STAT4is a genetic risk factor for systemic sclerosis having additive effects withIRF5on disease susceptibility and related pulmonary fibrosis

Insights into the genetic landscape of systemic sclerosis

Systemic sclerosis (SSc) is a complex autoimmune disease that clinically manifests as progressive fibrosis of the skin and internal organs. Autoimmunity and endothelial dysfunction play important roles in the development of SSc but the causes of SSc remain unknown. Accumulating evidence, first from familial aggregation studies and subsequently from candidate gene association studies and genome wide association studies underscore the crucial contributions of genetics to the development of SSc. The identification of polymorphisms in the HLA region as well as non-HLA loci is important for understanding the risks of developing SSc but can also provide important pathogenic insight in SSc. While not translating into clinic practice yet, understanding the genetic landscape of SSc will hopefully assist in the diagnosis and management of patients with and/or at risk of developing SSc in the future. Herein we review the studies that investigate genetic risks of SSc susceptibility.

Immune mechanisms in fibrotic interstitial lung disease

Fibrotic interstitial lung diseases (fILDs) have poor survival rates and lack effective therapies. Despite evidence for immune mechanisms in lung fibrosis, immunotherapies have been unsuccessful for major types of fILD. Here, we review immunological mechanisms in lung fibrosis that have the potential to impact clinical practice. We first examine innate immunity, which is broadly involved across fILD subtypes. We illustrate how innate immunity in fILD involves a complex interplay of multiple cell subpopulations and molecular pathways. We then review the growing evidence for adaptive immunity in lung fibrosis to provoke a re-examination of its role in clinical fILD. We close with future directions to address key knowledge gaps in fILD pathobiology: (1) longitudinal studies emphasizing early-stage clinical disease, (2) immune mechanisms of acute exacerbations, and (3) next-generation immunophenotyping integrating spatial, genetic, and single-cell approaches. Advances in these areas are essential for the future of precision medicine and immunotherapy in fILD.

Immunogenetics of Systemic Sclerosis

Systemic sclerosis (SSc) is a rare autoimmune connective tissue disorder characterized by massive fibrosis, vascular damage, and immune imbalance. Advances in rheumatology and immunology over the past two decades have led to a redefinition of systemic sclerosis, shifting from its initial perception as primarily a "hyperfibrotic" state towards a recognition of systemic sclerosis as an immune-mediated disease. Consequently, the search for genetic markers has transitioned from focusing on fibrotic mechanisms to exploring immune regulatory pathways. Immunogenetics, an emerging field at the intersection of immunology, molecular biology, and genetics has provided valuable insights into inherited factors that influence immunity. Data from genetic studies conducted thus far indicate that alterations in genetic messages can significantly impact disease risk and progression. While certain genetic variations may confer protective effects, others may exacerbate disease susceptibility. This paper presents a comprehensive review of the most relevant genetic changes that influence both the risk and course of systemic sclerosis. Special emphasis is placed on factors regulating the immune response, recognizing their pivotal role in the pathogenesis of the disease.

Type I Interferons in Autoimmunity: Implications in Clinical Phenotypes and Treatment Response

Type I interferon (IFN-I) is thought to play a role in many systemic autoimmune diseases. IFN-I pathway activation is associated with pathogenic features, including the presence of autoantibodies and clinical phenotypes such as more severe disease with increased disease activity and damage. We will review the role and potential drivers of IFN-I dysregulation in 5 prototypic autoimmune diseases: systemic lupus erythematosus, dermatomyositis, rheumatoid arthritis, primary Sjögren syndrome, and systemic sclerosis. We will also discuss current therapeutic strategies that directly or indirectly target the IFN-I system.

Type I Interferons in Autoimmunity

Dysregulated IFN-1 responses play crucial roles in the development of multiple forms of autoimmunity. Many patients with lupus, systemic sclerosis, Sjogren's syndrome, and dermatomyositis demonstrate enhanced IFN-1 signaling. IFN-1 excess is associated with disease severity and autoantibodies and could potentially predict response to newer therapies targeting IFN-1 pathways. In this review, we provide an overview of the signaling pathway and immune functions of IFN-1s in health and disease. We also review the systemic autoimmune diseases classically associated with IFN-1 upregulation and current therapeutic strategies targeting the IFN-1 system.

Cellular and Molecular Diversity in Scleroderma

With the increasing armamentarium of high-throughput tools available at manageable cost, it is attractive and informative to determine the molecular underpinnings of patient heterogeneity in systemic sclerosis (SSc). Given the highly variable clinical outcomes of patients labelled with the same diagnosis, unravelling the cellular and molecular basis of disease heterogeneity will be crucial to predicting disease risk, stratifying management and ultimately informing a patient-centered precision medicine approach. Herein, we summarise the findings of the past several years in the fields of genomics, transcriptomics, and proteomics that contribute to unraveling the cellular and molecular heterogeneity of SSc. Expansion of these findings and their routine integration with quantitative analysis of histopathology and imaging studies into clinical care promise to inform a scientifically driven patient-centred personalized medicine approach to SSc in the near future.

Dysregulation of Type 1 Interferon Signaling in Systemic Sclerosis: a Promising Therapeutic Target?

Purpose of review

There are several lines of evidence at the genetic and gene expression levels linking type I interferon (IFN) activation to systemic sclerosis (SSc) pathogenesis. Herein, we summarize the potential role of type I IFN signaling components as therapeutic targets.

Recent findings

All type I IFN cytokines signal through the interferon-α/β receptor (IFNAR). Early phase studies indicate that anifrolumab (a human monoclonal antibody against IFNAR subunit 1) has an acceptable safety profile and can attenuate transforming growth factor beta (TGF-β)-mediated fibrosis in SSc skin, supporting its further clinical development. Janus kinase (JAK) signaling pathways are downstream from IFNAR. Building on their efficacy in hereditary interferonopathies, JAK inhibitors have the potential to block the deleterious IFN and other profibrotic cytokine activation in SSc and are promising drug targets. Moreover, interferon regulator factor (IRF) 5, 7, and 8 have been linked to the profibrotic response in SSc preclinical studies, underscoring their potential as therapeutic targets. Lastly, depletion of plasmacytoid dendritic cells (pDCs) attenuates the IFN activation and fibrotic response in vitro and murine model experiments and can be studied as a viable drug target in future clinical studies.

Summary

There is increasing evidence linking the prominent type I IFN activation to the observed exaggerated fibrotic response in SSc. Key components of type I IFN signaling are druggable therapeutic targets that can be pursued in future randomized clinical trials, in order to develop more effective therapeutic options for SSc.

Tofacitinib in the treatment of skin and musculoskeletal involvement in patients with systemic sclerosis, evaluated by ultrasound

Systemic sclerosis (SSc) is a rare autoimmune connective tissue disease characterized by fibrosis of the skin and internal organs, autoimmunity-driven damage and vasculopathy. The current approved disease-modifying treatments have limited efficacy, and treatment is guided toward alleviating organ complications. Thus, there is an unmet need for discovering new effective treatment options. There is recent evidence that the JAK/STAT signaling pathway is markedly activated in SSc patients. To assess the efficacy and safety of tofacitinib (TOF) on skin and musculoskeletal involvement as compared to methotrexate (MTX) in systemic sclerosis (SSc). In this 52-week pilot study, 66 patients with SSc were enrolled: 33 patients received 5 mg of oral TOF twice a day; 33 received 10 mg of MTX weekly. The proportion of dcSSc and lcSSc patients was similar (dcSSc: 42% TOF group and 36% MTX group; lcSSc: 58% TOF group and 64% MTX group). The primary outcome was the change in the modified Rodnan skin score (mRSS). Secondary outcomes included ultrasound (US) skin thickness and musculoskeletal involvement (US10SSc score). Digital ulcers (DUs) and adverse events (AEs) were documented through the treatment. Both groups had similar characteristics and medians on the outcome measures at baseline. At week 52, the TOF median mRSS was significantly lower than the MTX (p < 0.001) with a mean reduction of 13 points versus MTX 2.57. The mean percent improvement in the TOF group was 44% higher than in the MTX group. TOF median US skin thickness was significantly lower than MTX (p < 0.001), with a mean reduction of 0.31 mm versus 0.075 mm in the MTX group. The US10SSc median score was significantly lower in the TOF group (p = 0.002); mean reduction of 10.21 versus 5.27 in the MTX group. Healing of DUs with no new occurrences was observed in the TOF group. There was no significant difference between the groups in the number of AEs from baseline to week 52. TOF showed greater efficacy than MTX in reducing mRSS, skin thickness and musculoskeletal involvement in SSc and a satisfactory safety profile.

Type I interferon detection in autoimmune diseases: challenges and clinical applications

INTRODUCTION

Accumulating data highlights that the dysregulation of type I interferon (IFN) pathways plays a central role in the pathogenesis of several systemic and organ-specific autoimmune diseases. Advances in understanding the role of type I IFNs in these disorders can lead to targeted drug development as well as establishing potential disease biomarkers.

AREAS COVERED

Here, we summarize current knowledge regarding the role of type I IFNs in the major systemic, as well as organ-specific, autoimmune disorders, including prominent inflammatory CNS disorders like multiple sclerosis.

EXPERT OPINION

Type I IFN involvement and its clinical associations in a wide spectrum of autoimmune diseases represents a promising area for research aiming to unveil common pathogenetic pathways in systemic and organ-specific autoimmunity.

Assessing the association of rs7574865 STAT4 gene variant and type 1 diabetes mellitus among Egyptian patients

Background

Variants in the signal transducer and activator of transcription 4 (STAT4) gene have an important role in the incident of multiple autoimmune diseases including type 1 diabetes mellitus (T1D). It is a genetically related auto-immune disorder that resulted from T cell-mediated destruction of pancreatic cells that are in control for the production of insulin in the blood. The current study aimed to clarify the role of STAT4 (rs7574865) variant allelic and genotypic variations in the susceptibility to type 1 diabetes among Egyptians by using the real-time PCR.

Results

A total of 100 patients and 100 controls were genotyped for rs7574865, and the biochemical and anthropometric parameters were measured to show that type 1 diabetic patients had significantly higher levels of HbA1c and triglycerides compared to non-diabetic individuals (P < 0.05). And genetically, the T allele and GT genotype have a significant correlation with diabetes type 1.

Conclusion

It was confirmed by this study that the rs7574865 T allele and GT genotype have a significant correlation with diabetes type 1 incidence among Egyptian patients.

Updates on genetics in systemic sclerosis

Systemic sclerosis (SSc) is a complex disease, in which an interaction of genetic and environmental factors plays an important role in its development and pathogenesis. A number of genetic studies, including candidate gene analysis and genome-wide association study, have found that the associated genetic variants are mainly localized in noncoding regions in the expression quantitative trait locus and influence corresponding gene expression. The gene variants identified as a risk for SSc susceptibility include those associated with innate immunity, adaptive immune response, and cell death, while there are only few SSc-associated genes involved in the fibrotic process or vascular homeostasis. Human leukocyte antigen class II genes are associated with SSc-related autoantibodies rather than SSc itself. Since the pathways between the associated genotype and phenotype are still poorly understood, further investigations using multi-omics technologies are necessary to characterize the complex molecular architecture of SSc, identify biomarkers useful to predict future outcomes and treatment responses, and discover effective drug targets.

Systemic sclerosis pathogenesis: contribution of recent advances in genetics

PURPOSE OF REVIEW

To review susceptibility genes and how they could integrate in systemic sclerosis (SSc) pathophysiology providing insight and perspectives for innovative therapies.

RECENT FINDINGS

SSc is a rare disease characterized by vasculopathy, dysregulated immunity and fibrosis. Genome-Wide association studies and ImmunoChip studies performed in recent years revealed associated genetic variants mainly localized in noncoding regions and mostly affecting the immune system of SSc patients. Gene variants were described in innate immunity (IRF5, IRF7 and TLR2), T and B cells activation (CD247, TNFAIP3, STAT4 and BLK) and NF-κB pathway (TNFAIP3 and TNIP1) confirming previous biological data. In addition to impacting immune response, CSK, DDX6, DNASE1L3 and GSDMA/B could also act in the vascular and fibrotic components of SSc.

SUMMARY

Although genetic studies highlighted the dysregulated immune response in SSc, future research must focus on a deeper characterization of these variants with determination of their functional effects. Moreover, the role of these genes or others on specific vasculopathy and fibrosis would provide insight. Establishment of polygenic score or integrated genome approaches could identify new targets specific of SSc clinical features. This will allow physicians to propose new therapies to SSc patients.

Type I Interferons in Systemic Autoimmune Diseases: Distinguishing Between Afferent and Efferent Functions for Precision Medicine and Individualized Treatment

A sustained increase in type I interferon (IFN-I) may accompany clinical manifestations and disease activity in systemic autoimmune diseases (SADs). Despite the very frequent presence of IFN-I in SADs, clinical manifestations are extremely varied between and within SADs. The present short review will address the following key questions associated with high IFN-I in SADs in the perspective of precision medicine. 1) What are the mechanisms leading to high IFN-I? 2) What are the predisposing conditions favoring high IFN-I production? 3) What is the role of IFN-I in the development of distinct clinical manifestations within SADs? 4) Would therapeutic strategies targeting IFN-I be helpful in controlling or even preventing SADs? In answering these questions, we will underlie areas of incertitude and the intertwined role of autoantibodies, immune complexes, and neutrophils.

Classical Disease-Specific Autoantibodies in Systemic Sclerosis: Clinical Features, Gene Susceptibility, and Disease Stratification

Systemic sclerosis (SSc) is an autoimmune disease characterized by abnormalities in microcirculation, extracellular matrix accumulation, and immune activation. Autoantibodies are markers of immune abnormalities and provide diagnostic and predictive value in SSc. Anti-topoisomerase antibodies (ATAs), anticentromere antibodies (ACAs), and anti-RNA polymerase antibodies (ARAs) are the three classical specific antibodies with the highest availability and stability. In this review, we provide an overview of the recent progress in SSc research with respect to ATAs, ACAs, and ARAs, focusing on their application in distinguishing clinical phenotypes, such as malignancy and organ involvement, identifying genetic background in human leukocyte antigen (HLA) or non-HLA alleles, and their potential roles in disease pathogenesis based on the effects of antigen-antibody binding. We finally summarized the novel analysis using ATAs, ACAs, and ARAs on more detailed disease clusters. Considering these advantages, this review emphasizes that classical SSc-specific autoantibodies are still practical and have the potential for patient and risk stratification with applications in precise medicine for SSc.

Exome-Wide Association Analysis Suggests LRP2BP as a Susceptibility Gene for Endothelial Injury in Systemic Sclerosis in the Han Chinese Population

Genetic factors play a key role in the pathogenesis of autoimmune diseases, whereas the disease-causing variants remain largely unknown. Herein, we performed an exome-wide association study of systemic sclerosis in a Han Chinese population. In the discovery stage, 527 patients with systemic sclerosis and 5,024 controls were recruited and genotyped. In the validation study, an independent sample set of 479 patients and 1,096 controls were examined. In total, we found that four independent signals reached genome-wide significance. Among them, rs7574865 (P_combined = 3.87 × 10^-12) located within signal transducer and activator of transcription 4 gene was identified previously using samples of European ancestry. Additionally, another signal including three SNPs in linkage disequilibrium might be unreported susceptibility loci located in the epidermis differentiation complex region. Furthermore, two SNPs located within exon 3 of IGHM (rs45471499, P_combined = 1.15 × 10^-9) and upstream of LRP2BP (rs4317244, P_combined = 4.17 × 10^-8) were found. Moreover, rs4317244 was identified as an expression quantitative trait locus for LRP2BP that regulates tight junctions, cell cycle, and apoptosis in endothelial cell lines. Collectively, our results revealed three signals associated with systemic sclerosis in Han Chinese and suggested the importance of LRP2BP in systemic sclerosis pathogenesis. Given the limited sample size and discrepancies between previous results and our study, further studies in multiethnic populations are required for verification.

Genetics of systemic sclerosis

Systemic sclerosis is an autoimmune disease characterized by generalized fibrosis in connective tissues and internal organs as consequences of microvascular dysfunction and immune dysfunctions, which leads to premature death in affected individuals. The etiology of systemic sclerosis is complex and poorly understood, but as with most autoimmune diseases, it is widely accepted that both environmental and genetic factors contribute to disease risk. During the last decade, the number of genetic markers convincingly associated with systemic sclerosis has exponentially increased. In this article, we briefly mention the genetic components of systemic sclerosis. Then, we review the classical and novel genetic associations with systemic sclerosis, analyzing the firmest and replicated signals within non-human leukocyte antigen genes, identified by both candidate gene approach and genome-wide association studies. We also provide an insight into the future perspectives that will shed more light into the complex genetic background of the disease. Despite the remarkable advance of systemic sclerosis genetics during the last decade, the use of the new genetic technologies such as next-generation sequencing, as well as the deep phenotyping of the study cohorts, to fully characterize the genetic component of this disease is imperative to identify causal variants, which leads to more targeted and effective treatment of systemic sclerosis.

Identification and Validation of Key Genes Associated With Systemic Sclerosis-Related Pulmonary Hypertension

Systemic sclerosis-associated with pulmonary arterial hypertension (SSc-PAH) is still a major cause of SSc related deaths. Early diagnosis and prompt treatment are crucial to reduce the mortality of patients with SSc-PAH. To screen the candidate biomarkers and potential therapeutic targets for SSc-PAH, we analyzed the data set (GSE33463 and GSE19617) for confirming key genes in peripheral blood mononuclear cells from SSc-PAH patients. A total of 105 SSc patients from gene expression omnibus (GEO) were included as discovery cohort (n = 69) and duplication cohort (n = 36) for screening hub genes by weighted gene co-expression network analysis (WGCNA). Furthermore, an independent validation cohort (n = 40), including healthy controls, SSc and SSc-PAH patients, was used for further validation by quantitative real-time polymerase chain reaction. The results showed that four key genes, including IFIT2, IFIT3, RSAD2, and PARP14, may serve as potential biomarkers in SSc-PAH. Also, they could be independent risk factors for SSc-PAH. In conclusion, the four key genes can be expected to become the potential therapeutic targets and early biomarkers for accurate therapy and diagnosis of SSc-PAH in the future, which also provides promising insights into the pathogenesis of SSc-PAH at the molecular level.

The Roles of Immune Cells in the Pathogenesis of Fibrosis

Tissue injury and inflammatory response trigger the development of fibrosis in various diseases. It has been recognized that both innate and adaptive immune cells are important players with multifaceted functions in fibrogenesis. The activated immune cells produce various cytokines, modulate the differentiation and functions of myofibroblasts via diverse molecular mechanisms, and regulate fibrotic development. The immune cells exhibit differential functions during different stages of fibrotic diseases. In this review, we summarized recent advances in understanding the roles of immune cells in regulating fibrotic development and immune-based therapies in different disorders and discuss the underlying molecular mechanisms with a focus on mTOR and JAK-STAT signaling pathways.

Genetic Susceptibility to Systemic Sclerosis in the Greek-Cypriot Population: A Pilot Study

Background: Systemic Sclerosis (SSc), also known as scleroderma, is an autoimmune rheumatic disease, which is clinically subdivided into two major subgroups; limited (lcSSc) and diffuse cutaneous scleroderma (dcSSc). Even though the SSc etiologies remains unclear, some HLA and non-HLA genetic variants have been associated with the disease. Aim: This study was designed to evaluate the associations between several HLA-related genetic variants and SSc in the Greek-Cypriot population. Methods: Forty-one SSc patients and 164 controls were genotyped at 18 selected single nucleotide polymorphisms (SNPs) using restriction fragment length polymorphism analyses, Sanger sequencing, and a multiplex SNaPshot minisequencing assay. Logistic regression analysis under the log-additive model was used to evaluate all possible associations between these SNPs and SSc; nominal statistical significance was assumed at p < 0.05. Results: Associations of SSc with SNPs rs3117230, rs3128930, and rs3128965 within the HLA-DPB1 and HLA-DPB2 regions were observed in the Greek-Cypriot population at the level of p < 0.05. However, none of these associations survived a Bonferroni correction. The direction of the effect is consistent with the direction reported in previous studies. In addition, allele frequencies of the majority of the selected SNPs in the Greek-Cypriot population are similar to those reported in the European population. Conclusion: This study initiates the genetic investigation of SSc in the Greek-Cypriot population, a relatively small newly investigated population. Further investigation with a larger sample size and/or additional SSc susceptibility loci may confirm the association of some of these variants with SSc in the Greek-Cypriot population that could potentially be used for predictive testing.

Pathogenesis of systemic sclerosis associated interstitial lung disease

Systemic sclerosis is an autoimmune disease leading to vasculopathy and fibrosis of skin and internal organs. Despite likely shared pathogenic mechanisms, the patterns of skin and lung fibrosis differ. Pathogenesis of interstitial lung disease, a major cause of death in systemic sclerosis, reflects the intrinsic disease pathobiology and is associated with distinct clinical phenotypes and laboratory characteristics. The commonest histological pattern of systemic sclerosis–interstitial lung disease is non-specific interstitial pneumonia. Systemic sclerosis–interstitial lung disease pathogenesis involves multiple components, including susceptibility and triggering factors, which could be genetic or environmental. The process is amplified likely through ongoing inflammation and the link between inflammatory activity and fibrosis with IL6 emerging as a key mediator. The disease is driven by epithelial injury, reflected by markers in the serum, such as surfactant proteins and KL-6. In addition, mediators that are produced by epithelial cells and that regulate inflammatory cell trafficking may be important, especially CCL2. Other factors, such as CXCL4 and CCL18, point towards immune-mediated damage or injury response. Monocytes and alternatively activated macrophages appear to be important. Transforming growth factor beta appears central to pathogenesis and regulates epithelial repair and fibroblast activation. Understanding pathogenesis may help to unravel the stages of systemic sclerosis–interstitial lung disease, risks of progression and determinants of outcome. With this article, we set out to review the multiple factors, including genetic, environmental, cellular and molecular, that may be involved in the pathogenesis of systemic sclerosis–interstitial lung disease and the mechanisms leading to sustained fibrosis. We propose a model for the pathogenesis of systemic sclerosis–interstitial lung disease, based on the available literature.

Emerging targets of disease-modifying therapy for systemic sclerosis

Systemic sclerosis (SSc) has the highest cause-specific mortality of all the connective tissue diseases, and the aetiology of this complex and heterogeneous condition remains an enigma. Current disease-modifying therapies for SSc predominantly target inflammatory and vascular pathways but have variable and unpredictable clinical efficacy, and none is curative. Moreover, many of these therapies possess undesirable safety profiles and have no appreciable effect on long-term mortality. This Review describes the most promising of the existing therapeutic targets for SSc and places them in the context of our evolving understanding of the pathophysiology of this disease. As well as taking an in-depth look at the immune, inflammatory, vascular and fibrotic pathways implicated in the pathogenesis of SSc, this Review discusses emerging treatment targets and therapeutic strategies. The article concludes with an overview of important unanswered questions in SSc research that might inform the design of future studies of treatments aimed at modifying the course of this disease.

Novel insights into dendritic cells in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is a severe autoimmune fibrotic disease characterized by fibrosis, vasculopathy, and immune dysregulation. Dendritic cells (DCs) are the most potent antigen-presenting cells, specialized in pathogen sensing, with high capacity to shape the immune responses. The most recent technological advances have allowed the discovery of new DC subsets with potential implications in inflammatory conditions. Alterations of DC distribution in circulation and affected tissue as well as impaired DC function have been described in SSc patients, pointing towards a crucial role of these cells in SSc pathogenesis. In particular, recent studies have shown the importance of plasmacytoid DCs either by their high capacity to produce type I interferon or other inflammatory mediators implicated in SSc pathology, such as chemokine C-X-C motif ligand 4 (CXCL4). In-vivo models of SSc have been vital to clarify the implications of DCs in this disease, especially DCs depletion and specific gene knock-down studies. This review provides these new insights into the contribution of the different DCs subsets in the pathogenesis of SSc, as well as to the novel developments on DCs in in-vivo models of SSc and the potential use of DCs and their mediators as therapeutic targets.

The JAK/STAT pathway is activated in systemic sclerosis and is effectively targeted by tofacitinib

Rationale

Fibrosis leads to failure of the skin, lungs, and other organs in systemic sclerosis; accounts for substantial morbidity and mortality; and lacks effective therapy. Myofibroblast activation underlies organ fibrosis, but the key extracellular cues driving persistence of the process remain incompletely characterized.

Objectives

The objectives were to evaluate activation of the IL6/JAK/STAT axis associated with fibrosis in skin and lung biopsies from systemic sclerosis patients and effects of the Food and Drug Administration-approved JAK/STAT inhibitor, tofacitinib, on skin and lung fibrosis in animal models.

Methods

Bioinformatic analysis showed that IL6/JAK/STAT3 and tofacitinib gene signatures were aberrant in biopsies from systemic sclerosis patients in four independent cohorts. The results were confirmed by JAK and STAT3 phosphorylation in both skin and lung biopsies from patients with systemic sclerosis. Furthermore, treatment of mice with the selective JAK inhibitor tofacitinib not only prevented bleomycin-induced skin and lung fibrosis but also reduced skin fibrosis in TSK1/+ mice.

Conclusion

These findings implicate the JAK/STAT pathway in systemic sclerosis skin and lung fibrosis and identify tofacitinib as a potential antifibrotic agent for the treatment of systemic sclerosis and other fibrotic diseases.

Evaluation of the association between KIR polymorphisms and systemic sclerosis: a meta-analysis

BACKGROUND

The results of investigations on the association between killer cell immunoglobulin-like receptor (KIR) gene polymorphisms and the risk of systemic sclerosis (SSc) are inconsistent. To comprehensively evaluate the influence of KIR polymorphisms on the risk of SSc, this meta-analysis was performed.

METHODS

A systematic literature search was performed in electronic databases including Scopus and PubMed/MEDLINE to find all available studies involving KIR gene family polymorphisms and SSc risk prior to July 2019. Pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were measured to detect associations between KIR gene family polymorphisms and SSc risk.

RESULTS

Five articles, comprising 571 patients and 796 healthy participants, evaluating the KIR gene family polymorphisms were included in the final meta-analysis according to the inclusion and exclusion criteria, and 16 KIR genes were assessed. None of the KIR genes were significantly associated with the risk of SSc.

CONCLUSIONS

The current meta-analysis provides evidence that KIR genes might not be potential risk factors for SSc risk.

Defining genetic risk factors for scleroderma-associated interstitial lung disease : IRF5 and STAT4 gene variants are associated with scleroderma while STAT4 is protective against scleroderma-associated interstitial lung disease

Although several genetic associations with scleroderma (SSc) are defined, very little is known on genetic susceptibility to SSc-associated interstitial lung disease (SSc-ILD). A number of common polymorphisms have been associated with SSc-ILD, but most have not been replicated in separate populations. Four SNPs in IRF5, and one in each of STAT4, CD226 and IRAK1, selected as having been previously the most consistently associated with SSc-ILD, were genotyped in 612 SSc patients, of European descent, of whom 394 had ILD. The control population (n = 503) comprised individuals of European descent from the 1000 Genomes Project. After Bonferroni correction, two of the IRF5 SNPs, rs2004640 (OR (95% CI)1.30 (1.10–1.54), p^corr = 0.015) and rs10488631 (OR 1.48 (1.14–1.92), p^corr = 0.022), and the STAT4 SNP rs7574865 (OR 1.43 (1.18–1.73), p^corr = 0.0015) were significantly associated with SSc compared with controls. However, none of the SNPs were significantly different between patients with SSc-ILD and controls. Two SNPs in IRF5, rs10488631 (OR 1.72 (1.24–2.39), p^corr = 0.0098), and rs2004640 (OR 1.39 (1.11–1.75), p^corr = 0.03), showed a significant difference in allele frequency between controls and patients without ILD, as did STAT4 rs7574865 (OR 1.86 (1.45–2.38), p^corr = 6.6 × 10⁻⁶). A significant difference between SSc with and without ILD was only observed for STAT4 rs7574865, being less frequent in patients with ILD (OR 0.66 (0.51–0.85), p^corr = 0.0084). In conclusion, IRF5 rs2004640 and rs10488631, and STAT4 rs7574865 were significantly associated with SSc as a whole. Only STAT4 rs7574865 showed a significant difference in allele frequency in SSc-ILD, with the T allele being protective against ILD.

Key points • We confirm the associations of the IRF5 SNPs rs2004640 and rs10488631, and the STAT4 SNP rs7574865, with SSc as a whole. • None of the tested SNPs were risk factors for SSc-ILD specifically. • The STAT4 rs7574865 T allele was protective against the development of lung fibrosis in SSc patients. • Further work is required to understand the genetic basis of lung fibrosis in association with scleroderma.

Rationally-based therapeutic disease modification in systemic sclerosis: Novel strategies

Systemic sclerosis (SSc) is a highly challenging chronic condition that is dominated by the pathogenetic triad of vascular damage, immune dysregulation/autoimmunity and fibrosis in multiple organs. A hallmark of SSc is the remarkable degree of molecular and phenotypic disease heterogeneity, which surpasses that of other complex rheumatic diseases. Disease trajectories in SSc are unpredictable and variable from patient to patient. Disease-modifying therapies for SSc are lacking, long-term morbidity is considerable and mortality remains unacceptably high. Currently-used empirical approaches to disease modification have modest and variable clinical efficacy and impact on survival, are expensive and frequently associated with unfavorable side effects, and none can be considered curative. However, research during the past several years is yielding significant advances with therapeutic potential. In particular, the application of unbiased omics-based discovery technologies to large and well-characterized SSc patient cohorts, coupled with hypothesis-testing experimental research using a variety of model systems is revealing new insights into SSc that allow formulation of a more nuanced appreciation of disease heterogeneity, and a deepening understanding of pathogenesis. Indeed, we are now presented with numerous novel and rationally-based strategies for targeted SSc therapy, several of which are currently, or expected to be shortly, undergoing clinical evaluation. In this review, we discuss promising novel therapeutic targets and rationally-based approaches to disease modification that have the potential to improve long-term outcomes in SSc.

IMMUNOINFLAMMATORY RHEUMATIC DISEASES ASSOCIATED WITH TYPE I INTERFERON: NEW EVIDENCE

Immunoinflammatory rheumatic diseases (IIRDs) are a large group of pathological conditions with impaired immunological tolerance to autogenous tissues, leading to inflammation and irreversible organ damage. The review discusses current ideas on the role of type I interferons in the immunopathogenesis of IIRDs, primarily systemic lupus erythematosus, and new possibilities for personalized therapy.

Genetic aspects of idiopathic paediatric uveitis and juvenile idiopathic arthritis associated uveitis in Chinese Han

Background

Idiopathic paediatric uveitis (IPU) and juvenile idiopathic arthritis associated uveitis (JIA-U) are the two most common entities in paediatric uveitis. This study addressed the possible association of IPU and JIA-U with genes that had been shown earlier to be associated with juvenile idiopathic arthritis.

Methods

We carried out a case-control association study involving 286 IPU, 134 JIA-U patients and 743 healthy individuals. A total of 84 candidate single nucleotide polymorphisms (SNPs) in 60 genes were selected for this study. The MassARRAY platform and iPLEX Gold Genotyping Assay was used to genotype 83 candidate SNPs and the remaining SNP (rs27293) was analysed using the TaqMan SNP Genotyping Assay.

Results

No evidence was found for an association of the candidate polymorphisms tested with IPU. Six SNPs (PRM1/rs11074967, JAZF1/rs73300638, IRF5/rs2004640, MEFV/rs224217, PSMA3/rs2348071 and PTPN2/rs7234029) showed an association with JIA-U (p<1.0×10⁻²).

Conclusion

Our findings showed associations of six SNPs (PRM1/rs11074967, JAZF1/rs73300638, IRF5/rs2004640, MEFV/rs224217, PSMA3/rs2348071 and PTPN2/rs7234029) with JIA-U. No association was detected between the 84 tested SNPs and IPU.

Type I interferon dysregulation in Systemic Sclerosis

Systemic Sclerosis (Scleroderma, SSc) is a multifaceted disease characterized by autoimmunity, vasculopathy, and fibrosis affecting the skin and internal organs. Despite advances in the understanding and treatment of SSc in recent years, SSc continues to cause reduced quality of life and premature mortality. Type I interferons (IFNs), a family of cytokines with essential roles in the immune response to microbial infection, play a pathogenic role in certain autoimmune diseases (reviewed elsewhere in this edition). Polymorphisms in interferon-regulatory factors confer an increased risk of SSc, and IFN excess is evident in the blood and skin of a large percentage of SSc patients. Here we describe the evidence of Type I IFN dysregulation in SSc, revealed predominately by genetics and gene expression profiling. We also discuss evidence regarding mechanisms by which Type I IFN might contribute to SSc pathogenesis, mechanisms driving excess Type I IFN production in SSc, and the potential roles of Type I IFNs as biomarkers and therapeutic targets in SSc.

Lung Involvements in Rheumatic Diseases: Update on the Epidemiology, Pathogenesis, Clinical Features, and Treatment

Lung illness encountered in patients with rheumatic diseases bears clinical significance in terms of increased morbidity and mortality as well as potential challenges placed on patient care. Although our understanding of natural history of this important illness is still limited, epidemiologic knowledge has been accumulated during the past decade to provide useful information on the risk factors and prognosis of lung involvements in rheumatic diseases. Moreover, the pathogenesis particularly in the context of genetics has been greatly updated for both the underlying rheumatic disease and associated lung involvement. This review will focus on the current update on the epidemiologic and genetics features and treatment options of the lung involvements associated with four major rheumatic diseases (rheumatoid arthritis, systemic sclerosis, myositis, and systemic lupus erythematosus), with more attention to a specific form of involvement or interstitial lung disease.

Type I interferon in rheumatic diseases

The type I interferon pathway has been implicated in the pathogenesis of a number of rheumatic diseases, including systemic lupus erythematosus, Sjögren syndrome, myositis, systemic sclerosis, and rheumatoid arthritis. In normal immune responses, type I interferons have a critical role in the defence against viruses, yet in many rheumatic diseases, large subgroups of patients demonstrate persistent activation of the type I interferon pathway. Genetic variations in type I interferon-related genes are risk factors for some rheumatic diseases, and can explain some of the heterogeneity in type I interferon responses seen between patients within a given disease. Inappropriate activation of the immune response via Toll-like receptors and other nucleic acid sensors also contributes to the dysregulation of the type I interferon pathway in a number of rheumatic diseases. Theoretically, differences in type I interferon activity between patients might predict response to immune-based therapies, as has been demonstrated for rheumatoid arthritis. A number of type I interferon and type I interferon pathway blocking therapies are currently in clinical trials, the results of which are promising thus far. This Review provides an overview of the many ways in which the type I interferon system affects rheumatic diseases.

Genetic predictors of systemic sclerosis-associated interstitial lung disease: a review of recent literature

The interplay between genetic and environmental factors is likely involved in the pathogenesis of systemic sclerosis (SSc). Interstitial lung disease associated in the context of SSc (SSc-ILD) is associated with significant morbidity, and is the leading cause of death in SSc. The spectrum of SSc-ILD severity is wide, ranging from patients with only limited and inherently stable pulmonary involvement, to those with extensive and progressive pulmonary fibrosis. In order to provide accurate prognostic information for patients, and to initiate appropriate monitoring and treatment regimens, the ability to identify patients at risk of developing severe ILD early in the disease course is crucial. Identification of genetic variants involved in disease pathogenesis can not only potentially provide diagnostic/prognostic markers, but can also highlight dysregulated molecular pathways for therapeutic targeting. A number of genetic associations have been established for susceptibility to SSc, but far fewer studies have investigated genetic susceptibility to SSc-ILD specifically. In this review we present a summary of the studies assessing genetic associations with SSc-ILD.

Unfolding the pathogenesis of scleroderma through genomics and epigenomics

With unknown etiology, scleroderma (SSc) is a multifaceted disease characterized by immune activation, vascular complications, and excessive fibrosis in internal organs. Genetic studies, including candidate gene association studies, genome-wide association studies, and whole-exome sequencing have supported the notion that while genetic susceptibility to SSc appears to be modest, SSc patients are genetically predisposed to this disease. The strongest genetic association for SSc lies within the MHC region, with loci in HLA-DRB1, HLA-DQB1, HLA-DPB1, and HLA-DOA1 being the most replicated. The non-HLA genes associated with SSc are involved in various functions, with the most robust associations including genes for B and T cell activation and innate immunity. Other pathways include genes involved in extracellular matrix deposition, cytokines, and autophagy. Among these genes, IRF5, STAT4, and CD247 were replicated most frequently while SNPs rs35677470 in DNASE1L3, rs5029939 in TNFAIP3, and rs7574685 in STAT4 have the strongest associations with SSc. In addition to genetic predisposition, it became clear that environmental factors and epigenetic influences also contribute to the development of SSc. Epigenetics, which refers to studies that focus on heritable phenotypes resulting from changes in chromatin structure without affecting the DNA sequence, is one of the most rapidly expanding fields in biomedical research. Indeed extensive epigenetic changes have been described in SSc. Alteration in enzymes and mediators involved in DNA methylation and histone modification, as well as dysregulated non-coding RNA levels all contribute to fibrosis, immune dysregulation, and impaired angiogenesis in this disease. Genes that are affected by epigenetic dysregulation include ones involved in autoimmunity, T cell function and regulation, TGFβ pathway, Wnt pathway, extracellular matrix, and transcription factors governing fibrosis and angiogenesis. In this review, we provide a comprehensive overview of the current findings of SSc genetic susceptibility, followed by an extensive description and a systematic review of epigenetic research that has been carried out to date in SSc. We also summarize the therapeutic potential of drugs that affect epigenetic mechanisms, and outline the future prospective of genomics and epigenomics research in SSc.

The status of pulmonary fibrosis in systemic sclerosis is associated with IRF5, STAT4, IRAK1, and CTGF polymorphisms

Pulmonary fibrosis (PF) is one of the leading causes of death in systemic sclerosis (SSc) patients. Although all SSc patients are characterized by autoimmunity, only part of them suffer from PF, suggesting that beside autoimmunity, some additional factors are involved in the initiation of PF in SSc. In this study, we aimed to identify genetic polymorphisms associated with the status of PF in SSc. We performed that an exhaustive search of the PubMed database was performed to identify eligible studies. Then, a comprehensive meta-analysis was performed by comparing PF⁺-SSc and PF^--SSc patients to identify genetic polymorphisms associated with the status of PF in SSc. Among eight SSc-associated susceptibility polymorphisms which were applied for meta-analysis, IRF5 rs2004640 polymorphism (OR 1.12; 95% CI 1.02-1.22, P = 1.39 × 10^-2), STAT4 rs7574865 polymorphism (OR 1.25; 95% CI 1.07-1.47, P = 5.3 × 10^-3), IRAK1 rs1059702 polymorphism (OR 1.20; 95% CI 1.05-1.37, P = 0.007), and CTGF G-945C polymorphism (OR 1.42; 95% CI 1.18-1.71, P = 0.002) are associated with PF status in SSc, while TNFAIP3 rs5029939, CD226 rs763361, CD247 rs2056626, and IRF5 rs10488631 polymorphisms are not. Since IRF5, STAT4, and IRAK1 are important regulatory factors in the control of innate immune responses and CTGF is involved in the synthesis of extracellular matrix, these results suggest a role of the innate immunity and matrix compounds in the pathogenesis of PF in SSc.

Analysis of killer cell immunoglobulin-like receptors (KIRs) and their HLA ligand genes polymorphisms in Iranian patients with systemic sclerosis

Genetic factors have a great role in the pathogenesis of autoimmune diseases by cooperating with environmental stimuli. Killer immunoglobulin-like receptors (KIRs) are cell surface proteins on NK cells whose association with major histocompatibility complex-I regulates their killing function. The aim of this study was to provide information on the possible association between KIR and human leukocyte antigen (HLA) genes with systemic sclerosis disease in Iranian population. A total of 279 systemic sclerosis patients and 451 healthy controls were enrolled in this case-control study in order to determine the presence or absence of 19 KIR genes and 6 specific HLA class I ligands. DNA was analyzed by polymerase chain reaction using the specific sequence primer method (PCR-SSP). Among 11 discovered KIR genotypes, 6 genotypes showed a considerable role and 4 genotypes could preclude the risk of systemic sclerosis (SSc) disease. The gene-gene interactions were also analyzed, and significant confounding effects were seen between involved genes in these two combinations: "KIR3DL1; HLA-BW4-Thr80" and "KIR3DL1 -HLA-BW4-A1." None of single KIR genes showed significant effect on the risk of SSc. We conclude that there is an important relationship between KIR genes and their HLA ligands with incidence rate of systemic sclerosis in Iranian population. The powerful role of a number of discovered KIR/HLA compounds such as activating KIR genotype 3 and HLA-BW4-A1 confirmed the provocative hypothesis of the interplay between activating or inhibitory KIR genes with HLA ligands as a critical index of systemic sclerosis predisposition.

Genomic and genetic studies of systemic sclerosis: A systematic review

Systemic sclerosis is an autoimmune rheumatic disease characterised by fibrosis, vasculopathy and inflammation. The exact aetiology of SSc remains unknown but evidences show that various genetic factors may be involved. This review aimed to assess HLA alleles/non-HLA polymorphisms, microsatellites and chromosomal abnormalities that have thus far been associated with SSc. PubMed, Embase and Scopus databases were searched up to July 29, 2015 using a combination of search-terms. Articles retrieved were evaluated based on set exclusion and inclusion criteria. A total of 150 publications passed the filters. HLA and non-HLA studies showed that particular alleles in the HLA-DRB1, HLA-DQB1, HLA-DQA1, HLA-DPB1 genes and variants in STAT4, IRF5 and CD247 are frequently associated with SSc. Non-HLA genes analysis was performed using the PANTHER and STRING₁₀ databases. PANTHER classification revealed that inflammation mediated by chemokine and cytokine, interleukin and integrin signalling pathways are among the common extracted pathways associated with SSc. STRING₁₀ analysis showed that NFKB1, CSF3R, STAT4, IFNG, PRL and ILs are the main "hubs" of interaction network of the non-HLA genes associated with SSc. This study gathers data of valid genetic factors associated with SSc and discusses the possible interactions of implicated molecules.

The spectrum of orofacial manifestations in systemic sclerosis: a challenging management

Systemic sclerosis (SSc) is a rare multisystem connective tissue disorder characterized by the triad fibrosis, vasculopathy and immune dysregulation. This chronic disease has a significant impact on the orofacial region that is involved in more than two-thirds of the cases. SSc patients can show a wide array of oral manifestations, which are usually associated with a severe impairment of the quality of life. They often present a decreased the salivary flow and a reduced mouth opening that contribute substantially to the worsening of the oral health status. Therefore, SSc patients require specific and multidisciplinary interventions that should be initiated as early as possible. The identification of specific radiological and clinical signs at the early stage will improve the management of such patients. This study reviews the wide spectrum of orofacial manifestations associated with SSc and suggests clues for the oral management that remains challenging.

Genetics of systemic sclerosis: recent advances

Purpose of review

Large-scale and follow-up genetic association studies in systemic sclerosis (SSc) have implicated over 40 regions in disease risk, 15 of which with robust associations. Nevertheless, the causal variants and the functional mechanisms underlying the genetic associations remain elusive, and the reasons for the higher disease burden in African Americans unknown. Incorporating tools from diverse fields is beginning to unveil the role of genetic diversity and regulatory variation in SSc susceptibility. This review will summarize recent advances in SSc genetics, including autoimmune disease overlap, evidence of natural selection, and current progress towards the dissection of the functional role of associated risk variants.

Recent findings

In the past year, multiple large-scale studies reported novel strong and suggestive SSc associations. These results, coupled with the regions shared with other autoimmune diseases, emphasize the role of dysregulation of immune pathways as a key causative factor in SSc pathogenesis. Strong evidence implicates natural selection as a mechanism contributing to the maintenance of some of these SSc alleles in the population. Studies integrating genomic, transcriptomic, and epigenomic datasets in specific cell types to identify causal autoimmune disease variants are emerging.

Summary

The identification and comprehensive understanding of the factors and mechanisms contributing to SSc will contribute to improved diagnosis and disease management.

Genetic Susceptibility to Interstitial Lung Disease Associated with Systemic Sclerosis

Systemic sclerosis (SSc) is a connective tissue disease that is characterized by tissue fibrosis, microvasculopathy, and autoimmunity. Interstitial lung disease (ILD) is a common complication of SSc and is one of the frequent causes of mortality in SSc. Although the exact etiology of SSc remains unknown, clinical and experimental investigations have suggested that genetic and environmental factors are relevant to the pathogenesis of SSc and SSc-ILD. More than 30 genes have been identified as susceptibility loci for SSc, most of which are involved in immune regulation and inflammation. It is thought that the key pathogenesis of SSc-ILD is caused by the release of profibrotic mediators such as transforming growth factor β1 and connective tissue growth factor from lung cells induced by a persistent damage. This review presents the genetic susceptibility to SSc-ILD, including human leukocyte antigen and non-human leukocyte antigen genes, especially focusing on connective tissue growth factor.

Systemic sclerosis: An update in 2016

Systemic sclerosis (SSc) is a chronic immune disorder of unknown origin, dominated by excessive fibrosis responsible for cutaneous and pulmonary fibrosis, and by vascular endothelial dysfunction at the origin of skin ischemia, renal and pulmonary artery lesions. Renal and pulmonary complications are mainly responsible for the severity of the disease. Recent advances led to a better understanding of pathological mechanisms and a more accurate classification of patients according to clinical and biological (auto-antibodies) phenotype. Recent trials provided interesting data on different therapeutic strategies, depending on organ involvement. These data are of particular importance in such disease, still characterized by increased mortality and morbidity rates. In this review, we aim to synthetize recent advances in diagnosis and prognosis leading to better classification of SSc patients, and in therapeutic management.

Polymorphisms in STAT4 and IRF5 increase the risk of systemic sclerosis: a meta-analysis

BACKGROUND

Systemic sclerosis (SSc) is the most severe connective tissue disorder. Recent studies have demonstrated that genetic factors may play a role in the development of SSc. The aim of this study was to investigate the association of signal transducer and activator of transcription 4 (STAT4) rs7574865 and interferon regulatory factor 5 (IRF5) rs2004640 polymorphisms with risk of SSc.

METHODS

Case-control studies were obtained from the electronic database of PubMed, Medline, Embase, and CNKI (China National Knowledge Infrastructure) up to December 2013. The association between STAT4 and IRF5 polymorphisms and SSc susceptibility was assessed by pooled odds ratios (ORs) and 95% confidence intervals (CI).

RESULTS

Six related studies, including 4746 SSc cases and 7399 healthy controls, were pooled in this meta-analysis. For STAT4 polymorphism, we observed a statistically significant positive association between risk factor T allele carriers and SSc susceptibility (OR = 1.37, 95% CI = 1.27-1.48, P < 0.00001) in the overall population. The presence of limited cutaneous (lcSSc) and diffuse cutaneous (dcSSc) scleroderma also showed a significant association with each of the genetic models (P < 0.00001). For IRF5 polymorphism, the T allele was shown to be strongly associated with increased SSc risk (OR = 1.27, 95% CI = 1.17-1.39, P < 0.00001). No significant heterogeneity between studies was found.

CONCLUSIONS

The results demonstrated that STAT4 rs7574865 and IRF5 rs2004640G/T substitution are associated with a susceptibility to SSc, and they may serve as the SSc genetic susceptibility factor. These data confirmed that genetic polymorphisms may play a role in the development of SSc and have provided new insight into the pathogenesis of SSc.

Recent advances in the genetics of systemic sclerosis: toward biological and clinical significance

Significant advances have been made in understanding the genetic basis of systemic sclerosis (SSc) in recent years. Genomewide association and other large-scale genetic studies have identified 30 largely immunity-related genes which are significantly associated with SSc. We review these studies, along with genomewide expression studies, proteomic studies, genetic mouse models, and insights from rare sclerodermatous diseases. Collectively, these studies have begun to identify pathways that are relevant to SSc pathogenesis. The findings presented in this review illustrate how both genetic and genomic aberrations play important roles in the development of SSc. However, despite these recent discoveries, there remain major gaps between current knowledge of SSc, a unified understanding of pathogenesis, and effective treatment. To this aim, we address the important issue of SSc heterogeneity and discuss how future research needs to address this in order to develop a clearer understanding of this devastating and complex disease.

Germline variation of TNFAIP3 in primary Sjögren's syndrome-associated lymphoma

Background and objective

A germline and coding polymorphism (rs2230926) of TNFAIP3 (A20), a central gatekeeper of nuclear factor-kappa B (NF-kB) activation, was recently found associated with primary Sjögren's syndrome (pSS)-associated lymphoma in a French cohort. We aimed to replicate this association.

Patients and methods

The rs2230926 polymorphism was genotyped in cases and controls of European ancestry from two independent cohorts from UK and France. Case control association tests were performed (Fisher's test) in the two cohorts, followed by a meta-analysis of the two cohorts.

Results

The UK cohort included 308 controls and 590 patients with pSS including 31 with a history of lymphoma. The French cohort consisted of 448 controls and 589 patients with pSS including 47 with lymphoma. In both cohorts, the rs2230926 missense polymorphism was not associated with pSS. However, in the UK cohort, the rs2230926G variant was significantly associated with pSS-associated lymphoma (OR=2.74, 95% CI (1.07 to 7.03), p=0.0423, compared with patients with pSS without lymphoma, and OR=3.12, 95% CI (1.16 to 8.41), p=0.0314, compared with healthy controls) as observed in the French cohort. The meta-analysis of the two cohorts confirmed these results (OR=2.48, 95% CI (1.87 to 3.28) p=0.0037 and OR=2.60, 95% CI (1.91 to 3.53) p=0.0031, respectively).

Conclusions

This study confirms the role of A20 impairment in pSS-associated lymphoma. Subtle germline abnormalities of genes leading to impaired control of NF-kB activation in B cells continuously stimulated by autoimmunity enhance the risk of lymphoma.