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Objectives: Familial autoimmunity and polyautoimmunity represent extreme phenotypes ideal for identifying major genomic variants contributing to autoimmunity. Whole exome sequencing (WES) and linkage analysis are well suited for this purpose due to its strong resolution upon familial segregation patterns of functional protein coding and splice variants. The primary objective of this study was to identify potentially autoimmune causative variants using WES data from extreme pedigrees segregating polyautoimmunity phenotypes., Methods: DNA of 47 individuals across 10 extreme pedigrees, ascertained from probands affected with polyautoimmunity and familial autoimmunity, were selected for WES. Variant calls were obtained through Genome Analysis Toolkit. Filtration and prioritization framework to identify mutation(s) were applied, and later implemented for genetic linkage analysis. Sanger sequencing corroborated variants with significant linkage., Results: Novel and mostly rare variants harbored in SRA1, MLL4, ABCB8, DHX34 and PLAUR showed significant linkage (LOD scores are >3.0). The strongest signal was in SRA1, with a LOD score of 5.48. Network analyses indicated that SRA1, PLAUR and ABCB8 contribute to regulation of apoptotic processes., Conclusions: Novel and rare variants in genetic linkage with polyautoimmunity were identified throughout WES. Genes harboring these variants might be major players of autoimmunity., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A large number of autoimmune diseases (ADs) are more prevalent in women. The more frequent the AD and the later it appears, the more women are affected. Many ideas mainly based on hormonal and genetic factors that influence the autoimmune systems of females and males differently, have been proposed to explain this predominance. These hypotheses have gained credence mostly because many of these diseases appear or fluctuate when there are hormonal changes such as in late adolescence and pregnancy. Differences in X chromosome characteristics between men and women with an AD have led researchers to think that the genetic background of this group of diseases also relates to the genetic determinants of gender. These hormonal changes as well as the genetic factors that could explain why women are more prone to develop ADs are herein reviewed., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: Since characterization of the extent to which particular combinations of autoimmune diseases (ADs) occur in excess of that expected by chance may offer new insights into possible common pathophysiological mechanisms, polyautoimmunity (i.e., ADs co-occurring within patients) in systemic lupus erythematosus (SLE) and its associated factors were investigated., Methods: This was a cross-sectional study in which 335 consecutive patients with SLE and the history of 22 ADs were investigated. A multivariate analysis was performed. A systematic literature review was done and results were grouped by hierarchical cluster procedure analysis., Results: There were 136 (41%) SLE patients presenting with at least one other AD. A total of 191 ADs were observed, of which the most frequent were autoimmune thyroid disease (AITD), antiphospholipid syndrome (APS) and Sjögren's syndrome (SS), registered in 60 (18%), 48 (14%) and 47 (14%) cases, respectively. Out of a total number of 1515 SLE patients with polyautoimmunity (1379 reported previously and 136 informed here) there were 77 (5.1%) cases with multiple autoimmune syndrome (i.e., two or more ADs in addition to SLE). Female gender, articular involvement, familial autoimmunity, anti-Ro positivity and patient's origin were risk factors for polyautoimmunity while the presence of anti-RNP antibodies was protective. Four clusters of ADs were found. The most hierarchical one was composed of AITD, APS, SS, and systemic sclerosis., Conclusion: Polyautoimmunity is frequent in SLE, and it is influenced by clinical and immunological features. These findings support that clinically different autoimmune phenotypes might share common susceptibility variants., (Copyright 2009 Elsevier B.V. All rights reserved.)

The objective of this study was to analyze epidemiological tendencies of systemic sclerosis (SSc) around the world in order to identify possible local variations in the presentation and occurrence of the disease. A systematic review of the literature was performed through electronic databases using the keywords "Systemic Sclerosis" and "Clinical Characteristics." Out of a total of 167 articles, 41 were included in the analysis. Significant differences in the mean age at the time of diagnosis, subsets of SSc, clinical characteristics, and presence of antibodies were found between different regions of the word. Because variations in both additive and nonadditive genetic factors and the environmental variance are specific to the investigated population, ethnicity and geography are important characteristics to be considered in the study of SSc and other autoimmune diseases.

Characterization of the extent to which particular combinations of autoimmune diseases occur in excess of that expected by chance may offer new insights into possible common pathophysiological mechanisms. The goal of this study was to investigate the spectrum of polyautoimmunity (i.e. autoimmune diseases co-occurring within patients) and familial autoimmunity (i.e. diverse autoimmune diseases co-occurring within families) in patients with systemic sclerosis (SSc). A cross-sectional study of two convenience samples of patients with SSc, one in Canada and the other in Colombia, was performed. History of other autoimmune diseases in the SSc patients as well as a family history of autoimmunity was obtained. Of 719 patients, 273 (38%) had at least one other autoimmune disease. A total of 366 autoimmune diseases were reported, of which the most frequent were autoimmune thyroid disease (AITD, 38%), rheumatoid arthritis (RA, 21%), Sjögren's syndrome (18%), and primary biliary cirrhosis (4%). There were 260 (36%) patients with first-degree relatives with at least one autoimmune disease, of which the most frequent were RA (18%) and AITD (9%). Having at least one first-degree relative with autoimmune disease was a significant predictor of polyautoimmunity in SSc patients. No significant differences in polyautoimmunity or familial autoimmunity were noted between diffuse and limited subsets of disease. Our results indicate that polyautoimmunity is frequent in patients with SSc and autoimmune diseases cluster within families of these patients. Clinically different autoimmune phenotypes might share common susceptibility variants, which acting in epistatic pleiotropy may represent risk factors for autoimmunity.

Objectives To determine the prevalence and the predictive factors of autoimmune hypothyroidism (AH) within a systemic lupus erythematosus (SLE) cohort and to analyse the current information concerning the prevalence and impact of autoimmune thyroid disease (AITD) and thyroid autoimmunity in patients with SLE. Methods A total of 376 patients with SLE were assessed for the presence of the following: (i) confirmed AH, (ii) positive thyroperoxidase/thyroglobulin antibodies [TPOAb/TgAb] without hypothyroidism, (iii) nonautoimmune hypothyroidism and (iv) SLE patients with neither. Multivariate analysis and a classification and regression tree model were used to analyse data. The current information was discussed through a systematic literature review (SLR). Results In our cohort, the prevalence of confirmed AH was 12%. However, in euthyroid patients with SLE, TPOAb and TgAb were observed in 21% and 10%, respectively. Patients with confirmed AH were significantly older and had later age at onset of the disease. Smoking (adjusted odds ratio (AOR) 6-93, 95% CI 1.98 28-54, P = 0-004), Sjógren's Syndrome (SS) (AOR 23-2, 95% CI 1-89 359-53, P = 0-015) and positivity for anticyclic citrullinated peptide (anti-CCP) (AOR 10-35, 95% CI 1-04 121-26, P = 0-047) were associated with AH-SLE, regardless of gender and duration of the disease. Smoking and SS were confirmed as predictors of AH-SLE. In the SLR, the prevalence of AITD ranged from 1% to 60%. The factors associated with this polyautoimmunity were female gender, older age, smoking, certain autoantibodies, SS, and cutaneous and articular involvement. Conclusions AITD is frequent in SLE and does not affect the severity of SLE. Identified risk factors will assist clinicians in the search for AITD. Our results encourage smoke-free policies in patients with SLE. [ABSTRACT FROM AUTHOR]

Background: Multiple autoimmune syndrome (MAS), an extreme phenotype of autoimmune disorders, is a very well suited trait to tackle genomic variants of these conditions. Whole exome sequencing (WES) is a widely used strategy for detection of protein coding and splicing variants associated with inherited diseases. Methods: The DNA of eight patients affected by MAS [all of whom presenting with Sjögren's syndrome (SS)], four patients affected by SS alone and 38 unaffected individuals, were subject to WES. Filters to identify novel and rare functional (pathogenic-deleterious) homozygous and/or compound heterozygous variants in these patients and controls were applied. Bioinformatics tools such as the Human gene connectome as well as pathway and network analysis were applied to test overrepresentation of genes harbouring these variants in critical pathways and networks involved in autoimmunity. Results: Eleven novel and rare functional variants were identified in cases but not in controls, harboured in: MACF1, KIAA0754, DUSP12, ICA1, CELA1, LRP1/STAT6, GRIN3B, ANKLE1, TMEM161A, and FKRP. These were subsequently subject to network analysis and their functional relatedness to genes already associated with autoimmunity was evaluated. Notably, the LRP1/STAT6 novel mutation was homozygous in one MAS affected patient and heterozygous in another. LRP1/STAT6 disclosed the strongest plausibility for autoimmunity. LRP1/STAT6 are involved in extracellular and intracellular anti-inflammatory pathways that play key roles in maintaining the homeostasis of the immune system. Further; networks, pathways, and interaction analyses showed that LRP1 is functionally related to the HLA-B and IL10 genes and it has a substantial impact within immunological pathways and/or reaction to bacterial and other foreign proteins (phagocytosis, regulation of phospholipase A2 activity, negative regulation of apoptosis and response to lipopolysaccharides). Further, ICA1 and STAT6 were also closely related to AIRE and IRF5, two very well known autoimmunity genes. Conclusions: Novel and rare exonic mutations that may account for autoimmunity were identified. Among those, the LRP1/STAT6 novel mutation has the strongest case for being categorised as potentially causative of MAS given the presence of intriguing patterns of functional interaction with other major genes shaping autoimmunity. [ABSTRACT FROM AUTHOR]

Background: A primary characteristic of complex genetic diseases is that affected individuals tend to cluster in families (that is, familial aggregation). Aggregation of the same autoimmune condition, also referred to as familial autoimmune disease, has been extensively evaluated. However, aggregation of diverse autoimmune diseases, also known as familial autoimmunity, has been overlooked. Therefore, a systematic review and meta-analysis were performed aimed at gathering evidence about this topic. Methods: Familial autoimmunity was investigated in five major autoimmune diseases, namely, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid disease, multiple sclerosis and type 1 diabetes mellitus. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed. Articles were searched in Pubmed and Embase databases. Results: Out of a total of 61 articles, 44 were selected for final analysis. Familial autoimmunity was found in all the autoimmune diseases investigated. Aggregation of autoimmune thyroid disease, followed by systemic lupus erythematosus and rheumatoid arthritis, was the most encountered. Conclusions: Familial autoimmunity is a frequently seen condition. Further study of familial autoimmunity will help to decipher the common mechanisms of autoimmunity. [ABSTRACT FROM AUTHOR]

Background: Genetic and epigenetic factors interacting with the environment over time are the main causes of complex diseases such as autoimmune diseases (ADs). Among the environmental factors are organic solvents (OSs), which are chemical compounds used routinely in commercial industries. Since controversy exists over whether ADs are caused by OSs, a systematic review and meta-analysis were performed to assess the association between OSs and ADs. Methods and Findings: The systematic search was done in the PubMed, SCOPUS, SciELO and LILACS databases up to February 2012. Any type of study that used accepted classification criteria for ADs and had information about exposure to OSs was selected. Out of a total of 103 articles retrieved, 33 were finally included in the meta-analysis. The final odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by the random effect model. A sensitivity analysis confirmed results were not sensitive to restrictions on the data included. Publication bias was trivial. Exposure to OSs was associated to systemic sclerosis, primary systemic vasculitis and multiple sclerosis individually and also to all the ADs evaluated and taken together as a single trait (OR: 1.54; 95% CI: 1.25-1.92; p-value<0.001). Conclusion: Exposure to OSs is a risk factor for developing ADs. As a corollary, individuals with non-modifiable risk factors (i.e., familial autoimmunity or carrying genetic factors) should avoid any exposure to OSs in order to avoid increasing their risk of ADs. [ABSTRACT FROM AUTHOR]

Abstract: Conclusions from association studies could be spurious because of population stratification; therefore we combined association with family studies seeking to confirm which human leukocyte antigen (HLA) class II alleles/haplotypes were associated with type 1 diabetes (T1D) in the admixed Latin America. By calculating the effect summary odds ratios (OR) and their 95% confidence intervals (95% CI), data up to June 2010 showed that risk associations were observed with DRB1*0301-DQA1*0501-DQB1*0201 (odds ratio [OR]: 7.51; 95% confidence interval [CI]: 3.69–15.25) and DQB1*0302 in presence of DRB1*0405 (OR: 11.64; 95% CI: 3.15–43.01) or DRB1*0401 (OR: 5.85; 95% CI: 3.07–11.14). In contrast, DRB1*0404-DQB1*0302 had a nonsignificant TID risk (OR: 2.23; 95% CI: 0.91–5.43). T1D protective associations were observed with DRB1*11-DQA1*0501-DQB1*0301 (OR: 0.24; 95% CI: 0.1–0.56) and DRB1*15-DQA1*0102-DQB1*0602 (OR: 0.35; 95% CI: 0.17–0.73). These results were similar to those observed in Caucasian and other populations, thus highlighting the primary role of class II HLA in T1D regardless of ethnicity. A DRB1*04 risk hierarchy was confirmed with the DRB1*0405 being in the top. A binding prediction analysis disclosed possible receptor–ligand interactions in the HLA–antigenic peptide complex. [Copyright &y& Elsevier]

Objectives. Recently, a non-synonymous (Gly307Ser) variant, rs763361, in the CD226 gene was shown to be associated with multiple autoimmune diseases (ADs) in European Caucasian populations. However, shared autoimmunity with CD226 has not been evaluated in non-European populations. The aim of the present study is to assess the association of this single nucleotide polymorphism (SNP) with ADs in non-European populations. [ABSTRACT FROM PUBLISHER]

Three related lines of evidence sustain the common origin for autoimmune diseases (ADs). First, the clinical evidence corresponding to the kaleidoscope of autoimmunity, which is the co-occurrence of various ADs within an individual or co-occurrence within members of a nuclear family. Second, the physiopathologic evidence indicating that the pathologic mechanisms might be similar among ADs. Last, the genetic evidence indicating that autoimmune phenotypes could represent pleiotropic outcomes of nonspecific disease genes. The two conditions that better illustrate the kaleidoscope of autoimmunity are multiple autoimmune syndromes and familial autoimmunity. The multiple autoimmune syndromes consist of the presence of three or more well-defined autoimmune conditions in a single patient. The familial autoimmunity is defined as the presence of diverse ADs on multiple members of a nuclear family. Herein, both the multiple autoimmune syndromes and familial autoimmunity are discussed and various epidemiological factors considered in the context of the common genetic background of autoimmunity. [ABSTRACT FROM AUTHOR]

Studies documenting increased risk of developing autoimmune diseases (ADs) have shown that these conditions share several immunogenetic mechanisms (i.e., the autoimmune tautology). This report explored familial aggregation and segregation of AD, polyautoimmunity, and multiple autoimmune syndrome (MAS) in 210 families. Familial aggregation was examined for first-degree relatives. Segregation analysis was implemented as in S.A.G.E. release 6.3. Data showed differences between late- and early-onset families regarding their age, age of onset, and sex. Familial aggregation of AD in late- and early-onset families was observed. For polyautoimmunity as a trait, only aggregation was observed between sibling pairs in late-onset families. No aggregation was observed for MAS. Segregation analyses for AD suggested major gene(s) with no clear discernible classical known Mendelian transmission in late-onset families, while for polyautoimmunity and MAS no model was implied. Data suggest that polyautoimmunity and MAS are not independent traits and that gender, age, and age of onset are interrelated factors influencing autoimmunity. [ABSTRACT FROM AUTHOR]

Abstract: The coexistence of autoimmune diseases (i.e., polyautoimmunity) in Sjögren’s syndrome (SS) was investigated in a cross-sectional study involving 410 patients. Logistic regression analysis and the Rogers and Tanimoto index were used to evaluate risk factors and clustering, respectively. There were 134 (32.6%) patients with polyautoimmunity. The most frequent and closer coexistent diseases were autoimmune thyroid disease (21.5%), rheumatoid arthritis (8.3%), systemic lupus erythematosus (7.6%), and inflammatory bowel disease (0.7%) which together constituted a cluster group. There were 35 (8.5%) patients with multiple autoimmune syndrome. Besides disease duration, a history of habitual smoking and spontaneous abortion were found to be risk factors for the developing of polyautoimmunity. This study discloses a high prevalence of polyautoimmunity in SS, its associated risk factors and the grouping pattern of such a condition. These results may serve to define plausible approaches to study the common mechanisms of autoimmune diseases. [Copyright &y& Elsevier]

Abstract: Background and aim: The involvement of Toll-like receptor (TLR)-mediated pathways in infectious and autoimmunity has been suggested. The MyD88 adaptor-like (Mal) protein, also known as the TIR domain-containing adaptor protein (TIRAP), is implicated in the TLR2- and TLR4-mediated MyD88-dependent signaling pathway. The aim of this study was to investigate the influence of the functional TIRAP (MAL) S180L polymorphism on tuberculosis (TB) and four autoimmune diseases namely: rheumatoid arthritis (RA), primary Sjögren''s syndrome (pSS), systemic lupus erythematosus (SLE) and type 1 diabetes mellitus (T1D). Methods: This was a case–control and family based association study in which 1325 individuals from a well-defined Colombian population were involved. TIRAP (MAL) S180L genotyping was done by using a polymerase chain reaction-restriction fragment length polymorphism technique and by direct sequencing. Results: Leu180 allele was found to be a protective factor against developing TB (odd ratio (OR): 0.53, 95% confidence interval (CI): 0.29–0.97) and SLE (OR: 0.29, 95% CI: 0.14–0.61) while no significant influence on RA, pSS and T1D was observed. Conclusion: These results support the influence of TIRAP (MAL) S180L polymorphism on TB and indicate that TB and SLE might share a common immunogenetic pathway in the innate immune response. [Copyright &y& Elsevier]