Intriguing though, individuals having gd-IgA deposits in the kidneys do not necessarily have signs of glomerular disease. Recurrence of IgAN only occurs in less than half of transplanted patients with IgAN, indicating that gd-IgA is not the only factor driving the disease. We hypothesize that, in addition to IgA complexes, patients with IgAN possess a subtype of mesangial cells highly susceptible to gd-IgA induced cell proliferation. To test the hypothesis, we designed a technique to culture primary mesangial cells from renal biopsies obtained from IgAN patients and controls. The cell response to gd-IgA treatment was then measured both on gene and protein level and the proliferation rate of the cells in response to PDGF was investigated. When treated with gd-IgA, mesangial cells from patients with IgAN express and release more PDGF compared to controls. In addition, the mesangial cells from patients with IgAN were more responsive to treatment with PDGF resulting in an increased proliferation rate of the cells compared to control. Mesangial cells cultured from patients with IgAN expressed and released more IL-6 than controls and had a higher expression of matrix genes. Both mesangial cells derived from patients with IgAN and controls increased their expressed TGFβ1 and CCL5 when treated with gd-IgA. We conclude that mesangial cells derived from IgAN patients have a mesangioproliferative phenotype with increased reactivity to IgA and that these cellular intrinsic properties may be important for the development of IgA nephropathy.
Lehoux, Sylvain; Mi, Rongjuan; Aryal, Rajindra P.; Wang, Yingchun; Schjoldager, Katrine T.-B. G.; Clausen, Henrik; van Die, Irma; Han, Yoosun; Chapman, Arlene B.; Cummings, Richard D.; Ju, Tongzhong
Immunoglobulin A nephropathy (IgAN) is the most common form of glomerulonephritis worldwide and is histologically characterized by the deposition of IgA1 and consequent inflammation in the glomerular mesangium. Prior studies suggested that serum IgA1 from IgAN patients contains aberrant, undergalactosylated O-glycans, for example, Tn antigen and its sialylated version, SialylTn (STn), but the mechanisms underlying aberrant O-glycosylation are not well understood. Here we have used serial lectin separation technologies, Western blot, enzymatic modifications, and mass spectrometry to explore whether there are different glycoforms of IgA1 in plasma from patients with IgAN and healthy individuals. Although total plasma IgA in IgAN patients was elevated ∼1.6-fold compared with that in healthy donors, IgA1 in all samples was unexpectedly separable into two distinct glycoforms: one with core 1 based O-glycans, and the other exclusively containing Tn/STn structures. Importantly, Tn antigen present on IgA1 from IgAN patients and controls was convertible into the core 1 structure in vitro by recombinant T-synthase. Our results demonstrate that undergalactosylation of O-glycans in IgA1 is not restricted to IgAN and suggest that in vivo inefficiency of T-synthase toward IgA1 in a subpopulation of B or plasma cells, as well as overall elevation of IgA, may contribute to IgAN pathogenesis. PMID:25071157
Background Although serum under-O-glycosylated IgA1 in IgA nephropathy (IgAN) patients may deposit more preferentially in glomeruli than heavily-O-glycosylated IgA1, the relationship between the glomerular IgA deposition level and the O-glycan profiles of serum IgA1 remains obscure. Methods Serum total under-O-glycosylated IgA1 levels were quantified in 32 IgAN patients by an enzyme-linked immunosorbent assay (ELISA) with Helix aspersa (HAA) lectin. Serum under-O-glycosylated polymeric IgA1 (pIgA1) was selectively measured by an original method using mouse Fcα/μ receptor (mFcα/μR) transfectant and flow cytometry (pIgA1 trap). The percentage area of IgA deposition in the whole glomeruli (Area-IgA) was quantified by image analysis on the immunofluorescence of biopsy specimens. Correlations were assessed between the Area-IgA and data from HAA-ELISA or pIgA1 trap. The relationships between clinical parameters and data from HAA-ELISA or pIgA1 trap were analyzed by data mining approach. Results While the under-O-glycosylated IgA1 levels in IgAN patients were significantly higher than those in healthy controls when measured (p < 0.05), there was no significant difference in under-O-glycosylated pIgA1. There was neither a correlation observed between the data from HAA-ELISA and pIgA1 trap (r2 = 0.09) in the IgAN patients (r2 = 0.005) nor was there a linear correlation between Area-IgA and data from HAA-ELISA or the pIgA1 trap (r2 = 0.005, 0.03, respectively). Contour plots of clinical parameters versus data from HAA-ELISA and the pIgA1 trap revealed that patients with a high score in each clinical parameter concentrated in specific areas, showing that patients with specific O-glycan profiles of IgA1 have similar clinical parameters. A decision tree analysis suggested that dominant immune complexes in glomeruli were consisted of: 1) IgA1-IgG and complements, 2) pIgA1 and complements, and 3) monomeric IgA1-IgA or aggregated monomeric IgA1. Conclusions
Ching, Kathryn H; Burbelo, Peter D; Tipton, Christopher; Wei, Chungwen; Petri, Michelle; Sanz, Ignacio; Iadarola, Michael J
Systemic lupus erythematosus is a chronic autoimmune disease of complex clinical presentation and etiology and is likely influenced by numerous genetic and environmental factors. While a large number of susceptibility genes have been identified, the production of antibodies against a distinct subset of nuclear proteins remains a primary distinguishing characteristic in disease diagnosis. However, the utility of autoantibody biomarkers for disease sub-classification and grouping remains elusive, in part, because of the difficulty in large scale profiling using a uniform, quantitative platform. In the present study serological profiles of several known SLE antigens, including Sm-D3, RNP-A, RNP-70k, Ro52, Ro60, and La, as well as other cytokine and neuronal antigens were obtained using the luciferase immunoprecipitation systems (LIPS) approach. The resulting autoantibody profiles revealed that 88% of a pilot cohort and 98% of a second independent cohort segregated into one of two distinct clusters defined by autoantibodies against Sm/anti-RNP or Ro/La autoantigens, proteins often involved in RNA binding activities. The Sm/RNP cluster was associated with a higher prevalence of serositis in comparison to the Ro/La cluster (P = 0.0022). However, from the available clinical information, no other clinical characteristics were associated with either cluster. In contrast, evaluation of autoantibodies on an individual basis revealed an association between anti-Sm (P = 0.006), RNP-A (P = 0.018) and RNP-70k (P = 0.010) autoantibodies and mucocutaneous symptoms and between anti-RNP-70k and musculoskeletal manifestations (P = 0.059). Serologically active, but clinically quiescent disease also had a higher prevalence of anti-IFN-α autoantibodies. Based on our findings that most SLE patients belong to either a Sm/RNP or Ro/La autoantigen cluster, these results suggest the possibility that alterations in RNA-RNA-binding protein interactions may play a critical
Liu, Jin; Bian, Lingling; Ji, Li; Chen, Yang; Chen, Heng; Gu, Yong; Ma, Bingqin; Gu, Wei; Xu, Xinyu; Shi, Yun; Wang, Jian; Zhu, Dalong; Sun, Zilin; Ma, Jianhua; Jin, Hui; Shi, Xing; Miao, Heng; Xin, Bing; Zhu, Yan; Zhang, Zhenwen; Bu, Ruifang; Xu, Lan; Shi, Guangde; Tang, Wei; Li, Wei; Zhou, Dongmei; Liang, Jun; Cheng, Xingbo; Shi, Bimin; Dong, Jixiang; Hu, Ji; Fang, Chen; Zhong, Shao; Yu, Weinan; Lu, Weiping; Wu, Chenguang; Qian, Li; Yu, Jiancheng; Gao, Jialin; Fei, Xiaoqiang; Zhang, Qingqing; Wang, Xueqin; Cui, Shiwei; Cheng, Jinluo; Xu, Ning; Wang, Guofeng; Han, Guoqing; Xu, Chunrong; Xie, Yun; An, Minmin; Zhang, Wei; Wang, Zhixiao; Cai, Yun; Fu, Qi; Fu, Yu; Zheng, Shuai; Yang, Fan; Hu, Qingfang; Dai, Hao; Jin, Yu; Zhang, Zheng; Xu, Kuanfeng; Li, Yifan; Shen, Jie; Zhou, Hongwen; He, Wei; Zheng, Xuqin; Han, Xiao; Yu, Liping; She, Jinxiong; Zhang, Mei; Yang, Tao
Type 1 diabetes mellitus is heterogeneous in many facets. The patients suffered from type 1 diabetes present several levels of islet function as well as variable number and type of islet-specific autoantibodies. This study was to investigate prevalence and heterogeneity of the islet autoantibodies and clinical phenotypes of type 1 diabetes mellitus; and also discussed the process of islet failure and its risk factors in Chinese type 1 diabetic patients. A total of 1,291 type 1 diabetic patients were enrolled in this study. Demographic information was collected. Laboratory tests including mixed-meal tolerance test, human leukocyte antigen alleles, hemoglobinA1c, lipids, thyroid function and islet autoantibodies were conducted. The frequency of islet-specific autoantibody in newly diagnosed T1DM patients (duration shorter than half year) was 73% in East China. According to binary logistic regressions, autoantibody positivity, longer duration and lower Body Mass Index were the risk factors of islet failure. As the disease developed, autoantibodies against glutamic acid decarboxylase declined as well as the other two autoantibodies against zinc transporter 8 and islet antigen 2. The decrease of autoantibodies was positively correlated with aggressive beta cell destruction. Autoantibodies can facilitate the identification of classic T1DM from other subtypes and predict the progression of islet failure. As there were obvious heterogeneity in autoantibodies and clinical manifestation in different phenotypes of the disease, we should take more factors into consideration when identifying type 1 diabetes mellitus.
Nickowitz, R E; Wozniak, R W; Schaffner, F; Worman, H J
Autoantibodies against nuclear membrane proteins have been identified in patients with primary biliary cirrhosis (PBC). The aim of the present study was to determine the incidence of these autoantibodies in patients with PBC and examine their significance. An assay using recombinant polypeptides was designed to unequivocally detect autoantibodies against gp210 and the lamin B receptor, integral proteins of the nuclear membranes. Autoantibodies against gp210 were detected in 15 of 159 patients with PBC and 0 of 46 controls. Autoantibodies against lamin B receptor were detected in 2 patients with PBC and 0 controls. The presence of these autoantibodies had a sensitivity of 11% and specificity of 100% for the diagnosis of PBC. Autoantibodies against gp210 were present in 4 of 19 (21%) patients with PBC who did not have detectable antimitochondrial antibodies. Patients with PBC and gp210 autoantibodies had a higher incidence of associated arthritis. Autoantibodies against gp210 and the lamin B receptor are present in approximately 10% of patients with PBC. These autoantibodies are highly specific for the diagnosis of PBC and may be useful in diagnosing individuals without antimitochondrial antibodies and in identifying a subgroup of patients with an increased incidence of associated arthritis.
Bingley, Polly J; Rafkin, Lisa E; Matheson, Della; Steck, Andrea K; Yu, Liping; Henderson, Courtney; Beam, Craig A; Boulware, David C
Islet autoantibody testing provides the basis for assessment of risk of progression to type 1 diabetes. We set out to determine the feasibility and acceptability of dried capillary blood spot-based screening to identify islet autoantibody-positive relatives potentially eligible for inclusion in prevention trials. Dried blood spot (DBS) and venous samples were collected from 229 relatives participating in the TrialNet Pathway to Prevention Study. Both samples were tested for glutamic acid decarboxylase, islet antigen 2, and zinc transporter 8 autoantibodies, and venous samples were additionally tested for insulin autoantibodies and islet cell antibodies. We defined multiple autoantibody positive as two or more autoantibodies in venous serum and DBS screen positive if one or more autoantibodies were detected. Participant questionnaires compared the sample collection methods. Of 44 relatives who were multiple autoantibody positive in venous samples, 42 (95.5%) were DBS screen positive, and DBS accurately detected 145 of 147 autoantibody-negative relatives (98.6%). Capillary blood sampling was perceived as more painful than venous blood draw, but 60% of participants would prefer initial screening using home fingerstick with clinic visits only required if autoantibodies were found. Capillary blood sampling could facilitate screening for type 1 diabetes prevention studies.
Fritzler, Marvin J
Rapid advances in diagnostic technologies used to detect autoantibodies have made it difficult for even the most modern laboratory to keep abreast of the changing approaches and platforms, not to mention the clinicians who are hard pressed to keep abreast of evolving diagnostic paradigms attended by these newer techniques. While autoantibody testing is traditionally considered to be primarily serving the realm of diagnostic medicine, there is little doubt that autoantibodies are also being recognized as an approach to providing prognostic and therapeutic information. Accordingly, along with related proteomics, genomics and metabolomics, it is taking on increasing importance in the realm of personalized medicine. In today's world of autoantibody diagnostics, overarching concerns about false-negative and false-positive autoantibodies tests cannot be summarily dismissed by citing pros or cons of any one technology or diagnostic platform, but often point to persisting gaps in our knowledge about, and understanding of, the origin and roles of autoantibodies. Before we can hope to completely understand the enigmas that attend the results of autoantibody diagnostic tests, perhaps it is time to step back and re-examine long-accepted paradigms and beliefs. This review will address some of the issues that impact on autoantibody detection technologies and some of the considerations and issues that will attend a new orthodoxy of autoantibody diagnostics. These issues will be addressed in the context of "bad" (pathogenic), "good" (protective) or "indifferent" (no apparent role in disease) autoantibodies.
Hattori, Naoki; Ishihara, Takashi; Matsuoka, Naoki; Saito, Takanori; Shimatsu, Akira
Macro-thyrotropin (TSH) is a high-molecular-weight form of TSH. Most cases of macro-TSH are TSH complexed with immunoglobulin G. This study was undertaken to characterize macro-TSH. Blood samples taken from patients with subclinical hypothyroidism were screened for the presence of macro-TSH with the polyethylene glycol method and confirmed with gel filtration chromatography. TSH receptor antibody was quantified with an electrochemiluminescence immunoassay. Binding studies were performed using (125)I-human TSH, and the specificity of anti-TSH autoantibodies was tested by displacement experiments using excess amounts of the unlabeled related peptides. Macro-TSH and serum TSH levels were evaluated twice over a one- to four-year interval. Sixteen patients (11 females and 5 males; aged 8-82 years) were diagnosed as having macro-TSH. None of the patients with macro-TSH tested positive for TSH receptor antibody. Judging from the affinity and the binding capacity of anti-TSH autoantibodies, two classes of binding sites were identified. Regarding specificity, there were anti-human TSH-β autoantibodies that were partially cross-reactive to bovine and/or rat TSH-β. There were also autoantibodies against human glycoprotein α, a common subunit among human TSH, luteinizing hormone, and follicle stimulating hormone. Macro-TSH persisted in 11/13 patients who could be reevaluated over a one- to four-year interval after the first evaluation. Serum TSH levels returned to normal in the remaining two patients whose macro-TSH disappeared. It is concluded that anti-human TSH autoantibodies are a major cause of macro-TSH and that macro-TSH may persist for a long time.
Murphy, Timothy F.; Kirkham, Charmaine; Jones, Megan M.; Sethi, Sanjay; Kong, Yong; Pettigrew, Melinda M.
Background. Immunoglobulin (Ig)A proteases of Haemophilus influenzae are highly specific endopeptidases that cleave the hinge region of human IgA1 and also mediate invasion and trafficking in human respiratory epithelial cells, facilitating persistence of H. influenzae. Little is known about the expression of IgA proteases in clinical settings of H. influenzae infection. Methods. We identified and characterized IgA protease genes in H. influenzae and studied their expression and proteolytic specificity, in vitro and in vivo in 169 independent strains of H. influenzae collected longitudinally over 10 years from adults with chronic obstructive pulmonary disease. Results. The H. influenzae pangenome has 2 alleles of IgA protease genes; all strains have igaA, and 40% of strains have igaB. Each allele has 2 variants with differing proteolytic specificities for human IgA1. A total of 88% of 169 strains express IgA protease activity. Expression of the 4 forms of IgA protease varies among strains. Based on the presence of IgA1 fragments in sputum samples, each of the different forms of IgA protease is selectively expressed in the human airways during infection. Conclusions. Four variants of IgA proteases are variably expressed by H. influenzae during infection of the human airways. PMID:25995193
Murphy, Timothy F; Kirkham, Charmaine; Jones, Megan M; Sethi, Sanjay; Kong, Yong; Pettigrew, Melinda M
Immunoglobulin (Ig)A proteases of Haemophilus influenzae are highly specific endopeptidases that cleave the hinge region of human IgA1 and also mediate invasion and trafficking in human respiratory epithelial cells, facilitating persistence of H. influenzae. Little is known about the expression of IgA proteases in clinical settings of H. influenzae infection. We identified and characterized IgA protease genes in H. influenzae and studied their expression and proteolytic specificity, in vitro and in vivo in 169 independent strains of H. influenzae collected longitudinally over 10 years from adults with chronic obstructive pulmonary disease. The H. influenzae pangenome has 2 alleles of IgA protease genes; all strains have igaA, and 40% of strains have igaB. Each allele has 2 variants with differing proteolytic specificities for human IgA1. A total of 88% of 169 strains express IgA protease activity. Expression of the 4 forms of IgA protease varies among strains. Based on the presence of IgA1 fragments in sputum samples, each of the different forms of IgA protease is selectively expressed in the human airways during infection. Four variants of IgA proteases are variably expressed by H. influenzae during infection of the human airways. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: firstname.lastname@example.org.
IgA nephropathy (IgAN) is characterized by the expansion of the glomerular mesangial matrix with mesangial cell proliferation and/or mononuclear cell infiltration. Glomeruli typically contain generalized diffuse granular mesangial deposits of IgA (mainly galactose-deficient polymeric IgA1), IgG and C3. Electron-dense deposits are observed in the glomerular mesangial area and glomerular basement membrane. Therefore, this disease is considered to be an immune complex-mediated glomerulonephritis. The detailed observations of electron-dense deposits are of value for the evaluation of the disease activity. The evidence- and lumped-system-based histological classification can identify the magnitude of the risk of disease progression and is useful for predicting long-term renal outcome in this disease. A study of IgAN patients showed that the number of angiotensin-II-positive cells was correlated with mast cells containing both tryptase and chymase and containing only tryptase in the interstitial lesions with the most severe pathological changes. Hypercomplementemia occurs in the progression of IgAN and is controlled by an increase of complement regulatory proteins. The measurement of urinary levels of membrane attack complex and factor H and extraglomerular C3 deposition could be useful indicators of renal injury in patients with IgAN. Development of glomerulosclerosis in IgAN patients is associated with podocytopenia and the alteration of the podocyte components, i.e. podocalyxin and dendrin. It appears that the number of urinary podocytes and levels of urinary podocalyxin are useful for predicting histological changes in IgAN patients. A positive correlation was observed between acute extracapillary changes and the number of dendrin-positive nuclei per glomerulus in patients with IgAN. It is concluded that there are many immunopathological predictors of prognosis, including genetic background, in this disease. Thus, the early diagnostic screening of prognosis
Barbour, Sean; Feehally, John
The treatment of IgA nephropathy (IgAN) has been limited by several controversies in the literature, including the benefits of corticosteroids in addition to optimized renin-angiotensin system blockers (RASBs), in those with lower estimated glomerular filtration rate (eGFR), or in different ethnic groups. Recent studies have attempted to address these issues. Two observational studies suggest the efficacy of corticosteroids in those with lower eGFR, but with a higher risk of adverse events. The Supportive versus Immunosuppressive Therapy for the Treatment of Progressive IgA Nephropathy (STOP-IgAN) trial compared immunosuppression with supportive care in addition to optimized RASB, and suggests that corticosteroids (but not cyclophosphamide/azathioprine) may reduce proteinuria but the effect on renal function is not clear, that immunosuppression is associated with a high risk of adverse events and that optimal RASB is very effective at lowering proteinuria and the short-term risk of renal function decline. The Therapeutic Evaluation of Steriods in IgA Nephropathy Global (TESTING) trial compared corticosteroids with placebo in addition to optimized RASB, and demonstrated a decreased risk of renal function decline and lower proteinuria, but a higher risk of adverse events. Additional trials demonstrate the potential efficacy of enteric-budesonide but not rituximab on proteinuria reduction, and conflicting findings with mycophenolate mofetil. Until less toxic therapies for IgAN are available, treatment with corticosteroids will need to be made in the context of conflicting evidence, and should likely be limited to patients at highest risk of disease progression who understand the significant risk of adverse events.
Monia, Kharfi; Aida, Khaled; Amel, Karaa; Ines, Zaraa; Becima, Fazaa; Ridha, Kamoun Mohamed
Background: Linear IgA bullous dermatosis (LAD) of children is relatively frequent in Africa. Aim: We undertook this study to evaluate the frequency of this disease among autoimmune bullous diseases (AIBDs) in Tunisian children. Materials and Methods: We present a 32-year retrospective study (January 1976 to December 2007). Children with chronic acquired bullous diseases seen at the Charles Nicolle Hospital of Tunis and for who direct immunofluorescence (DIF) of the perilesional skin demonstrated linear IgA immunoglobulin deposits were included in the study population. Results: Thirty-one children with LAD were selected representing 65.9% of all AIBDs of children selected in the same period, with a mean age of 5.5 years and a sex ratio (M/F) of 2.4. Most of the children had generalized eruption (28/31), more profuse on the face, pelvic region, buttocks and limbs. Mucosal lesions happened in only four children (12.9%). The mean duration of the disease was 14 months. DIF demonstrated linear IgA deposits along the dermal–epidermal junction in all patients. IgG, IgM, and complement were also seen (20/31). Indirect immunofluorescence was negative in 67% of cases. Eight patients responded to dapsone; however, prednisone had to be added in seven children to control the disease and erythromycin in four others. A long-term remission period was achieved in 76.1% of patients. Conclusion: This study confirms that LAD is the most common AIBD in children in Tunisia which frequently occurs in preschool-aged males. Independently of the used drug, a long-term remission is frequently observed. PMID:21716539
Hart, Felix; Danielczyk, Antje; Goletz, Steffen
IgA antibodies have great potential to improve the functional diversity of current IgG antibody-based cancer immunotherapy options. However, IgA production and purification is not well established, which can at least in part be attributed to the more complex glycosylation as compared to IgG antibodies. IgA antibodies possess up to five N-glycosylation sites within their constant region of the heavy chain as compared to one site for IgG antibodies. The human GlycoExpress expression system was developed to produce biotherapeutics with optimized glycosylation and used here to generate a panel of IgA isotype antibodies directed against targets for solid (TA-mucin 1, Her2, EGFR, Thomsen–Friedenreich) and hematological (CD20) cancer indications. The feasibility of good manufacturing practice was shown by the production of 11 g IgA within 35 days in a one liter perfusion bioreactor, and IgA antibodies in high purity were obtained after purification. The monoclonal IgA antibodies possessed a high sialylation degree, and no non-human glycan structures were detected. Kinetic analysis revealed increased avidity antigen binding for IgA dimers as compared to monomeric antibodies. The IgA antibodies exhibited potent Fab- and Fc-mediated functionalities against cancer cell lines, whereby especially granulocytes are recruited. Therefore, for patients who do not sufficiently benefit from therapeutic IgG antibodies, IgA antibodies may complement current regiment options and represent a promising strategy for cancer immunotherapy. In conclusion, a panel of novel biofunctional IgA antibodies with human glycosylation was successfully generated. PMID:28952521
Khaira, Ambar; Rathi, Om P; Mahajan, Sandeep; Sharma, Alok; Dinda, Amit K; Tiwari, Suresh C
A 14-year-old girl presented with a 10-year history of a large crusted plaque over the right thigh for 10 years and small reddish plaque over the left upper back for 3 months. On routine evaluation, she was found to have hematuria. Skin biopsy from the lesion was suggestive of skin tuberculosis (lupus vulgaris), and kidney biopsy showed features of IgA nephropathy (IgAN). Fine-needle aspiration from the inguinal lymph node was consistent with granulomatous disease. The patient has been on anti-tubercular treatment, and the hematuria has subsided.
Singh, P; Khaira, A; Sharma, A; Dinda, A K; Tiwari, S C
A 34-year-old man presented with polymerase chain reaction-positive pleuropulmonary tuberculosis with asymptomatic subnephrotic proteinuria and microscopic haematuria. He was diagnosed to have IgA nephropathy on renal biopsy. The patient was started on a four-drug anti-tuberculous therapy. Healing of the pleuropulmonary lesions along with disappearance of proteinuria and haematuria were seen both at one month and six months post-treatment, with no relapse of renal symptoms at one-year follow-up.
Atak, Apurva; Mukherjee, Shuvolina; Jain, Rekha; Gupta, Shabarni; Singh, Vedita Anand; Gahoi, Nikita; K P, Manubhai; Srivastava, Sanjeeva
The discovery of DNA microarrays was a major milestone in genomics; however, it could not adequately predict the structure or dynamics of underlying protein entities, which are the ultimate effector molecules in a cell. Protein microarrays allow simultaneous study of thousands of proteins/peptides, and various advancements in array technologies have made this platform suitable for several diagnostic and functional studies. Antibody arrays enable researchers to quantify the abundance of target proteins in biological fluids and assess PTMs by using the antibodies. Protein microarrays have been used to assess protein-protein interactions, protein-ligand interactions, and autoantibody profiling in various disease conditions. Here, we summarize different microarray platforms with focus on its biological and clinical applications in autoantibody profiling and PTM studies. We also enumerate the potential of tissue microarrays to validate findings from protein arrays as well as other approaches, highlighting their significance in proteomics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Markina, O A; Iastrebova, N E; Vaneeva, N P; Volkov, I K; Katosova, L K
124 sera of children with chronic bronchitis, chronic pneumonia, bronchial asthma, exogenic allergic alveolitis, congenital developmental defects of the lungs and the syndrome of the situs inversus of organs were examined with a view to study the state of humoral immunity to tissues. The study was carried out by means of the enzyme-linked immunosorbent assay with the use of collagen, elastin, DNA (native and denaturated), membrane antigens of the lung, the liver, the small intestine and the large intestine. Among all groups of patients autoimmune disturbances, manifested by a rise in the level of autoantibodies of different specificity, were registered. The degree of manifestation of autoimmune disturbances depended on the kind of pathology. After treatment a decrease in the level of autoantibodies was registered in the examinees.
Meager, Anthony; Visvalingam, Kumuthini; Peterson, Pärt; Möll, Kaidi; Murumägi, Astrid; Krohn, Kai; Eskelin, Petra; Perheentupa, Jaakko; Husebye, Eystein; Kadota, Yoshihisa; Willcox, Nick
Background The autoimmune regulator (AIRE) gene influences thymic self-tolerance induction. In autoimmune polyendocrinopathy syndrome type 1 (APS1; OMIM 240300), recessive AIRE mutations lead to autoimmunity targetting endocrine and other epithelial tissues, although chronic candidiasis usually appears first. Autoimmunity and chronic candidiasis can associate with thymomas as well. Patients with these tumours frequently also have high titre immunoglobulin G autoantibodies neutralising type I interferon (IFN)–α and IFN-ω, which are secreted signalling proteins of the cytokine superfamily involved in both innate and adaptive immunity. Methods and Findings We tested for serum autoantibodies to type I IFNs and other immunoregulatory cytokines using specific binding and neutralisation assays. Unexpectedly, in 60/60 Finnish and 16/16 Norwegian APS1 patients with both AIRE alleles mutated, we found high titre neutralising immunoglobulin G autoantibodies to most IFN-α subtypes and especially IFN-ω (60% homologous to IFN-α)—mostly in the earliest samples. We found lower titres against IFN-β (30% homologous to IFN-α) in 23% of patients; two-thirds of these (from Finland only) also had low titres against the distantly related “type III IFN” (IFN-λ1; alias interleukin-29). However, autoantibodies to the unrelated type II IFN, IFN-γ, and other immunoregulatory cytokines, such as interleukin-10 and interleukin-12, were much rarer and did not neutralise. Neutralising titres against type I IFNs averaged even higher in patients with APS1 than in patients with thymomas. Anti–type I IFN autoantibodies preceded overt candidiasis (and several of the autoimmune disorders) in the informative patients, and persisted for decades thereafter. They were undetectable in unaffected heterozygous relatives of APS1 probands (except for low titres against IFN-λ1), in APS2 patients, and in isolated cases of the endocrine diseases most typical of APS1, so they appear to be APS1
Sack, U; Conrad, K; Csernok, E; Frank, I; Hiepe, F; Krieger, T; Kromminga, A; Landenberg, P von; Messer, G; Witte, T; Mierau, R
Systemic autoimmune diseases are characterized by the presence of antinuclear autoantibodies (ANA). Diluted patient sera are typically used to screen for the presence of ANA by immunfluorescence microscopy with fixed HEp-2 cells. Despite high-quality test kits, reports of different laboratories frequently present controversial results. This article recommends unified processing and interpretation of HEp-2 based screening for autoantibodies. Suggestions are made for the selection of high-quality test kits, optimized processing and diagnostic procedures. In addition to a relevant clinical diagnosis and an experienced laboratory specialist, the following procedure is highly recommended to achieve good laboratory practice: Initial HEp-2 based screening by indirect immunofluorescence, starting with a 1:80 serum dilution, and evaluation in a bright fluorescence microscope, pathological values from a titer of 1:160 upwards, internal quality checks and unified interpretation. We aim to improve diagnosis and care of patients with autoimmune diseases as a central focus of the European Autoimmunity Standardization Initiative (EASI).
Lu, H; Califano, J V; Schenkein, H A; Tew, J G
The aims of this study were to determine the immunodominant antigens of Actinobacillus actinomycetemcomitans serotype b (Aab) for the different immunoglobulin (Ig) classes and subclasses and to determine the relative levels of these different Igs in serum. Seropositive early-onset periodontitis patients were sampled, and the Ig classes IgG, IgA, and IgM and subclasses IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2 were studied. Reactivity with Aab antigens was assessed by using the Western blot (immunoblot) in limiting dilution analysis and radioimmunoassay with sera from 13 early-onset periodontitis subjects. A smeared antigen in the upper portion of the immunoblots, typical of high-molecular-weight LPS, was immunodominant for IgG, IgA, IgM, IgG1, IgG2, IgG3, IgA1, and IgA2. This smeared antigen was present in every patient for all of these Igs at the endpoint. A few additional antigens were also present at the endpoint in some patients, but none were present in more than half of the subjects. The distribution of antibody titers by Ig classes reactive with the Aab immunodominant antigen was IgG > IgA > IgM. The distribution of antibody titers by IgG subclass was IgG2 > IgG1 approximately IgG3. Further quantitation by radioimmunoassay revealed that the mean concentration of IgG2 (65.7 micrograms/ml) was significantly greater than that of IgG1 (8.8 micrograms/ml). The IgA subclass distribution was IgA1 >> IgA2, with IgA1 apparently being second only to IgG2. Therefore, the Aab antigen eliciting the highest antibody level in virtually all Ig classes and subclasses appeared to be lipopolysaccharide, and IgG2 was markedly elevated over all other serum Ig classes or subclasses reactive with Aab. Images PMID:8500879
Sosenko, Jay M; Skyler, Jay S; Palmer, Jerry P; Krischer, Jeffrey P; Yu, Liping; Mahon, Jeffrey; Beam, Craig A; Boulware, David C; Rafkin, Lisa; Schatz, Desmond; Eisenbarth, George
We assessed whether a risk score that incorporates levels of multiple islet autoantibodies could enhance the prediction of type 1 diabetes (T1D). TrialNet Natural History Study participants (n = 784) were tested for three autoantibodies (GADA, IA-2A, and mIAA) at their initial screening. Samples from those positive for at least one autoantibody were subsequently tested for ICA and ZnT8A. An autoantibody risk score (ABRS) was developed from a proportional hazards model that combined autoantibody levels from each autoantibody along with their designations of positivity and negativity. The ABRS was strongly predictive of T1D (hazard ratio [with 95% CI] 2.72 [2.23-3.31], P < 0.001). Receiver operating characteristic curve areas (with 95% CI) for the ABRS revealed good predictability (0.84 [0.78-0.90] at 2 years, 0.81 [0.74-0.89] at 3 years, P < 0.001 for both). The composite of levels from the five autoantibodies was predictive of T1D before and after an adjustment for the positivity or negativity of autoantibodies (P < 0.001). The findings were almost identical when ICA was excluded from the risk score model. The combination of the ABRS and the previously validated Diabetes Prevention Trial-Type 1 Risk Score (DPTRS) predicted T1D more accurately (0.93 [0.88-0.98] at 2 years, 0.91 [0.83-0.99] at 3 years) than either the DPTRS or the ABRS alone (P ≤ 0.01 for all comparisons). These findings show the importance of considering autoantibody levels in assessing the risk of T1D. Moreover, levels of multiple autoantibodies can be incorporated into an ABRS that accurately predicts T1D.
Deroux, Alban; Dumestre-Perard, Chantal; Dunand-Faure, Camille; Bouillet, Laurence; Hoffmann, Pascale
On average, 10 % of infertile couples have unexplained infertility. Auto-immune disease (systemic lupus erythematosus, anti-phospholipid syndrome) accounts for a part of these cases. In the last 20 years, aspecific auto-immunity, defined as positivity of auto-antibodies in blood sample without clinical or biological criteria for defined diseases, has been evoked in a subpopulation of infertile women. A systematic review was performed (PUBMED) using the MESH search terms "infertility" and "auto-immunity" or "reproductive technique" or "assisted reproduction" or "in vitro fertilization" and "auto-immunity." We retained clinical and physiopathological studies that were applicable to the clinician in assuming joint management of both infertility associated with serum auto-antibodies in women. Thyroid auto-immunity which affects thyroid function could be a cause of infertility; even in euthyroidia, the presence of anti-thyroperoxydase antibodies and/or thyroglobulin are related to infertility. The presence of anti-phospholipid (APL) and/or anti-nuclear (ANA) antibodies seems to be more frequent in the population of infertile women; serum auto-antibodies are associated with early ovarian failure, itself responsible for fertility disorders. However, there exist few publications on this topic. The methods of dosage, as well as the clinical criteria of unexplained infertility deserve to be standardized to allow a precise response to the question of the role of serum auto-antibodies in these women. The direct pathogenesis of this auto-immunity is unknown, but therapeutic immunomodulators, prescribed on a case-by-case basis, could favor pregnancy even in cases of unexplained primary or secondary infertility.
Reimand, K; Talja, I; Metsküla, K; Kadastik, U; Matt, K; Uibo, R
The aim of this study was to investigate the prevalence and character of autoimmune derangements in women with reproductive failure. A total of 108 females (age range 17-43, mean 27.5 years), including 16 with primary menstrual cycle disturbances and polycystic ovaries (PCO), 20 with polycystic ovary syndrome (PCOS), 38 with endometriosis (E), and 34 with chronic anovulation, luteal phase insufficiency, subfertility or unexplained infertility (INF) were investigated. A control group of 392 women was formed from an unselected population sample (age range 17-43, mean 31.0 years). All sera were tested by indirect immunofluorescence method to assess common autoantibodies: nuclear (ANA), smooth muscle (SMA), parietal cell (PCA), thyroid microsomal (TMA), reticulin (ARA), mitochondrial (AMA) and liver/kidney microsomal autoantibodies (LKMA). Enzyme-linked immunosorbent assay was used to detect antibodies against beta2-glycoprotein I (anti-beta 2GPI) and carbonic anhydrase (anti-CA). Our results showed that 40.7% of patients' sera and 14.8% of control sera contained one or more common autoantibodies, ANA and SMA were most frequently detected (difference between two groups P<0.005). Anti-beta 2GPI were found in eight cases (7.4%), including two patients with INF but without other autoantibodies. Anti-CA were revealed in nine cases (8.3%) including patients' PCOS, E and INF. A comparison of patients' clinical data with antibody assay results did not reveal any significant associations. Our results indicate a high prevalence of autoimmune reactions in women with reproductive failure due to the most common causes PCO, PCOS and E as well as in unexplained infertility. This might reflect the propensity to develop autoimmune reactions in such patients, including pathogenic autoimmune reactions to specific target antigens.
Defendenti, Caterina; Atzeni, Fabiola; Spina, Maria Francesca; Grosso, Silvia; Cereda, Aldo; Guercilena, Giacinto; Bollani, Simona; Saibeni, Simone; Puttini, Piercarlo Sarzi
Anti-Ro/SSA antibodies, which were described for the first time in systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS), are the most prevalent extractable nuclear antigen (ENA) specificity identified in laboratories. Two types of anti-Ro/SSA antibodies have been described, anti-SSA-52 kDa (aSSA52) and anti-SSA-60 kDa (aSSA60), each specific to different antigens. Anti-Ro/SSA52 autoantibodies are more frequent than other autoantibodies possibly because of the antigen's accessible and ubiquitous nature. The sites involved and the symptoms associated with these autoantibodies depend on the antigen's structural variability. Isolated congenital complete atrioventricular block (CAVB) shows a close association with maternal anti-Ro/SSA and anti-La/SSB antibodies; the highest relative risks of CAVB are seen in offspring of mothers with antibodies against 52-kDa Ro and 48-kDa La proteins. Anti-Ro/SSA52 antibodies have little impact on adult rheumatic autoimmune diseases or adult cardiac arrhythmias, but the course of autoimmune liver diseases is greatly worsened by their presence, and solid tumours tend to relapse. Their diagnostic role in rheumatic diseases is controversial, although a significant association between isolated anti-Ro/SSA52-kDa positivity and myositis and to a lesser extent with systemic sclerosis (SSc) has been described. However, the majority of the specific diagnosis is mostly based on the simultaneous presence of other autoantibodies that seems diagnostically more relevant.
Feghali-Bostwick, Carol A.; Gadgil, Aneal S.; Otterbein, Leo E.; Pilewski, Joseph M.; Stoner, Michael W.; Csizmadia, Eva; Zhang, Yingze; Sciurba, Frank C.; Duncan, Steven R.
Rationale: Adaptive immune responses are present in patients with chronic obstructive pulmonary disease (COPD), and it has been postulated that these processes could be autoreactive. Objectives: To ascertain if humoral autoimmunity could play a role in COPD pathogenesis. Methods: Circulating IgG autoantibodies were detected by immunofluorescence and immunoprecipitation. Immunohistochemistry and immunofluorescence were used to evaluate intrapulmonary IgG and complement (C3) deposition in human lung explants. Autoantibody pathogenicity was also investigated with an antibody-dependent cell-mediated cytotoxicity assay. Measurements and Main Results: The prevalence of anti–HEp-2 epithelial cell autoantibodies in 47 smokers/former smokers with COPD (GOLD stages 1–4) was greater than among 8 subjects with a smoking history but normal spirometry and 21 healthy control subjects who had never smoked (68 vs. 13 vs. 10%, respectively; P < 0.0001). Antibodies against primary pulmonary epithelial cells were found in 12 of 12 patients with COPD versus 3 of 12 never-smoked control subjects (P < 0.001). Self-antigens immunoprecipitated from 34 of 35 (97%) of COPD plasmas (vs. 0/12 never-smoked controls). Antibodies against a particular 130-kD autoantigen (n = 7) were associated with decreased body mass index (23.2 ± 2.1 vs. 29.5 ± 1.0 kg/m2, P = 0.007). Intrapulmonary immune complexes were present in six of six and C3 was seen in five of six COPD lung explants, unlike zero of six and one of six normals, respectively. Cytotoxicity of pulmonary epithelial cells by allogeneic mononuclear cells also increased 46% after incubation with COPD plasmas (n = 10), compared with identical treatments with eight normal specimens (P = 0.03). Conclusions: IgG autoantibodies with avidity for pulmonary epithelium, and the potential to mediate cytotoxicity, are prevalent in patients with COPD. Autoreactive adaptive immune responses may be important in the etiology of this disease. PMID:17975205
Feghali-Bostwick, Carol A; Gadgil, Aneal S; Otterbein, Leo E; Pilewski, Joseph M; Stoner, Michael W; Csizmadia, Eva; Zhang, Yingze; Sciurba, Frank C; Duncan, Steven R
Adaptive immune responses are present in patients with chronic obstructive pulmonary disease (COPD), and it has been postulated that these processes could be autoreactive. To ascertain if humoral autoimmunity could play a role in COPD pathogenesis. Circulating IgG autoantibodies were detected by immunofluorescence and immunoprecipitation. Immunohistochemistry and immunofluorescence were used to evaluate intrapulmonary IgG and complement (C3) deposition in human lung explants. Autoantibody pathogenicity was also investigated with an antibody-dependent cell-mediated cytotoxicity assay. The prevalence of anti-HEp-2 epithelial cell autoantibodies in 47 smokers/former smokers with COPD (GOLD stages 1-4) was greater than among 8 subjects with a smoking history but normal spirometry and 21 healthy control subjects who had never smoked (68 vs. 13 vs. 10%, respectively; P < 0.0001). Antibodies against primary pulmonary epithelial cells were found in 12 of 12 patients with COPD versus 3 of 12 never-smoked control subjects (P < 0.001). Self-antigens immunoprecipitated from 34 of 35 (97%) of COPD plasmas (vs. 0/12 never-smoked controls). Antibodies against a particular 130-kD autoantigen (n = 7) were associated with decreased body mass index (23.2 +/- 2.1 vs. 29.5 +/- 1.0 kg/m(2), P = 0.007). Intrapulmonary immune complexes were present in six of six and C3 was seen in five of six COPD lung explants, unlike zero of six and one of six normals, respectively. Cytotoxicity of pulmonary epithelial cells by allogeneic mononuclear cells also increased 46% after incubation with COPD plasmas (n = 10), compared with identical treatments with eight normal specimens (P = 0.03). IgG autoantibodies with avidity for pulmonary epithelium, and the potential to mediate cytotoxicity, are prevalent in patients with COPD. Autoreactive adaptive immune responses may be important in the etiology of this disease.
Hanly, J. G.; Urowitz, M. B.; Siannis, F.; Farewell, V.; Gordon, C.; Bae, S.C.; Isenberg, D.; Dooley, M.A.; Clarke, A.; Bernatsky, S.; Gladman, D.; Fortin, P.R.; Manzi, S.; Steinsson, K.; Bruce, I.; Ginzler, E.; Aranow, C.; Wallace, D.J.; Ramsey-Goldman, R.; Van Vollenhoven, R.; Sturfelt, G.; Nived, O.; Sanchez-Guerrero, J.; Alarcón, G.S.; Petri, M.; Khamashta, M.; Zoma, A.; Kalunian, K.; Douglas, J.; Qi, Qiufen; Merrill, J. T.
Objective To examine the association between neuropsychiatric (NP) events with antiphospholipid antibodies (lupus anticoagulant, anticardiolipin), anti-β2 glycoprotein-I, anti-ribosomal P and anti-NR2 glutamate receptor antibodies in an international inception cohort. Methods NP events were identified using the ACR case definitions and clustered into central/peripheral and diffuse/focal events. Attribution of NP events was determined using decision rules of different stringency (model A and model B). Autoantibodies were measured without knowledge of NP events or their attribution. Results 412 patients (87.3% female; mean (± SD) age of 34.9 ± 13.5 years; mean disease duration 5.0 ± 4.2 months) were studied. There were 214 NP events in 133 (32.3%) patients. NP events attributed to SLE varied from 15% (model A) to 36% (model B). There was no association between autoantibodies and NP events from all causes. However the frequency of anti-ribosomal P antibodies in patients with NP events due to SLE (model A) was 4/24 (16.6%) compared to 3/109 (2.8%) for all other NP events and 24/279 (8.6%) with no NP events (P=0.07). Furthermore anti-ribosomal P antibodies in patients with central NP events attributed to SLE (model A) was 4/20 (20%) vs. 3/107 (2.8%) for other NP events and 24/279 (8.6%) with no NP events (P = 0.04). For diffuse NP events the antibody frequencies were 3/11 (27%) compared to 4/111 (3.6%) and 24/279 (8.6%) respectively (P=0.02). Conclusion NP events at onset of SLE were associated with anti-ribosomal P antibodies, suggesting a pathogenetic role for this autoantibody. There was no association with other autoantibodies. PMID:18311802
Hirose, Misa; Vafia, Katerina; Kalies, Kathrin; Groth, Stephanie; Westermann, Jürgen; Zillikens, Detlef; Ludwig, Ralf J; Collin, Mattias; Schmidt, Enno
Autoantibody-mediated diseases comprise a heterogeneous group of disorders in which the pathogenic potential of autoantibodies has been clearly demonstrated. In general, their treatment relies on the long-term use of systemic corticosteroids and other immunosuppressants that are associated with considerable adverse reactions. EndoS, an endoglycosidase derived from Streptococcus pyogenes, specifically hydrolyzes the N-linked glycan of native IgG and has previously been shown to modulate the interaction between the Fc portion of autoantibody and Fcγ receptors on leukocytes. Here, different models of autoimmunity to type VII collagen, a structural protein of the dermal-epidermal junction (DEJ), were employed to explore the therapeutic potential of EndoS. First, pretreatment of otherwise pathogenic anti-murine type VII collagen (mCOL7) IgG with EndoS significantly reduced split formation at the DEJ in cryosections of murine skin and abrogated clinical disease in mice. Next, the effect of EndoS was also seen when the enzyme was injected into mice after pathogenic anti-mCOL7 IgG had been administered. Finally, to mimic the patient situation even closer, EndoS was applied in mice that had already developed clinical disease after immunization with mCOL7. In all EndoS-treated mice, disease progression was stopped, and in the majority of mice, clinical disease even regressed. Of note, EndoS was shown to hydrolyze already in vivo-bound pathogenic autoantibodies. In addition, EndoS treatment decreased lesional expression of activating FcγRs while increasing FcγRIIB expression. Copyright © 2012 Elsevier Ltd. All rights reserved.
Quaio, Caio R D C; Carvalho, Jozélio F; da Silva, Clovis A; Bueno, Cleonice; Brasil, Amanda S; Pereira, Alexandre C; Jorge, Alexander A L; Malaquias, Alexsandra C; Kim, Chong A; Bertola, Débora R
The association of RASopathies [Noonan syndrome (NS) and Noonan-related syndromes] and autoimmune disorders has been reported sporadically. However, a concomitant evaluation of autoimmune diseases and an assessment of multiple autoantibodies in a large population of patients with molecularly confirmed RASopathy have not been performed. The clinical and laboratory features were analyzed in 42 RASopathy patients, the majority of whom had NS and five individuals had Noonan-related disorders. The following autoantibodies were measured: Anti-nuclear antibodies, anti-double stranded DNA, anti-SS-A/Ro, anti-SS-B/La, anti-Sm, anti-RNP, anti-Scl-70, anti-Jo-1, anti-ribosomal P, IgG and IgM anticardiolipin (aCL), thyroid, anti-smooth muscle, anti-endomysial (AE), anti-liver cytosolic protein type 1 (LC1), anti-parietal cell (APC), anti-mitochondrial (AM) antibodies, anti-liver-kidney microsome type 1 antibodies (LKM-1), and lupus anticoagulant. Six patients (14%) fulfilled the clinical criteria for autoimmune diseases [systemic lupus erythematous, polyendocrinopathy (autoimmune thyroiditis and celiac disease), primary antiphospholipid syndrome (PAPS), autoimmune hepatitis, vitiligo, and autoimmune thyroiditis]. Autoimmune antibodies were observed in 52% of the patients. Remarkably, three (7%) of the patients had specific gastrointestinal and liver autoantibodies without clinical findings. Autoimmune diseases and autoantibodies were frequently present in patients with RASopathies. Until a final conclusion of the real incidence of autoimmunity in Rasopathy is drawn, the physicians should be alerted to the possibility of this association and the need for a fast diagnosis, proper referral to a specialist and ultimately, adequate treatment.
Giil, Lasse M; Kristoffersen, Einar K; Vedeler, Christian A; Aarsland, Dag; Nordrehaug, Jan Erik; Winblad, Bengt; Cedazo-Minguez, Angel; Lund, Anders; Reksten, Tove Ragna
Autoantibodies with agonist function are described in cardiovascular disorders. Since vascular risk factors are associated with an increased risk for Alzheimer's disease (AD), we investigated a potential association between antibodies to the angiotensin 2 type 1 receptor (anti-AT1R) and AD. The primary objective of this study was to investigate the association between anti-AT1R and AD. The secondary objective was to investigate the association between clinical or biomarker features of AD and anti-AT1R. Samples from patients with mild AD participating in a longitudinal study in Western Norway (n = 92, 65 [71%] females, mean age 74.8 [range 50-89]) and age- and gender-matched healthy controls (n = 102) were included. Cerebrospinal fluid (CSF) AD biomarkers were assessed in a subgroup of patients. Patients were examined annually, including Mini-Mental State Examination. ELISA was used to measure anti-AT1R in serum. Non-parametric tests were used for statistical calculations and a p < 0.05 was considered significant. AD patients had significantly higher levels of anti-AT1R compared with healthy controls (10.2 U/mL versus 8.1 U/mL, p = 0.04). This difference was found only in patients without hypertension and diabetes. Anti-AT1R levels correlated with CSF total tau (p = 0.03) and phosphorylated tau (p = 0.03) levels, and inversely with blood pressure in AD (Spearman R -0.277, p = 0.008). AD is associated with increased levels of anti-AT1R, and the antibodies correlated with CSF total, and phosphorylated tau levels. Further research is needed to understand the blood pressure response in AD without hypertension and a potential link between tau and anti-AT1R in AD.
Zumberg, M S; Procter, J L; Lottenberg, R; Kitchens, C S; Klein, H G
Alloimmunization to erythrocyte antigens is a well-characterized complication in heavily transfused patients. Less well recognized, however, is the frequency of autoantibody formation in these previously alloimmunized patients. The autoantibodies are heterogeneous and of variable clinical significance. We describe the clinical history, laboratory evaluation, diagnosis, and treatment in 4 patients who developed autoantibodies in temporal association with alloantibody formation. In one case, the autoantibody found on routine screening had no clinical significance. In another case, the autoantibody made accurate blood typing and subsequent transfusion exceedingly difficult. Two patients experienced hemolysis as a consequence of the autoantibody. The management of both patients included supportive measures, while one patient required glucocorticosteroids and red blood cell transfusion. We review the published literature concerning autoimmunization in the transfused alloimmunized host. The spectrum of clinical consequences is important for the general practitioner to recognize, as these complications may occur during routine blood transfusions.
Barderas, Rodrigo; Villar-Vázquez, Roi; Fernández-Aceñero, María Jesús; Babel, Ingrid; Peláez-García, Alberto; Torres, Sofía; Casal, J Ignacio
Although autoantibody detection has been proposed for diagnosis of colorectal cancer, little is known about their initial production and development correlation with cancer progression. Azoxymethane/dextran sodium sulfate (AOM/DSS)-treated mice developed colon adenocarcinoma in the distal colon similar to human sporadic colon cancer. We assessed this model together with AOM and DSS-only models for their applicability to early detection of cancer. All AOM/DSS-treated mice produced autoantibodies to tumor-associated antigens analogous to those observed in human colon cancer patients. Autoantibody response was related to tumor antigen overexpression. Cancer autoantibodies were detected 21 days after starting treatment, when no malignant histopathological features were detectable, and they increased according to tumor progression. When carcinogenesis was induced separately by AOM or DSS, only those mice that developed malignant lesions produced significant levels of autoantibodies. These findings demonstrate that autoantibody development is an early event in tumorigenesis and validates its use for preclinical colon cancer diagnosis.
Himoto, Takashi; Masaki, Tsutomu
Patients with chronic hepatitis C virus (HCV) infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren's syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.