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Purpose: To evaluate the clinical and genetic characteristics of 3 children with Haploinsufficiency of A20 (HA20)., Methods: The clinical and genetic testing data of 3 children with HA20 treated at Capital Institute of Pediatrics (CIP) between August 2016 and October 2019 were retrospectively analysed., Result: Patient 1 presented with arthritis and inflammatory bowel disease, patient 2 presented with axial spinal arthritis and lupus-like syndrome, and patient 3 presented with recurrent oral ulcers, gastrointestinal ulcers, and perianal abscesses. Regarding laboratory tests, patients were found to have elevated white blood cell (WBC) count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The CRP and ESR was reported to be high in all the patients. The WBC was reported to be high in patient 1 and 3. Patient 2 was positive for antinuclear antibodies, anti-Sjögren's syndrome antigen A, dsDNA, rheumatoid factor and Coombs test. Genetic testing showed that all three patients had heterozygous mutation in TNFAIP3 gene. As for the treatment, patient 1 was treated with TNFα antagonist, patient 2 was treated with TNF α antagonist and sulfasalazine, and patient 3 was treated with corticosteroids and thalidomide. Patients 1 and 2 were followed for four and 3 months, respectively. There was an improvement in joint and gastrointestinal symptoms; inflammatory indices and rheumatoid factor (RF) were normal, and dsDNA and Coombs test became negative. Patient 3 was treated at another hospital and showed gradual improvement in oral ulcers and perianal abscesses., Conclusion: HA20 is a single-gene auto-inflammatory disease caused by mutation in tumour necrosis factor (TNF)-α-induced protein 3 (TNFAIP3) gene. It may present as Behçet-like syndrome and resemble various other autoimmune diseases as well. Corticosteroids and immunosuppressive agents are effective treatments, and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing should be proactively performed for children with early-age onset or Behçet-like syndrome to achieve early diagnosis and accurate treatment.

IgG oligoclonal bands (OCBs) are present in the cerebrospinal fluid (CSF) of more than 95% of patients with multiple sclerosis (MS), and are considered to be the immunological hallmark of disease. However, the target specificities of the IgG in MS OCBs have remained undiscovered. Nevertheless, evidence that OCBs are associated with increased levels of disease activity and disability support their probable pathological role in MS. We investigated the antigen specificity of individual MS CSF IgG from 20 OCB-positive patients and identified 40 unique peptides by panning phage-displayed random peptide libraries. Utilizing our unique techniques of phage-mediated real-time Immuno-PCR and phage-probed isoelectric focusing immunoblots, we demonstrated that these peptides were targeted by intrathecal oligoclonal IgG antibodies of IgG1 and IgG3 subclasses. In addition, we showed that these peptides represent epitopes sharing sequence homologies with proteins of viral origin, and proteins involved in cell stress, apoptosis, and inflammatory processes. Although homologous peptides were found within individual patients, no shared peptide sequences were found among any of the 42 MS and 13 inflammatory CSF control specimens. The distinct sets of oligoclonal IgG-reactive peptides identified by individual MS CSF suggest that the elevated intrathecal antibodies may target patient-specific antigens., Competing Interests: The authors have declared that no competing interests exist.

Background: Autologous hematological stem cell transplantation (HSCT) is a novel therapy for systemic sclerosis (SSc) that has been validated in three randomized controlled trials., Objectives: To report the first Israeli experience with HSCT for progressive SSc and review the current literature., Methods: Five SSc patients who were evaluated in our department and were treated by HSCT were included. Medical records were evaluated retrospectively. Demographic, clinical, and laboratory data were recorded. Continuous data are presented as the mean ± standard deviation. Categorical variables are presented as frequencies and percentages., Results: Five SSc patients were treated with HSCT. Four patients were adults (mean age 53 ± 12 years) and one was a 12-year-old pediatric patient. All patients were female. HSCT was initiated 1.4 ± 0.8 years after diagnosis. Two patients were RNA POLIII positive, two were anti-topoisomerase 1 positive, and one only antinuclear antibodies positive. All patients had skin and lung involvement. The mean modified Rodnan Skin Score was 29 ± 4.7 before HSCT, which improved to 10.4 ± 9.6 after HSCT. The forced vital capacity improved from 68 ± 13% to 90 ± 28%. Diffusing capacity of the lungs for carbon monoxide increased by 6%. Among severe adverse events were cyclophosphamide-related congestive heart failure, antithymocyte globulin-related capillary leak syndrome, and scleroderma renal crisis. All symptoms completely resolved with treatment without sequela. No treatment related mortality was recorded., Conclusions: HSCT is an important step in the treatment of progressive SSc in Israel. Careful patient selection reduces treatment related morbidity and mortality.

Objectives: The aim of our study is to clarify the association of myositis-specific autoantibodies (MSAs) with clinical and laboratory features in Japanese patients with juvenile idiopathic inflammatory myopathies (JIIMs)., Methods: We retrospectively analyzed the frequency of MSAs and their association with clinical or laboratory findings in 25 Japanese patients with JIIMs in Hokkaido district., Results: Eighteen of the 25 patients (72%) were positive for MSAs; seven with anti-melanoma differentiation associated gene (MDA) 5 (28%), five with anti-transcriptional intermediary factor (TIF)-1γ (20%), four with anti-MJ/nuclear matrix protein (NXP)-2 (16%), two with anti-Jo-1 (8%), one with anti- HMG-CoA reductase, one with anti-signal recognition peptide (SRP) antibodies (4% each), including co-existence and transition of MSAs in one patient each. Anti-MDA5 antibodies were related to interstitial lung disease (ILD) and arthritis but not to amyopathic juvenile dermatomyositis. Drug-free remission was achieved, once ILD was overcome in this group. Anti-TIF-1γ antibodies were associated with typical rashes and mild myositis. Anti-MJ/NXP2 and anti-SRP antibodies were associated with severe muscle weakness. No patient was complicated with malignancy., Conclusion: Anti-MDA5 antibodies are prevalent and closely associated with ILD in our series compared with other countries. There was no apparent difference in clinical features associated with other MSAs among races.

Introduction: Autoimmune hepatitis (AIH) is a cause of chronic liver disease. It is usually suspected based on clinical presentation and laboratory findings, but the diagnosis relies on the presence of specific autoantibodies and characteristic histology. Other unexplained findings should always prompt investigation for coexisting syndromes., Case Presentation: The patient is a 60-year-old Hispanic female with a history of mild asthma presented with exertional and pleuritic chest pain with weight loss, arthralgia, subjective fever, and night sweats for the last 3 months. Given the nonspecific nature of the presentation, further workup was pursued. Laboratory results indicated pancytopenia, elevated INR, and positive autoimmune panel including ANA, anti-chromatin, anti-histone, and rheumatoid factor as well as abnormal C3 and C4. Subsequent liver biopsy with interface hepatitis lead to a diagnosis of AIH with concurrent systemic lupus erythematosus suspected., Conclusion: The diagnostic work up for AIH is multimodal and aims to differentiate other etiologies such as congestive hepatopathy, iron overload, viral hepatitis, and other autoimmune liver diseases. In this particular case, unusual clinical and laboratory findings led to diagnosis of the overlap syndrome. Treatment for both was necessary to prevent further progression of disease.

Laboratory tests are useful in diagnosing rheumatic diseases, but clinicians should be aware of the limitations of these tests. This article uses case vignettes to provide practical and evidence-based guidance on requesting and interpreting selected tests, including rheumatoid factor, anticitrullinated peptide antibody, antinuclear antibody, antiphospholipid antibodies, antineutrophil cytoplasmic antibody, and human leukocyte antigen-B27., (Copyright © 2019 Cleveland Clinic.)

Objectives: The purpose of this study is to clarify associations between maternal clinical features and adverse pregnancy outcomes (APOs) in mothers with connective tissue diseases (CTDs)., Methods: We retrospectively examined maternal clinical features including backgrounds, autoantibodies, CTD flare-ups, and therapies during pregnancies as well as fetal outcomes in 90 pregnancies (66 mothers) at our hospital from January 2006 to September 2016., Results: Underlying CTDs were SLE (N = 41), MCTD (N = 10), RA (N = 15), SS (N = 10), and others (N = 14). Anti-SS-A antibody was detected in 60.3%, lupus anticoagulant (LAC) was in 11.4%, and anti-cardiolipin-β2glycoprotein1 antibody was in 18.5%. Flare-ups of CTDs occurred in 20 pregnancies (22.2%). Corticosteroids (CS) was administered in 73 pregnancies, immunosuppressants in four, and biologics in one. Among the 85 pregnancies other than five early abortions within 12 weeks of gestational age, 33 cases had APOs while the remaining 52 cases were normal. Although disease duration, MCTD, high dose of CS, flare-ups of CTDs, and positive LAC significantly correlated with APOs by univariate analysis, only MCTD was a significant independent predictor for APOs by multivariate analysis., Conclusion: Disease duration, MCTD, high dose of CS, flare-ups of CTDs, and LAC might be possible predictive risk factors for APOs in pregnancies with CTDs. Of these, MCTD was a significant independent risk factor.

Myositis-specific (MSAs) or-associated autoantibodies (MAAs) have been linked to particular clinical phenotypes of idiopathic inflammatory myopathies (IIM) and appear to aid diagnosis. The objective of this study was to analyze the prevalence of MSAs and MAAs and their possible clinical associations in Greek IIM patients. This study comprised 95 IIM patients classified based on the 2017 EULAR/ACR classification criteria. All patients had MSAs and MAAs measured in their sera by line immunoblot assay. Dermatomyositis was the most prevalent IIM clinical subtype. MSAs were found in 44% of the patients, whereas MAAs in 23%. The most frequently detected MSA was anti-Jo-1 (22%), while the most frequently detected MAA was anti-Ro-52 (30%). The distributions of MSAs/MAAs did not differ between the five IIM subgroups, except for anti-Mi-2 which was only detected in dermatomyositis patients. Patients with at least one MSA and/or MAA positivity showed more frequently IIM characteristic skin rashes, while those presenting solely MAA positivity had more often puffy hands and Raynaud's phenomenon. Anti-Jo1-positive patients presented more frequently lung disease, while anti-Ro52 positivity related to mechanic's hands. Anti-Ro-52 and anti-Jo-1 strongly associated with one another. Prevalence of IIM subtypes and of MSAs/MAAs in our patients is in line with published reports in populations of similar geographic distribution. While MSA and/or MAA positivity did associate with particular clinical manifestations, it did not predict in our cohort specific IIM subgroup as defined by the latest EULAR/ACR classification criteria. Future studies are warranted to conclusively decide if these autoantibodies, measured with a standardized method, should or not be incorporated in every day clinical practice to aid IIM diagnosis.

Autoimmune serology is key to the diagnosis and management of autoimmune liver diseases. Its correct use in clinical practice requires a basic knowledge of the laboratory techniques used for autoantibody detection. Indirect immunofluorescence (IIF) on triple rodent tissue is still the gold standard screening procedure for liver-relevant autoantibodies, while HEp2 cells and human ethanol-fixed neutrophils are used as substrates to characterize nuclear reactivities and to detect anti-neutrophil cytoplasm antibody, respectively. Assays based on purified or recombinant antigens are increasingly used, having the main advantage of being observer-independent and the disadvantage of detecting only autoantibodies whose antigenic target has been identified. The AIH-specific anti-soluble liver antigen antibody cannot be detected by IIF and a molecular-based assay should be used at the screening level. Since autoantibodies may be present in the context of viral hepatitides and other inflammatory liver diseases it is important to exclude these conditions before diagnosing autoimmune liver disease. Anti-nuclear antibody (ANA), most often with a homogeneous IIF pattern on HEp2 cells, characterizes type 1 autoimmune hepatitis (AIH), and is found in association with anti-smooth muscle antibody in about half of the cases. Two IIF ANA patterns are specific for primary biliary cholangitis, namely the rim-like/membranous pattern, and the multiple nuclear dots pattern. Anti-liver kidney microsomal antibody type 1 is the serological hallmark of type 2 AIH, often in association with anti-liver cytosol type 1 antibody. Atypical perinuclear anti-neutrophil antibody, referred to as perinuclear anti-neutrophil nuclear antibody, is frequently detected in primary sclerosing cholangitis, in AIH type 1 and in inflammatory bowel diseases. The anti-asiaglycoprotein receptor antibody is liver-specific but not disease-specific, and reliable commercial assays for its detection are lacking. Anti-mitochondrial antibody is the hallmark of primary biliary cholangitis (PBC), being disease-specific and present in about 95% of the PBC patients. Its incidental detection presages the future development of PBC., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

: Antiphospholipid syndrome, which often complicates systemic lupus erythematosus (SLE), features high occurrence of arterial and/or venous thrombosis and recurrent fetal loss. However, which antibody subclass contributes to which clinical event remains uncertain. We newly developed an up-to-date enzyme immunoassay system using the AcuStar automated analyzer (Instrumentation Laboratory, Bedford, Massachusetts, USA) for parallel detection of six subclasses of antiphospholipid antibodies (aPLs): anticardiolipin antibodies (aCL) of IgG, IgM, and IgA and anti-β2-glycoprotein I antibodies (aβ2GPI) of IgG, IgM, and IgA. They were measured in 276 healthy volunteers and 138 patients with SLE: 45 with thromboembolic complications (29 arterial; 16 venous) and 93 without. Lupus anticoagulant activity in their plasma was measured according to the guidelines recommended by the Subcommittee on Lupus Anticoagulant/Phospholipid-Dependent Antibodies. aCL/β2GPI was measured with a standard ELISA kit commonly used in Japan. The positive results of IgG aCL, IgA aCL, and IgG aβ2GPI were closely associated with thromboembolic complications, whereas IgM aCL and IgM aβ2GPI were not. receiver operating characteristic analysis revealed that the accuracy of predicting thromboembolic complications based on the composite test results of the former three antibodies were obviously higher than by each alone. Regarding agreement with the test results of lupus anticoagulant activity, IgG aβ2GPI showed the closest match. Patients with SLE frequently possess various combinations of the six aPL subclasses, and this antibody spectrum is closely associated with thromboembolic events in these patients. This new automated enzyme immunoassay system allows simultaneous analysis of the profile of aPL subclasses for the differential diagnosis of antiphospholipid antibody syndrome in its early stage.

Objective: LcSSc is associated with ACAs and a mild course, whereas dcSSc is associated with anti-topoisomerase antibodies (ATAs) and a more severe course. However, ATAs are also present in lcSSc. Little is known about survival and organ involvement in this subgroup. The aim of this study is to determine whether survival and organ involvement of lcSSc ATA-positive patients differs from lcSSc ATA-negative or dcSSc ATA-positive patients. Furthermore, transition from lcSSc to dcSSc was evaluated., Methods: Data from The Nijmegen Systemic Sclerosis cohort were used, with up to 15 years of follow-up. Kaplan-Meier analysis was performed for survival and organ involvement, including interstitial lung disease, pulmonary arterial hypertension, cardiac involvement and Scleroderma Renal Crises. Cox proportional hazard modelling was performed to adjust for confounders., Results: A total of 460 patients were included: 58 (13%) lcSSc ATA-positive patients, 237 (52%) lcSSc ATA-negative patients and 78 (17%) dcSSc ATA-positive patients. Cumulative survival in lcSSc ATA-positive patients was 75%, in lcSSc ATA-negative patients 58% and in dcSSc ATA-positive patients 53%. Interstitial lung disease was more prevalent in lcSSc ATA-positive patients (49%) than in lcSSc ATA-negative patients (25%), but less than in dcSSc ATA-positive patients (60%). Forty-eight patients developed dcSSc: 24 ATA-negative and 24 ATA-positive (P < 0.001)., Conclusion: LcSSc ATA-positive patients differ from lcSSc ATA-negative patients and dcSSc ATA-positive patients concerning survival and organ involvement. LcSSc patients who are ATA-positive are more likely to develop dcSSc than lcSSc patients who are ATA negative., (© The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Recently, we described a novel autoantibody, anti-Sj/ITPR1-IgG, that targets the inositol 1,4,5-trisphosphate receptor type 1 (ITPR1) in patients with cerebellar ataxia. However, ITPR1 is expressed not only by Purkinje cells but also in the anterior horn of the spinal cord, in the substantia gelatinosa and in the motor, sensory (including the dorsal root ganglia) and autonomic peripheral nervous system, suggesting that the clinical spectrum associated with autoimmunity to ITPR1 may be broader than initially thought. Here we report on serum autoantibodies to ITPR1 (up to 1:15,000) in three patients with (radiculo)polyneuropathy, which in two cases was associated with cancer (ITPR1-expressing adenocarcinoma of the lung, multiple myeloma), suggesting a paraneoplastic aetiology., Methods: Serological and other immunological studies, and retrospective analysis of patient records., Results: The clinical findings comprised motor, sensory (including severe pain) and autonomic symptoms. While one patient presented with subacute symptoms mimicking Guillain-Barré syndrome (GBS), the symptoms progressed slowly in two other patients. Electrophysiology revealed delayed F waves; a decrease in motor and sensory action potentials and conduction velocities; delayed motor latencies; signs of denervation, indicating sensorimotor radiculopolyneuropathy of the mixed type; and no conduction blocks. ITPR1-IgG belonged to the complement-activating IgG1 subclass in the severely affected patient but exclusively to the IgG2 subclass in the two more mildly affected patients. Cerebrospinal fluid ITPR1-IgG was found to be of predominantly extrathecal origin. A 3 H-thymidine-based proliferation assay confirmed the presence of ITPR1-reactive lymphocytes among peripheral blood mononuclear cells (PBMCs). Immunophenotypic profiling of PBMCs protein demonstrated predominant proliferation of B cells, CD4 T cells and CD8 memory T cells following stimulation with purified ITPR1 protein. Patient ITPR1-IgG bound both to peripheral nervous tissue and to lung tumour tissue. A nerve biopsy showed lymphocyte infiltration (including cytotoxic CD8 cells), oedema, marked axonal loss and myelin-positive macrophages, indicating florid inflammation. ITPR1-IgG serum titres declined following tumour removal, paralleled by clinical stabilization., Conclusions: Our findings expand the spectrum of clinical syndromes associated with ITPR1-IgG and suggest that autoimmunity to ITPR1 may underlie peripheral nervous system diseases (including GBS) in some patients and may be of paraneoplastic origin in a subset of cases.

Lupus-specific anti-ribosomal P (anti-Rib-P) autoantibodies have been implicated in the pathogenesis of neurological complications in systemic lupus erythematosus (SLE). The aim of the present study was to determine variable (V)-region signatures of secreted autoantibody proteomes specific for the Rib-P heterocomplex and investigate the molecular basis of the reported cross-reactivity with Sm autoantigen. Anti-Rib-P immunoglobulins (IgGs) were purified from six anti-Rib-P-positive sera by elution from enzyme-linked immunosorbent assay (ELISA) plates coated with either native Rib-P proteins or an 11-amino acid peptide (11-C peptide) representing the conserved COOH-terminal P epitope. Rib-P- and 11-C peptide-specific IgGs were analysed for heavy (H) and light (L) chain clonality and V-region expression using an electrophoretic and de-novo and database-driven mass spectrometric sequencing workflow. Purified anti-Rib-P and anti-SmD IgGs were tested for cross-reactivity on ELISA and their proteome data sets analysed for shared clonotypes. Anti-Rib-P autoantibody proteomes were IgG1 kappa-restricted and comprised two public clonotypes defined by unique H/L chain pairings. The major clonotypic population was specific for the common COOH-terminal epitope, while the second shared the same pairing signature as a recently reported anti-SmD clonotype, accounting for two-way immunoassay cross-reactivity between these lupus autoantibodies. Sequence convergence of anti-Rib-P proteomes suggests common molecular pathways of autoantibody production and identifies stereotyped clonal populations that are thought to play a pathogenic role in neuropsychiatric lupus. Shared clonotypic structures for anti-Rib-P and anti-Sm responses suggest a common B cell clonal origin for subsets of these lupus-specific autoantibodies., (© 2016 British Society for Immunology.)

We report a case involving a 62-year-old woman with in vivo-bound immunoglobulin (Ig)G and IgA antibodies in both the intercellular space (ICS) and basement membrane zone (BMZ). Her clinical and histopathological features were identical with those of pemphigus vulgaris, while the immunopathological findings suggested IgG/IgA pemphigus. Direct immunofluorescence (IF) showed in vivo-bound IgG and IgA antibodies in the ICS and BMZ, whereas indirect IF showed circulating IgG but not IgA antibodies in the ICS and BMZ. The anti-ICS IgG bound to desmoglein-3, while the anti-BMZ antibodies bound to the epidermal side of 1 mol/L NaCl-split skin. To the best of our knowledge, only two similar cases have been reported so far. Furthermore, we also examined IgG subclass distribution of the in vivo-bound and circulating anti-ICS and BMZ antibodies, and found that IgG1, IgG2 and IgG4 bound to ICS of the lesional skins, while IgG1 and IgG3 bound to the BMZ. The circulating anti-ICS antibodies belonged to IgG1 and IgG4, while the circulating anti-BMZ antibodies to IgG1, IgG2 and IgG4. We report a case involving a 62-year-old woman with in vivo-bound immunoglobulin (Ig)G and IgA antibodies in both the intercellular space (ICS) and basement membrane zone (BMZ). Her clinical and histopathological features were identical with those of pemphigus vulgaris, while the immunopathological findings suggested IgG/IgA pemphigus. Direct immunofluorescence (IF) showed in vivo-bound IgG and IgA antibodies in the ICS and BMZ, whereas indirect IF showed circulating IgG but not IgA antibodies in the ICS and BMZ. The anti-ICS IgG bound to desmoglein-3, while the anti-BMZ antibodies bound to the epidermal side of 1 mol/L NaCl-split skin. To the best of our knowledge, only two similar cases have been reported so far. Furthermore, we also examined IgG subclass distribution of the in vivo-bound and circulating anti-ICS and BMZ antibodies, and found that IgG1, IgG2 and IgG4 bound to ICS of the lesional skins, while IgG1 and IgG3 bound to the BMZ. The circulating anti-ICS antibodies belonged to IgG1 and IgG4, while the circulating anti-BMZ antibodies to IgG1, IgG2 and IgG4., (© 2015 Japanese Dermatological Association.)

Bullous pemphigoid (BP) is an autoimmune subepidermal bullous disease, and different immunoglobulin (Ig)G autoantibody subclasses may play different roles in the pathogenesis of BP. This study aims to evaluate the relationship between specific IgG subclasses and BP. Enzyme-linked immunoassays (ELISA) were developed to test the IgG subclasses targeting the non-collagenous 16A (NC16A) domain of BP180. A statistical analysis was carried out to assess the relationship of BP and IgG subclasses as well as other factors. The correlation coefficients between the ELISA scores for four IgG subclasses and disease severity scores were 0.586 for IgG, 0.441 for IgG1, 0.594 for IgG2, 0.345 for IgG3, and 0.448 for IgG4 before treatment. After treatment, the correlation coefficient was 0.376 for IgG, 0.522 for IgG1, 0.314 for IgG2, 0.582 for IgG3 and 0.503 for IgG4. Spearman's rank correlation coefficient was 0.801 for IgG1, 0.66 for IgG2, 0.575 for IgG3 and 0.463 for IgG4 between the ELISA scores of IgG subclasses and the disease severity score variation. The ELISA scores of IgG subclasses in patients with mucosal involvement were higher than those without. Survival analysis showed that sex, IgG1 and IgG4 were the independent predictors for BP. In conclusion, the serum levels of IgG1 and IgG4 targeting BP180NC16A were paralleled with disease severity in BP patients. IgG1 and IgG4 and sex were the independent prognostic factors for an early prognosis of BP., (© 2015 Japanese Dermatological Association.)

Introduction: Systemic sclerosis is a rare auto immune disease characterized by a local or diffuse skin condition and a variable visceral impairment. Anti nuclear antibodies (ANA) can be found in 95 % of patients. The most frequent are the anti topoisomerase 1 or anti Scl 70 and the anti-centromeres. Other antibodies have been reported but they are not conventionally sought in clinical practice. They are referred to as " non identified " ANA., Objective: To seek the " non identified " antibodies in patients with scleroderma at Erasme Hospital, to assess their prevalence in this cohort and to correlate their presence with the clinical characteristics., Methods: 89 patients out of the cohort of Erasme hospital patients with scleroderma have been looked at. Their clinical and biological data have been identified and a detection of antibodies have been performed by first an immonudot technique and second an EliA technique., Results: 17 out of the 89 patients of our cohort had " non identified " ANA. Among them, antibodies in 11 patients have been identified by the immunodot, among which 7 anti-PmScl 75 and/or 100,3 RNA polymerase III and 1 antifibrillarin. The EliA technique identif ied antibodies in 10 patients among which 5 anti- PmScl, 2 anti RNA polymerase, 2 anti-fibrillarin and 1 anti-centromere., Conclusion: Auto antibodies other than the antitopoisomerase and anti-centromere have been found in patients with scleroderma in our cohort. Certain links exist between the presence of a given antibody and clinical features. We still have to define whether there exist other auto antibodies of which we still are unaware since in some patient no antibodies were detected.

Antibodies are part of the adaptive immune response that provides protection against microorganisms. In rare instances individuals can develop antibodies that bind to normal central nervous system structures. These antibodies have been classified into two groups depending on the subcellular location of their target antigens. Biomarker antibodies bind to cytosolic or nuclear targets. They do not impact on the normal function of the cell, but are most often paraneoplastic biomarkers that may suggest screening for different cancers. The second, more recently discovered group of antibodies recognize the three-dimensional structure of native proteins that are accessible on the cell surface. Understanding of this important difference is reflected in the nature of assays used to detect antibodies in these two groups. Western blots and, more recently, line blots, both of which use linear, denatured targets, are used to detect antibodies to intracellular targets. Newer assays have been developed that maintain the native structure of protein targets to permit detection of antibodies that recognize extracellular targets. In this chapter we describe the methods used to detect both antibody types, and discuss assay cut-offs, sample handling, and which biologic fluid to test., (© 2016 Elsevier B.V. All rights reserved.)

Autoantibody testing forms an important part of diagnostic workup of patients in Pediatric rheumatology practice. However it is important to understand that the mere presence of autoantibodies does not necessarily mean the presence of an underlying autoimmune disease. Autoantibodies may be present decades before the development of clinical manifestations of an autoimmune disease and may be viewed as harbingers of Autoimmune disease. On the other hand, low-affinity autoantibodies may be present in normal healthy individuals; these natural autoantibodies serve an important function in immune regulation and tolerance. Autoantibody testing in pediatric practice mainly includes testing for anti-nuclear antibodies, anti-dsDNA antibodies, anti-neutrophil cytoplasmic autoantibodies and antiphospholipid antibodies. Rheumatoid factor and anti-CCP do not have much significance in the diagnostic schema in pediatric rheumatology, except perhaps for classification of juvenile idiopathic arthritis (JIA) and prognostication in late-onset polyarticular JIA. The positive predictive value (PPV) of any laboratory test depends on the prevalence of the disease in the population being tested. Hence, test ordering practices greatly impact the performance characteristics and positive predictive value of any laboratory test. A restricted test ordering only in patients with clinical signs and symptoms suggestive of autoimmune disease would thus greatly increase the PPV of tests such as antinuclear antibody used for diagnosing autoimmunity.

A deficiency in ADAMTS13 (A Disintegrin And Metalloprotease with ThromboSpondin type-1 repeats, member 13) is associated with thrombotic thrombocytopenic purpura (TTP). Congenital TTP is caused by a defect in the ADAMTS13 gene resulting in decreased or absent enzyme activity; acquired TTP results from autoantibodies that either inhibit the activity or increase the clearance of ADAMTS13. Despite major progress in recent years in our understanding of the disease, many aspects around the pathophysiology of TTP are still unclear. Newer studies expanded the TTP field from ADAMTS13 and inhibitory antibodies to immune complexes, cloned autoantibodies, and a possible involvement of other proteases. Additionally, several new treatment strategies supplementing plasma-exchange and infusion are under investigation for a better and more specific treatment of TTP patients. In this review, we discuss the recent insights in TTP pathophysiology and describe upcoming therapeutic opportunities.

Objectives: This paper aims to identify clinical and serological differences, damage accrual and mortality, in juvenile, adult and late-onset SLE., Methods: We conducted our study with patients fulfilling SLE classification criteria taken from the Hospital Gregorio Marañon Autoimmune Systemic Rheumatic Diseases' Registry (1986 to 2012). Clinical characteristics, laboratory data and therapies used during the course of the disease were analysed with patients divided into 3 groups: juvenile-onset (≤ 18 years), adult-onset (19-50) and late onset (>50 years)., Results: Four hundred and forty-five patients were included. Renal disease and cutaneous manifestations were more frequent in the juvenile-onset group at disease onset. During follow-up, juvenile-onset group presented a higher incidence of renal disease, malar rash, Raynaud's phenomenon, cutaneous vasculitis, and neuropsychiatric manifestations than the other two groups. Arthritis and lymphopoenia were more frequent in the adult-onset group. Arterial hypertension and neoplasm were more frequent in the late-onset group. Low serum complement, anti-dsDNA, anti-U1RNP and anti-Sm antibodies were more common in the juvenile-onset group. Patients with late-onset SLE had more damage accrual. Thirty-seven patients (8.3%) died during the study. All-cause mortality was significantly higher in the late-onset group. Age at disease onset >50 years was an independent risk factor for damage accrual (OR, 2.2; 95%CI, 1.1-4.6; p=0.029) and mortality (OR, 2.6; 95%CI, 1.1-6.3; p=0.03)., Conclusions: We found significant differences in clinical and serological profiles between juvenile, adult and late-onset SLE. The most significant of which was a higher prevalence of neuropsychiatric and renal complications as well as different autoantibody signatures for the juvenile-onset group.

Background: Autoantibodies have been implicated in the etiologic pathway of depressive disorders. Here, we determine the association between the presence of a panel of autoantibodies at baseline and change in depression symptom score over 5-year follow-up in a cohort of healthy elderly Australians., Methods: Serum samples from 2049 randomly selected subjects enrolled in the Hunter Community Study (HCS) aged 55-85 years were assayed for a range of autoimmune markers (anti-nuclear autoantibodies, extractable nuclear antigen autoantibodies, anti-neutrophil cytoplasmic autoantibodies, thyroid peroxidase autoantibodies, tissue transglutaminase autoantibodies, anti-cardiolipin autoantibodies, rheumatoid factor and cyclic citrullinated peptide autoantibodies) at baseline. Depression symptom score was assessed using the Centre for Epidemiological Study (CES-D) scale at baseline and 5 years later., Results: Autoantibody prevalence varied amongst our sample with ANA being the most prevalent; positive in 16% and borderline in 36% of study population. No evidence for a relationship was found between change in CES-D score over time and any autoimmune marker. Statins and high cholesterol were significantly associated with change in CES-D score over time in univariate analysis; however, these were probably confounded since they failed to remain significant following multivariable analysis., Conclusions: Autoantibodies were not associated with change in CES-D score over time. These findings point to an absence of autoimmune mechanisms in the general population or in moderate cases of depression., (Copyright © 2015. Published by Elsevier Masson SAS.)

SLE is a systemic autoimmune disease with high prevalence of hypertension. Around 40-75 % of SLE patients develop nephritis, a major cause of hypertension and mortality. Angiotensin-converting enzyme (ACE) maintains the blood pressure and blood volume homeostasis. An insertion/deletion (I/D) polymorphism in intron 16 of ACE gene was reported to influence the development of hypertension, nephritis, and cardiovascular diseases in different ethnic populations. Despite compelling evidence for the high prevalence of hypertension in individuals with SLE, underlying factors for its development are not well studied. With this background, we analyzed the influence of ACE insertion/deletion polymorphism on susceptibility to SLE, development of nephritis and hypertension, other clinical features and autoantibody phenotype in South Indian SLE patients. Three hundred patients with SLE and 460 age and sex similar ethnicity matched individuals were included as patients and healthy controls, respectively. The ACE gene insertion/deletion polymorphism was analyzed by PCR. Insertion (I) and deletion (D) alleles were observed to be equally distributed among patients (57 and 43 %) and controls (59 and 41 %), respectively. The mutant (D) allele did not confer significant risk for SLE (II vs. ID: p = 0.4, OR 1.15, 95 % CI 0.8-1.6; II vs. DD: p = 0.34, OR 1.22, 95 % CI 0.8-1.85). There was no association of the ACE genotype or the allele with development of lupus nephritis (II vs. ID: p = 0.19, OR 1.41, 95 % CI 0.84-2.36; II vs. DD: p = 0.41, OR 0.74, 95 % CI 0.38-1.41) or hypertension (II vs. ID: p = 0.85, OR 0.9, 95 % CI 0.43-1.8; II vs. DD: p = 0.66, OR 1.217, 95 % CI 0.5-2.8). The presence of mutant allele (D) was not found to influence any clinical features or autoantibody phenotype. The insertion/deletion polymorphism of the ACE gene is not a genetic risk factor for SLE and does not influence development of hypertension or lupus nephritis in South Indian Tamils.

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease with highest prevalence among women of childbearing age. However, children younger than 16 years also can develop SLE (childhood-onset lupus/juvenile-type SLE). The aim of our study was to compare the clinical course of adult and pediatric-onset SLE. Data from 342 adult patients followed at the University of Debrecen, Hungary, and 79 children documented in the Hungarian National Pediatric SLE registry were analyzed using hospital medical records. Organ manifestations, laboratory parameters, and immunoserological characteristics were reviewed and the results were evaluated using SPSS for Windows software.Gender distribution was not significantly different between groups with disease starting in childhood vs adulthood. The prevalence of the following manifestations was significantly higher for pediatric than for adult-onset disease including: lupus nephritis (43% pediatric vs 26.4% for adult-onset), hematological disorders (57% vs 36.4%), photosensitivity (20% vs 9%), butterfly rash (61% vs 35.5%) and mucosal ulceration (11.4% vs 4%). For adult-onset SLE, neurological symptoms (30% vs 6%) and polyarthritis (86% vs 68%) occurred significantly more frequently than in children. Anti-SSA, anti-SSB and antiphospholipid antibodies were detected at significantly higher levels in adult-onset patients compared to those in pediatrics. Children were more commonly given high-dose intravenous immunoglobulin treatment (6.3% vs 0.6%) and mycophenolate mofetil (15.2% vs 5.3%) than adults.These results suggest that pediatric and adult-onset SLE differ in multiple aspects, and it is important to recognize these differences for optimal treatment and prognosis of these patients., (© The Author(s) 2014.)

The exposure of atmospheric pollutants on the organism may be a precondition for the development of pathological processes in organs and system to which they have tropicity. The change in the levels of specific autoantibodies occur long before the clinical manifestation of the disease. The aim of the study was the investigation of relationships between the levels of specific autoantibodies and risks of the formation of pathological processes of organs and systems in conditions of the inhalation exposure to chemicals. There was made an assessment of levels of the air pollution and indoor air in the industrial centers of Eastern Siberia. There were calculated indices of danger from the inhalation exposure of chemical compounds and the risks for the development of the pathology of organs and systems. There was studied the relative content of specific autoantibodies to the organs and systems that are at high risk of the development ofpathological processes. The highest overall risks for the development of respiratory diseases, immune system and cardiovascular system were established in schoolchildren residing in areas of high and medium levels of air pollution. In general, the identified changes in the content of specific autoantibodies characterizing the state of the major organs and systems ofchildren residing in areas of high riskfor the development of pathological processes associated with the content of chemical compounds in the air cannot be properly interpreted as the realized risk of environmental impacts and require further study.

Context: Reliable thyroglobulin (Tg) autoantibody (TgAb) detection before Tg testing for differentiated thyroid cancer (DTC) is critical when TgAb status (positive/negative) is used to authenticate sensitive second-generation immunometric assay ((2G)IMA) measurements as free from TgAb interference and when reflexing "TgAb-positive" sera to TgAb-resistant, but less sensitive, Tg methodologies (radioimmunoassay [RIA] or liquid chromatography-tandem mass spectrometry [LC-MS/MS])., Objective: The purpose of this study was to assess how different Kronus (K) vs Roche (R) TgAb method cutoffs for "positivity" influence false-negative vs false-positive serum TgAb misclassifications that may reduce the clinical utility of reflex Tg testing., Methods: Serum Tg(2G)IMA, TgRIA, and TgLC-MS/MS measurements for 52 TgAb-positive and 37 TgAb-negative patients with persistent/recurrent DTC were compared. A total of 1426 DTC sera with TgRIA of ≥ 1.0 μg/L had false-negative and false-positive TgAb frequencies determined using low Tg(2G)IMA/TgRIA ratios (<75%) to indicate TgAb interference., Results: TgAb-negative patients with disease displayed Tg(2G)IMA, TgRIA, and TgLC-MS/MS serum discordances (% coefficient of variation = 24 ± 20%, range, 0%-100%). Of the TgAb-positive patients with disease, 98% had undetectable/lower Tg(2G)IMA vs either TgRIA or TgLC-MS/MS (P < .01), whereas 8 of 52 (15%) had undetectable Tg(2G)IMA + TgLC-MS/MS associated with TgRIA of ≥ 1.0 μg/L. Receiver operating characteristic curve analysis reported more sensitivity for TgAb method K vs R (81.9% vs 69.1%, P < .001), but receiver operating characteristic curve cutoffs (>0.6 kIU/L [K] vs >40 kIU/L [R]) had unacceptably high false-negative frequencies (22%-32%), whereas false positives approximated 12%. Functional sensitivity cutoffs minimized false negatives (13.5% [K] vs 21.3% [R], P < .01) and severe interferences (Tg(2G)IMA, <0.10 μg/L) (0.7% [K] vs 2.4% [R], P < .05) but false positives approximated 23%., Conclusions: Reliable detection of interfering TgAbs is method and cutoff dependent. No cutoff eliminated both false-negative and false-positive TgAb misclassifications. Functional sensitivity cutoffs were optimal for minimizing false negatives but have inherent imprecision (20% coefficient of variation) that, exacerbated by TgAb biologic variability during DTC monitoring, could cause TgAb status to fluctuate for patients with low TgAb concentrations, prompting unnecessary Tg method changes and disrupting Tg monitoring. Laboratories using reflexing should limit Tg method changes by considering a patient's Tg + TgAb testing history in addition to current TgAb status before Tg method selection.

Systemic autoimmune rheumatic diseases encompass a vast array of autoantibodies which are very useful to confirm a suspected diagnosis. This article gives an overview of the most common autoantibodies, how they are tested and the significance of a positive test in a clinical context.

Objectives: Antibodies against citrullinated antigens (ACPA) represent one rheumatoid arthritis (RA) classification criteria. Recently, mutated and citrullinated vimentin (MCV), containing approx. 45 potentially citrullinated sites, was characterised as another modified autoantigenic RA target. Therefore, we wanted to screen, select and validate predominant MCV autoantigenic epitopes (called here MCE) as possible new diagnostic targets., Methods: MCV-derived peptides with citrullinated sites were screened in healthy controls and patients. Based on this, twelve selected MCE were used for validation of ACPA isotypes (IgA/IgG/IgM) with ELISA in early RA (ERA, <12 months) and established RA (>12 months) Russian patients. Sensitivity of MCE reactivity was compared to commercially available ELISAs for anti-CCP IgG, anti-MCV IgG, and anti-RF IgA/IgM/IgG., Results: Anti-MCE IgG/IgA//IgM antibodies were observed in 64.1%, 23.1%, and 15.4% ERA, and 63.9%, 26.7%, and 13.1% established RA patients, respectively. Anti-MCV IgG was present in 64.1% ERA and 55.0% RA patients. Furthermore, anti-CCP IgG and RF IgG/IgA/IgM were detectable in up to 76.9%, 71.8%, 71.8%, and 38.5% ERA, and 80.1%, 72.3%, 67.5%, and 43.0% RA patients. Anti-CCP IgG single positivity was observed in 7.7% ERA and 6.3% RA patients. Only one RA patient was anti-MCE single positive., Conclusions: MCV autoantigenic epitopes were emulated by cyclic citrullinated MCV-derived peptides and recognised by all autoantibody-Ig subclasses in RA. Tested MCE were recognized more frequently by IgG as the original MCV antigen. High antibody prevalence against CCP epitopes suggests a strong CCP-linkage to RA pathogenesis in the investigated Russian cohort.

Objectives: Several factors have been implicated in the prognosis of idiopathic inflammatory myopathies, including age, gender, delay in diagnosis, neoplasia, creatine kinase levels and some autoantibodies. We have reviewed the main factors contributing to mortality in patients with idiopathic inflammatory myopathy (IIM) diagnosed between 1976 and 2007 who were followed for at least 5 years in the Rheumatology Unit at University College Hospital in London., Methods: An observational retrospective study was carried out on patients with IIM diagnosed between 1976 and 2007. All the patients fullfilled at least three out of four of the Bohan and Peter criteria. The subjects were divided into the following groups: adult-onset polymyositis (APM); adult-onset dermatomyositis (ADM); juvenile dermatomyositis (JDM); Overlap syndromes with another autoimmune rheumatic disease., Results: 90 patients were identified. The female to male ratio was 2.5:1 and the mean age at diagnosis was 38.5 years (SD 15.03). 47.8% of the patients had APM, 30% adult-onset ADM, 15.6% Overlap and 6.7% JDM. Among the extramuscular features, 18.9% had pulmonary involvement. In 70% the highest CK was >5 times the upper normal. Prednisolone was prescribed in 98.9%. 11.1% received rituximab. 34.4% had monophasic, 31.1% relapsing and remitting and 34.4% continuous progressive course of the disease. The median follow-up was 11.5 years (IQR 12.00). 14.4% of the patients died, 30.8% due to infection, 30.8% from a cardiovascular event and 23.1% due to neoplasia. The 1, 5 and 10-year survival was 100%, 97.8% and 91%, respectively. Male gender (Hazards Ratio (HR) 3.222; p=0.037), pulmonary involvement (HR 5.247; p=0.009), chronic progressive course (HR 3.711; p=0.030) and use of rituximab (HR 3.562; p=0.036) were the only risk factors to be statistically significantly associated (p<0.05) with death., Conclusions: We conclude that long-term survival in these patients is generally quite good with an estimated 10-year survival >90% in our cohort, which is even higher than previously reported.

Myasthenia gravis is characterized by muscle weakness and abnormal fatigability. It is an autoimmune disease caused by the presence of antibodies against components of the muscle membrane localized at the neuromuscular junction. In most cases, the autoantibodies are against the acetylcholine receptor (AChR). Recently, other targets have been described such as the MuSK protein (muscle-specific kinase) or the LRP4 (lipoprotein related protein 4). Myasthenia gravis can be classified according to the profile of the autoantibodies, the location of the affected muscles (ocular versus generalized), the age of onset of symptoms and thymic abnormalities. The disease generally begins with ocular symptoms (ptosis and/or diplopia) and extends to other muscles in 80% of cases. Other features that characterize MG include the following: variability, effort induced worsening, successive periods of exacerbation during the course of the disease, severity dependent on respiratory and swallowing impairment (if rapid worsening occurs, a myasthenic crisis is suspected), and an association with thymoma in 20% of patients and with other autoimmune diseases such as hyperthyroidism and Hashimoto's disease. The diagnosis is based on the clinical features, the benefit of the cholinesterase inhibitors, the detection of specific autoantibodies (anti-AChR, anti-MuSK or anti-LRP4), and significant decrement evidenced by electrophysiological tests. In this review, we briefly describe the history and epidemiology of the disease and the diagnostic and clinical classification. The neonatal form of myasthenia is explained, and finally we discuss the main difficulties of diagnosis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The B-cell receptor (BCR) for antigen is a key sensor required for B-cell development, survival, and activation. Rigorous selection checkpoints ensure that the mature B-cell compartment in the periphery is largely purged of self-reactive B cells. However, autoreactive B cells escape selection and persist in the periphery as anergic or clonally ignorant B cells. Under the influence of genetic or environmental factors, which are not completely understood, autoreactive B cells may be activated. Similar activation can also occur at different stages of B-cell maturation in the bone marrow or in peripheral lymphoid organs and give rise to malignant B cells. The pathology that typifies neoplastic lymphocytes and autoreactive B cells differs: malignant B cells proliferate and occupy niches otherwise taken up by healthy leukocytes or erythrocytes, while autoreactive B cells produce pathogenic antibodies or present self-antigen to T cells. However, both malignant and autoreactive B cells share the commonality of deregulated BCR pathways as principal contributors to pathogenicity. We first summarize current views of BCR activation. We then explore how anomalous BCR pathways correlate with malignancies and autoimmunity. We also elaborate on the activation of TLR pathways in abnormal B cells and how they contribute to maintenance of pathology. Finally, we outline the benefits and emergence of mouse models generated by somatic cell nuclear transfer to study B-cell function in manners for which current transgenic models may be less well suited., (© 2014 Elsevier Inc. All rights reserved.)

We investigated the characteristics of Chinese SLE patients by analyzing the association between specific autoantibodies and clinical manifestations of 2104 SLE patients from registry data of CSTAR cohort. Significant (P<0.05) associations were found between anti-Sm antibody, anti-rRNP antibody, and malar rash; between anti-RNP antibody, anti-SSA antibody, and pulmonary arterial hypertension (PAH); between anti-SSB antibody and hematologic involvement; and between anti-dsDNA antibody and nephropathy. APL antibody was associated with hematologic involvement, interstitial lung disease, and a lower prevalence of oral ulcerations (P<0.05). Associations were also found between anti-dsDNA antibody and a lower prevalence of photosensitivity, and between anti-SSA antibody and a lower prevalence of nephropathy (P<0.05). Most of these findings were consistent with other studies in the literature but this study is the first report on the association between anti-SSA and a lower prevalence of nephropathy. The correlations of specific autoantibodies and clinical manifestations could provide clues for physicians to predict organ damages in SLE patients. We suggest that a thorough screening of autoantibodies should be carried out when the diagnosis of SLE is established, and repeated echocardiography annually in SLE patients with anti-RNP or anti-SSA antibody should be performed.

Objectives: Esophageal squamous cell carcinoma (ESCC) is one of the most frequent causes of cancer death worldwide and effective diagnosis is needed. We assessed the diagnostic potential of an autoantibody panel that may benefit early diagnosis., Methods: We analyzed data for patients with ESCC and normal controls in a test cohort and a validation cohort. Autoantibody levels were measured against a panel of six tumor-associated antigens (p53, NY-ESO-1, matrix metalloproteinase-7 (MMP-7), heat shock protein 70 (Hsp70), peroxiredoxin VI (Prx VI), and BMI1 polycomb ring finger oncogene (Bmi-1)) by enzyme-linked immunosorbent assay., Results: We assessed serum autoantibodies in 513 participants: 388 with ESCC and 125 normal controls. The validation cohort comprised 371 participants: 237 with ESCC, and 134 normal controls. Autoantibodies to at least 1 of 6 antigens demonstrated a sensitivity/specificity of 57% (95% confidence interval (CI): 52-62%)/95% (95% CI: 89-98%) and 51% (95% CI: 45-57%)/96% (95% CI: 91-99%) in the test and validation cohorts, respectively. Measurement of the autoantibody panel could differentiate early-stage ESCC patients from normal controls (sensitivity 45% (95% CI: 32-59%) and specificity 95% (95% CI: 89-98%) in the test cohort; 46% (95% CI: 35-58%) and 96% (95% CI: 91-99%) in the validation cohort). In either cohort, no significant differences were seen when patients were subdivided by age, gender, smoking status, size of tumor, site of tumor, depth of tumor invasion, histological grade, lymph node status, TNM stage, or early-stage and late-stage groups., Conclusions: Measurement of an autoantibody response to multiple tumor-associated antigens in an optimized panel assay, to help discriminate early-stage ESCC patients from normal controls, may aid in early detection of ESCC.

Objective: The objective of this paper is to determine whether patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) possess differential IgM- and IgG-specific reactivity against peptides from the U1 small nuclear ribonucleoprotein particle (U1 snRNP)., Methods: The IgM- and IgG-mediated responses against 15 peptides from subunits of the U1 snRNP were assessed by indirect enzyme linked immunosorbent assays (ELISAs) in sera from patients with SLE and MCTD and healthy individuals (n = 81, 41, and 31, respectively). Additionally, 42 laboratory tests and 40 clinical symptoms were evaluated to uncover potential differences. Binomial logistic regression analyses (BLR) were performed to construct models to support the independent nature of SLE and MCTD. Receiver operating characteristic (ROC) curves corroborated the classification power of the models., Results: We analyzed IgM and IgG anti-U1 snRNP titers to classify SLE and MCTD patients. IgG anti-U1 snRNP reactivity segregates SLE and MCTD from nondisease controls with an accuracy of 94.1% while IgM-specific anti-U1 snRNP responses distinguish SLE from MCTD patients with an accuracy of 71.3%. Comparison of the IgG and IgM anti-U1 snRNP approach with clinical tests used for diagnosing SLE and MCTD revealed that our method is the best classification tool of those analyzed (p ≤ 0.0001)., Conclusions: Our IgM anti-U1 snRNP system along with lab tests and symptoms provide additional molecular and clinical evidence to support the hypothesis that SLE and MCTD may be distinct syndromes.

Laboratory testing for immune-mediated thrombocytopenias involves identification and classification of antibodies present in patient sera or attached to patient platelets. This article summarizes the available types of platelet antibody testing and applications in disorders such as neonatal alloimmune thrombocytopenia, post-transfusion purpura, multiple platelet transfusion refractoriness, immune thrombocytopenia, and drug-induced thrombocytopenia., (Copyright © 2013 Wiley Periodicals, Inc.)

Problem: Increasing evidence supports the involvement of complex antibody-mediated immunologic events at the decidua-trophoblast interface. Our objective is to define the humoral immune responses of pregnant women with a history of recurrent pregnancy loss (RPL) compared with gestation-age-matched and non-pregnant controls in terms of trophoblast-derived antigenic targets and IgG subclasses., Method of Study: Immunoprecipitation and Western immunoblotting were performed to characterize IgG subclass reactivity to Sw.71 trophoblast-derived fetal fibronectin and alpha-2-macroglobulin, using serum obtained from first-trimester pregnant RPL subjects, gestation-age-matched controls, and non-pregnant controls., Results: Using a generalized linear model, sera from women with a history of RPL exhibited increased IgG(3) immunoreactivity to trophoblast-derived fetal fibronectin and alpha-2-macroglobulin compared with controls (P < 0.001 and P < 0.001, respectively)., Conclusion: IgG(3) reactivity in women with RPL may play a significant role in aberrant immune-regulatory mechanisms in early pregnancy. Further investigations into the role of autoantibodies against trophoblast-derived proteins in implantation and pregnancy are warranted., (© 2012 John Wiley & Sons A/S.)

Background: To clarify the clinical relevance of anti-aquaporin-4 (anti-AQP4) antibody titers and immunoglobulin (IgG) subclass., Methods: Using a bridging enzyme-linked immunosorbent assay (ELISA), a flow cytometric assay (FCMA) and an immunofluorescence assay (IFA) for anti-AQP4 antibodies, sera from 142 patients with multiple sclerosis (MS) as defined by the McDonald criteria (2005), 29 with neuromyelitis optica (NMO) who fulfilled the 1999 criteria, 19 with recurrent and/or longitudinally extensive myelitis (RM/LM), 86 with other non-inflammatory neurological diseases (OND) and 28 healthy controls (HC) were studied., Results: Anti-AQP4 antibody positivity rates by IFA, FCMA, and ELISA were 41.4%, 51.7% and 48.3%, respectively, in NMO (1999) patients, and 0% in the OND and HC groups. Twenty-six MS patients (18.3%) were positive for the antibody; 17 met the 2006 NMO criteria, including positivity for anti-AQP4 antibody, and five had longitudinally extensive myelitis (LM). Among the cases with anti-AQP4 antibody detected by FCMA, IgG1, 2, 3, and 4 anti-AQP4 antibodies were found in 97.8%, 37.0%, 6.5% and 6.5% respectively. There was no association of either antibody positivity or level of anti-AQP4 antibody IgG subclasses with clinical parameters after adjustment of p values for multiple comparisons., Conclusions: FCMA and bridging ELISA are useful for detecting and quantifying anti-AQP4 antibodies.

The phospholipase A(2) receptor (PLA(2)R) is the major target antigen in idiopathic membranous nephropathy. The technique for measuring antibodies against PLA(2)R and the relationship between antibody titer and clinical characteristics are not well established. Here, we measured anti-PLA(2)R (aPLA(2)R) antibody titer and subclass in a well defined cohort of 117 Caucasian patients with idiopathic membranous nephropathy and nephrotic-range proteinuria using both indirect immunofluorescence testing (IIFT) and ELISA. We assessed agreement between tests and correlated antibody titer with clinical baseline parameters and outcome. In this cohort, aPLA(2)R antibodies were positive in 74% and 72% of patients using IIFT and ELISA, respectively. Concordance between both tests was excellent (94% agreement, κ=0.85). Among 82 aPLA(2)R-positive patients, antibody titer significantly correlated with baseline proteinuria (P=0.02). Spontaneous remissions occurred significantly less frequently among patients with high antibody titers (38% versus 4% in the lowest and highest tertiles, respectively; P<0.01). IgG4 was the dominant subclass in the majority of patients. Titers of IgG4, but not IgG1 or IgG3, significantly correlated with the occurrence of spontaneous remission (P=0.03). In summary, these data show high agreement between IIFT and ELISA assessments of aPLA(2)R antibody titer and highlight the pathogenetic role of these antibodies, especially the IgG4 subclass, given the observed relationships between aPLA(2)R titer, baseline proteinuria, and outcome.

Objective: To evaluate the effects of selenium (Se) supplementation on concentrations of thyroid peroxidase antibodies (TPOAb) and TPOAb IgG subclasses in autoimmune thyroiditis (AIT) patients with different thyroid functional status., Methods: A blind and placebo-controlled prospective study was performed for a total of 134 cases with AIT and thyroid peroxidase antibodies above 300 U/ml. Their mean age was 41 years (range: 15-70). All of them were recruited from Department of Endocrinology, First Affiliated Hospital of China Medical University from June 2008 to June 2009 and divided into 2 groups according to thyroid function: euthyroidism or subclinical hypothyroidism (n = 89) and hypothyroidism (n = 45). Then they were randomized into 2 groups: selenium-treated and placebo-treated. And 49 cases in subclinical autoimmune thyroiditis group and 28 cases in hypothyroidism group received 200 µg oral selenium yeast daily for 6 months while others placebo. Serum concentrations of TPOAb, TPOAb IgG subclasses, thyroid-stimulating hormone (TSH), free thyroxine (FT(4)) and Se were measured at baseline and after 3 and 6 months of follow-up., Results: The TPOAb levels showed an overall decrease of 4.3% at 3 months and of 12.6% at 6 months (both P < 0.05) post-supplementation in subclinical autoimmune thyroiditis patients. In overt hypothyroidism patients, the overall decrease of TPOAb concentrations was 21.9% at 3 months and 20.4% at 6 months (both P < 0.05) compared with those at pre-treatment. The predominant TPOAb IgG subclasses in sera from the AIT patients were IgG1, IgG3 and IgG4 and the positive percentages 72%, 41% and 72% respectively. The positive rate and concentrations of IgG3 in the patients with hypothyroidism were significantly higher than those of subclinical autoimmune thyroiditis (P < 0.05). Significant decreases in IgG1 and IgG3 levels were noted in subclinical autoimmune thyroiditis group at 6 months post-supplementation (P < 0.05). IgG1 levels in overt hypothyroidism decreased significantly compared with those at pre-supplementation (P < 0.05). In all patients with supplementation (n = 77), the TPOAb levels decreased in 52 at 6 months while increase or no change occurred in 25. The positive percentage and concentrations of IgG1 in patients whose TPOAb levels decreased at 6 months post-supplementation were markedly higher than those whose TPOAb levels increased (P < 0.05)., Conclusion: Se is effective in reducing TPOAb concentrations and the predominant decreasing TPOAb IgG subclasses are IgG1 and IgG3. And a high level of IgG1 subclass may explain the difficult decline of TPOAb.

Serum antibodies to different gangliosides have been identified in some Guillain-Barré (GBS) subtypes and variants. In the January issue of Experimental Neurology Susuki and colleagues (2012) showed that in experimental neuropathies associated with antibodies to GM1, GD1a and GD1b the common mechanism is a complement mediated dysfunction and disruption of the nodes of Ranvier which causes a pathophysiological continuum from early reversible conduction failure to axonal degeneration. These observations, correlated and integrated with electrophysiological and pathological findings in humans indicate that the GBS subtypes acute motor conduction block neuropathy, acute motor axonal neuropathy, acute motor and sensory neuropathy and acute sensory neuropathy and possibly also a chronic disorder as multifocal motor neuropathy represent a spectrum of the same immunopathologic process. Being the nodal axolemma and the paranode the focus of the nerve injury, these immune mediated neuropathies could be more properly classified as nodo-paranodopathies., (Copyright © 2012 Elsevier Inc. All rights reserved.)

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., (Copyright © 2012 Wiley Periodicals, Inc.)

Antibody networks have been studied in the past based on the connectivity between idiotypes and anti-idiotypes-antibodies that bind one another. Here we call attention to a different network of antibodies, antibodies connected by their reactivities to sets of antigens-the antigen-reactivity network. The recent development of antigen microarray chip technology for detecting global patterns of antibody reactivities makes it possible to study the immune system quantitatively using network analysis tools. Here, we review the analyses of IgM and IgG autoantibody reactivities of sera of mothers and their offspring (umbilical cords) to 300 defined self-antigens; the autoantibody reactivities present in cord blood represent the natural autoimmune repertories with which healthy humans begin life and the mothers' reactivities reflect the development of the repertoires in healthy young adults. Comparing the cord and maternal reactivities using several analytic tools led to the following conclusions: (1) The IgG repertoires showed a high correlation between each mother and her newborn; the IgM repertoires of all the cords were very similar and each cord differed from its mother's IgM repertoire. Thus, different humans are born with very similar IgM autoantibodies produced in utero and with unique IgG autoantibodies found in their individual mothers. (2) Autoantibody repertoires appear to be structured into sets of reactivities that are organized into cliques-reactivities to particular antigens are correlated. (3) Autoantibody repertoires are organized as networks of reactivities in which certain key antigen reactivities dominate the network-the dominant antigen reactivities manifest a "causal" relationship to sets of other correlated reactivities. Thus, repertoires of autoantibodies in healthy subjects, the immunological homunculus, are structured in hierarchies of antigen reactivities.

Neurological dysfunction results from vascular, inflammatory, degenerative, neoplastic, metabolic or genetic causes. Of particular interest is a group of neurological symptoms thought to be linked to an underlying tumour, the so-called paraneoplastic syndromes. It is considered to be due to an attempt by the immune system to subjugate the growth of the tumour by triggering an antibody response against the neuronal antigens expressed by the neoplasm. The unfortunate consequence of this is an assault by the immune components on the nervous tissue, thereby rapidly precipitating a variety of neurological deficits. Every level of the nervous system is potentially vulnerable, with the disability being considered as irreversible due to the lack of regenerative capacity of the neurons. This phenomenon is rare, occurring at an approximate frequency of less than 1% of all tumours and often accompanied by the presence of specific high-titre autoantibodies in both the cerebrospinal fluid and blood. This group of antibodies are non-pathogenic markers for paraneoplastic neurological syndromes, which have expanded to almost 20 since the discovery, in 1986, of the first clinically relevant syndrome. More recently, a new generation of antineuronal antibodies against cell surface antigens, having a direct pathogenic role in causing the disease, has emerged to complement the existing repertoire. Neuronal antibodies are useful diagnostic markers of the brain disease and also, in some cases, may reveal an underlying malignancy, thus facilitating faster diagnosis and earlier treatment with consequently better prognosis.

Naturally occurring autoantibodies (NAbs) are typically polyreactive, bind with low affinity to a discrete set of autoantigens and are encoded by variable region genes in germline configuration. They differ from disease-associated autoantibodies (autoAb), which are mostly monoreactive, somatically mutated and of high affinities. Structure-function studies have shown that polyreactivity of NAbs relies on the somatically generated complementarity determining region, CDR3, of the heavy chain. This finding suggested that NAb-producing B cells were positively selected from the pre-immune B-cell repertoire. The biological significance of this selection remains, however, unclear. Data originating mainly from transgenic mice have shown that mature NAb-producing B cells are frequently ignorant toward their antigen, possibly due to their low affinity, though active tolerance mechanisms are not excluded. An important issue is whether NAb-producing B cells constitute the pool from which pathologic auto Ab emerge after autoantigen-driven maturation. We summarize results obtained in mouse models, showing that some infectious agents are able to induce an autoantigen-driven activation of certain NAb-producing B cells. However direct proof that selection by autoantigen may lead to somatic hypermutation are still lacking. Other data tend to suggest that pathologic auto Abs may derive from non-autoimmune B cells that have diversified by somatic hypermutation of their variable region genes.

Aims: Type 1 diabetes and autoimmune thyroiditis are common autoimmune diseases characterized by the presence of autoantibodies against tissue-specific components. Non-thyroid-specific autoantibodies are frequent in patients with autoimmune thyroiditis. The prevalence of Type 1 diabetes autoantibodies in patients with autoimmune thyroiditis is unknown., Methods: The prevalence of Type 1 diabetes autoantibodies (GAD and IA2) was analysed in 236 Sardinian children and adolescents with autoimmune thyroiditis. GAD and IA2 antibodies were measured at the time of the diagnosis of autoimmune thyroiditis and re-evaluated after 1 year in the children who were shown to be positive. Autoantibody prevalence was evaluated in 949 healthy age-matched controls., Results: The prevalence of GAD and/or IA2 antibodies was 8% in the children and adolescents with autoimmune thyroiditis and 4.1% in control subjects (P = 0.017). When Type 1 diabetes autoantibodies were separately analysed, the difference remained significant for IA2 (3.39% in autoimmune thyroiditis vs. 1.16% in control subjects, P = 0.012), but not for GAD (5.1% in autoimmune thyroiditis vs. 3.79% in control subjects, P = 0.367). Seven of 10 children with autoimmune thyroiditis and detectable Type 1 diabetes autoantibodies at the diagnosis remained positive after 1 year. In the course of 2 years of follow-up, two patients who were positive for Type 1 diabetes autoantibodies at the time of diagnosis of autoimmune thyroiditis developed diabetes., Conclusions: This is the first study reporting the prevalence of Type 1 diabetes autoantibodies in a selected cohort of genetically homogeneous children and adolescents with autoimmune thyroiditis. The main finding was that the prevalence of Type 1 diabetes autoantibodies and of newly diagnosed Type 1 diabetes in patients with autoimmune thyroiditis was significantly higher than that observed in the general paediatric population, suggesting that children with autoimmune thyroiditis are at increased risk of developing Type 1 diabetes., (© 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.)

Background: Heparin-induced thrombocytopenia (HIT) is a thromboembolic complication that can occur with unfractionated heparin (UFH) or low molecular weight heparin (LMWH). Our objective was to determine and compare the incidence of IgG-class HIT antibodies in patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) with different antithrombotic prophylaxis therapies and their contributions to the occurrence of venous thromboembolism (VTE)., Methods: A prospective observational study was performed for 374 Japanese patients undergoing THA or TKA to determine the incidence of VTE. IgG-class anti-PF4/heparin antibodies were measured using IgG-specific EIA before and after the operation., Results: In the clinical outcome, the incidence of symptomatic deep vein thrombosis (DVT) was 15.0% (56/374, TKA; 35, THA; 21) and pulmonary emboli (PE) were not observed. The total seroconversion incidence of IgG-class PF4/heparin antibodies was 19.8% (74/374). The seroconversion incidence of IgG-class PF4/heparin antibodies was higher in patients receiving UFH (32.7%) compared to those receiving LMWH (9.5%) or fondaparinux (14.8%). Furthermore, the seroconversion incidence was significantly higher in patients undergoing TKA compared to those undergoing THA. Based on multivariate analysis, seroconversion of the IgG-class PF4/heparin antibodies was independent a risk factor for symptomatic DVT., Conclusion: Our findings show that the seroconversion of IgG-class anti-PF4/heparin antibodies differed with various anti-thrombotic prophylaxis therapeutics and was associated with the risk of DVT in a subset of patients undergoing total joint arthroplasty (TKA and THA).

Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disease, characterized by antibodies to type VII collagen (COL7). EBA can be induced in mice by immunization with a fragment of the non-collagenous 1 domain of murine COL7. Contrary to other autoimmune diseases, e.g., rheumatoid arthritis, little is known about the genetic susceptibility for EBA. We therefore used the EBA mouse model to address the hypothesis that disease induction depends on the major histocompatibility complex (MHC) haplotype. Mice from different inbred strains were immunized with recombinant murine COL7. Five distinct responses were observed: induction of (i) severe disease in SJL/J (H2s) and female MRL/MpJ (H2k), (ii) mild and transient disease in C57Bl/10.s (H2s), (iii) microscopic blistering in DBA/1J (H2q), (iv) only presence of non-pathogenic autoantibodies in C57Bl/6J (H2b), NZM2410/J (H2z), BXD2 (H2b), and male MRL/MpJ, and (v) complete resistance to EBA in NOD/ShiLtJ (H2g7) and C57Bl/10.q (H2q) mice. Overall, susceptibility to EBA was strongly associated with H2s. In addition, the diseased phenotype was associated with autoantibodies to specific regions of COL7. Our findings show that induction of antibodies with a distinct specificity is linked to the MHC haplotype in experimental EBA. Furthermore, our data are the basis for future studies with the goal of identifying non-MHC EBA susceptibility genes.

Paraneoplastic neurological syndromes can be associated with the presence of onconeural antibodies. These antibodies are the result of an immune response against a tumour that is ectopically expressing a neuronal antigen. The 'classical' onconeural antibodies (anti-Hu, Yo, Ma2, CRMP-5, amphiphysin and Ri) are directed against intracellular antigens and are strongly associated with underlying malignancy. By contrast, onconeural antibodies directed against cell surface antigens (eg, anti-NMDA, VGKC, AChR) have a weaker tumour association. This article gives a practical overview of the tumour associations, and the neurological associations, of the onconeural antibodies. There is also guidance on how to investigate occult malignancy in antibody positive cases.

Objective: To explore the role of IL-21 in the pathogenesis of myasthenia gravis (MG) and its influence on the the class switch of anti-AChR antibodies., Methods: Blood was taken from 26 patients and 18 healthy controls, and the expression of IL-21R mRNA in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR. The expression of IL-21R on B lymphocytes was measured by flow cytometry, while the concentrations of serum IL-21 and the levels of anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3) were tested by ELISA., Results: The serum concentration of IL-21 in the MG group was higher than that in the control group (31.686±8.499 pg/mL, 15.147±6.366 pg/mL) and the difference was significant (P<0.01). IL-21R mRNA expressed on PBMCs in the MG group was higher than that in the control group (0.139±0.052, 0.101±0.022), and the difference was significant (P<0.05). There was no difference between ocular MG and generalized MG subgroup (P>0.05). Compared with the control group, the expression of IL-21R on B lymphocytes also increased in the MG group (P<0.05). In the anti-AChR-Ab positive MG group, the serum concentration of IL-21 showed positive correlation with anti-AChR-IgG(P<0.05),but no correlation with its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05). Expression of IL-21R mRNA in the PBMCs showed no correlation with the level of serum anti-AChR-IgG and its isotype IgG(1), IgG(2), and IgG(3), respectively(P>0.05); however the expression of IL-21R in B lymphocytes showed positive correlation with anti-AChR-IgG and it's isotype IgG(1) and IgG(3) (P<0.05,P<0.01,P<0.05), but no correlation with IgG(2) (P>0.05)., Conclusion: IL-21 might induce the class switch of anti-AChR antibodies to IgG(1) and IgG(3) isotype through IL-21R on B lymphocytes which promotes the pathogenesis of the MG.