Association of genes in the NF-κB pathway with antibody-positive primary Sjögren's syndrome.

Primary Sjögren's syndrome (SS) is a systemic autoimmune inflammatory disease characterized by focal lymphocytic infiltrates in the lachrymal and salivary glands and autoantibodies against the SSA/Ro and SSB/La antigens. Experimental studies have shown an activation of NF-κB in primary SS. NF-κB activation results in inflammation and autoimmunity and is regulated by inhibitory and activating proteins. Genetic studies have shown an association between multiple autoimmune diseases and TNFAIP3 (A20) and TNIP1 (ABIN1), both repressors of NF-κB and of IKBKE (IKKε), which is an NF-κB activator. The aim of this study was to analyse single nucleotide polymorphisms (SNPs) in the IKBKE, NFKB1, TNIP1 and TNFAIP3 genes for association with primary SS. A total of 12 SNPs were genotyped in 1105 patients from Scandinavia (Sweden and Norway, n = 684) and the UK (n = 421) and 4460 controls (Scandinavia, n = 1662, UK, n = 2798). When patients were stratified for the presence of anti-SSA and/or anti-SSB antibodies (n = 868), case-control meta-analysis found an association between antibody-positive primary SS and two SNPs in TNIP1 (P = 3.4 × 10(-5) , OR = 1.33, 95%CI: 1.16-1.52 for rs3792783 and P = 1.3 × 10(-3) , OR = 1.21, 95%CI: 1.08-1.36 for rs7708392). A TNIP1 risk haplotype was associated with antibody-positive primary SS (P = 5.7 × 10(-3) , OR = 1.47, 95%CI: 1.12-1.92). There were no significant associations with IKBKE, NFKB1 or TNFAIP3 in the meta-analysis of the Scandinavian and UK cohorts. We conclude that polymorphisms in TNIP1 are associated with antibody-positive primary SS.

Symptom-based stratification of patients with primary Sjögren's syndrome: multi-dimensional characterisation of international observational cohorts and reanalyses of randomised clinical trials.

BACKGROUND: Heterogeneity is a major obstacle to developing effective treatments for patients with primary Sjögren's syndrome. We aimed to develop a robust method for stratification, exploiting heterogeneity in patient-reported symptoms, and to relate these differences to pathobiology and therapeutic response. METHODS: We did hierarchical cluster analysis using five common symptoms associated with primary Sjögren's syndrome (pain, fatigue, dryness, anxiety, and depression), followed by multinomial logistic regression to identify subgroups in the UK Primary Sjögren's Syndrome Registry (UKPSSR). We assessed clinical and biological differences between these subgroups, including transcriptional differences in peripheral blood. Patients from two independent validation cohorts in Norway and France were used to confirm patient stratification. Data from two phase 3 clinical trials were similarly stratified to assess the differences between subgroups in treatment response to hydroxychloroquine and rituximab. FINDINGS: In the UKPSSR cohort (n=608), we identified four subgroups: Low symptom burden (LSB), high symptom burden (HSB), dryness dominant with fatigue (DDF), and pain dominant with fatigue (PDF). Significant differences in peripheral blood lymphocyte counts, anti-SSA and anti-SSB antibody positivity, as well as serum IgG, κ-free light chain, ß2-microglobulin, and CXCL13 concentrations were observed between these subgroups, along with differentially expressed transcriptomic modules in peripheral blood. Similar findings were observed in the independent validation cohorts (n=396). Reanalysis of trial data stratifying patients into these subgroups suggested a treatment effect with hydroxychloroquine in the HSB subgroup and with rituximab in the DDF subgroup compared with placebo. INTERPRETATION: Stratification on the basis of patient-reported symptoms of patients with primary Sjögren's syndrome revealed distinct pathobiological endotypes with distinct responses to immunomodulatory treatments. Our data have important implications for clinical management, trial design, and therapeutic development. Similar stratification approaches might be useful for patients with other chronic immune-mediated diseases. FUNDING: UK Medical Research Council, British Sjogren's Syndrome Association, French Ministry of Health, Arthritis Research UK, Foundation for Research in Rheumatology. VIDEO ABSTRACT.

Risk of non-Hodgkin's lymphoma in primary Sjögren's syndrome: a population-based study.

OBJECTIVE: Primary Sjögren's syndrome (SS) is associated with an increased risk of non-Hodgkin's lymphoma (NHL), but the reported prevalence and risk vary considerably. The objective of this study was to determine the risk of NHL in a well-defined population-based primary SS cohort in Norway. METHODS: The authors examined all patients fulfilling the American-European Consensus Group criteria for primary SS from 2 Norwegian counties and compared the data to the Cancer Registry of Norway to identify the primary SS patients who had lymphoma. In addition, lymphoma patient files from the same period were reviewed for undiagnosed primary SS to ensure the quality of registry data. RESULTS: As of July 1, 2009, 443 living subjects with primary SS were identified in an area with 896,840 inhabitants, which is 18.6% of the total population of Norway. Seven cases of NHL (1.6%) were found during a total followup of 3,813 person-years, resulting in a standardized incidence ratio of 9.0 (95% confidence interval 7.1-26.3) for NHL in primary SS patients. CONCLUSION: The risk of NHL in patients with primary SS in Norway is increased 9 times compared with the general population. This is in accordance with recent studies, and the quality and completeness of the registries and strict use of diagnostic criteria support the validity of the results.