Genetic and clinical basis for two distinct subtypes of primary Sjögren's syndrome

Objectives Clinical presentation of primary Sjögren’s syndrome (pSS) varies considerably. A shortage of evidence-based objective markers hinders efficient drug development and most clinical trials have failed to reach primary endpoints. Methods We performed a multicentre study to identify patient subgroups based on clinical, immunological and genetic features. Targeted DNA sequencing of 1853 autoimmune-related loci was performed. After quality control, 918 patients with pSS, 1264 controls and 107 045 single nucleotide variants remained for analysis. Replication was performed in 177 patients with pSS and 7672 controls. Results We found strong signals of association with pSS in the HLA region. Principal component analysis of clinical data distinguished two patient subgroups defined by the presence of SSA/SSB antibodies. We observed an unprecedented high risk of pSS for an association in the HLA-DQA1 locus of odds ratio 6.10 (95% CI: 4.93, 7.54, P=2.2×10−62) in the SSA/SSB-positive subgroup, while absent in the antibody negative group. Three independent signals within the MHC were observed. The two most significant variants in MHC class I and II respectively, identified patients with a higher risk of hypergammaglobulinaemia, leukopenia, anaemia, purpura, major salivary gland swelling and lymphadenopathy. Replication confirmed the association with both MHC class I and II signals confined to SSA/SSB antibody positive pSS. Conclusion Two subgroups of patients with pSS with distinct clinical manifestations can be defined by the presence or absence of SSA/SSB antibodies and genetic markers in the HLA locus. These subgroups should be considered in clinical follow-up, drug development and trial outcomes, for the benefit of both subgroups.publishedVersio

Complement C4 Copy Number Variation is Linked to SSA/Ro and SSB/La Autoantibodies in Systemic Inflammatory Autoimmune Diseases

Objective Copy number variation of the C4 complement components, C4A and C4B, has been associated with systemic inflammatory autoimmune diseases. This study was undertaken to investigate whether C4 copy number variation is connected to the autoimmune repertoire in systemic lupus erythematosus (SLE), primary Sjögren's syndrome (SS), or myositis. Methods Using targeted DNA sequencing, we determined the copy number and genetic variants of C4 in 2,290 well-characterized Scandinavian patients with SLE, primary SS, or myositis and 1,251 healthy controls. Results A prominent relationship was observed between C4A copy number and the presence of SSA/SSB autoantibodies, which was shared between the 3 diseases. The strongest association was detected in patients with autoantibodies against both SSA and SSB and 0 C4A copies when compared to healthy controls (odds ratio [OR] 18.0 [95% confidence interval (95% CI) 10.2–33.3]), whereas a weaker association was seen in patients without SSA/SSB autoantibodies (OR 3.1 [95% CI 1.7–5.5]). The copy number of C4 correlated positively with C4 plasma levels. Further, a common loss-of-function variant in C4A leading to reduced plasma C4 was more prevalent in SLE patients with a low copy number of C4A. Functionally, we showed that absence of C4A reduced the individuals’ capacity to deposit C4b on immune complexes. Conclusion We show that a low C4A copy number is more strongly associated with the autoantibody repertoire than with the clinically defined disease entities. These findings may have implications for understanding the etiopathogenetic mechanisms of systemic inflammatory autoimmune diseases and for patient stratification when taking the genetic profile into account.publishedVersio

Genome-wide association study identifies Sjögren’s risk loci with functional implications in immune and glandular cells

Sjögren’s disease is a complex autoimmune disease with twelve established susceptibility loci. This genome-wide association study (GWAS) identifies ten novel genome-wide significant (GWS) regions in Sjögren’s cases of European ancestry: CD247, NAB1, PTTG1-MIR146A, PRDM1-ATG5, TNFAIP3, XKR6, MAPT-CRHR1, RPTOR-CHMP6-BAIAP6, TYK2, SYNGR1. Polygenic risk scores yield predictability (AUROC = 0.71) and relative risk of 12.08. Interrogation of bioinformatics databases refine the associations, define local regulatory networks of GWS SNPs from the 95% credible set, and expand the implicated gene list to >40. Many GWS SNPs are eQTLs for genes within topologically associated domains in immune cells and/or eQTLs in the main target tissue, salivary glands.Research reported in this publication was supported by the National Institutes of Health (NIH): R01AR073855 (C.J.L.), R01AR065953 (C.J.L.), R01AR074310 (A.D.F.), P50AR060804 (K.L.S.), R01AR050782 (K.L.S), R01DE018209 (K.L.S.), R33AR076803 (I.A.), R21AR079089 (I.A.); NIDCR Sjögren’s Syndrome Clinic and Salivary Disorders Unit were supported by NIDCR Division of Intramural Research at the National Institutes of Health funds - Z01-DE000704 (B.W.); Birmingham NIHR Biomedical Research Centre (S.J.B.); Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2155 – Projektnummer 390874280 (T.W.); Research Council of Norway (Oslo, Norway) – Grant 240421 (TR.R.), 316120 (M.W-H.); Western Norway Regional Health Authority (Helse Vest) – 911807, 912043 (R.O.); Swedish Research Council for Medicine and Health (L.R., G.N., M.W-H.); Swedish Rheumatism Association (L.R., G.N., M.W-H.); King Gustav V’s 80-year Foundation (G.N.); Swedish Society of Medicine (L.R., G.N., M.W-H.); Swedish Cancer Society (E.B.); Sjögren’s Syndrome Foundation (K.L.S.); Phileona Foundation (K.L.S.). The Stockholm County Council (M.W-H.); The Swedish Twin Registry is managed through the Swedish Research Council - Grant 2017-000641. The French ASSESS (Atteinte Systémique et Evolution des patients atteints de Syndrome de Sjögren primitive) was sponsored by Assistance Publique-Hôpitaux de Paris (Ministry of Health, PHRC 2006 P060228) and the French society of Rheumatology (X.M.).publishedVersio

Impacts of Home-Based Telework on Quality of Life for Employees and Their Partners. Quantitative and Qualitative Results From a European Survey

home-based telework, family, quality of life, satisfaction with life.,

Genetic associations to germinal centre formation in primary Sjogren's syndrome

Background Primary Sjogren's syndrome (pSS) is an autoimmune rheumatic disease mainly characterised by focal mononuclear cell infiltration in the salivary and lacrimal glands, and by the symptoms xerostomia and keratoconjunctivitis sicca. Germinal centre-like structures (GC) are found in the minor salivary glands of approximately 25% of patients. In this study, we aimed to assess genetic variations in pSS patients with GC-like formations (GC+) compared with patients without such formations (GC-). Methods Minor salivary gland biopsies from Swedish and Norwegian pSS patients (n=320) were evaluated for GC-like formations, identifying 76 GC+ and 244 GC-patients. A panel of 1536 single-nucleotide polymorphisms (SNPs) in 107 genes was genotyped. Minor allele frequencies in GC+ and GC- patients were compared using Fisher's exact test, and associations were considered significant when p<4.7x10(-4) and suggestive when p<0.01. Results In this case-only analysis, we identified two SNPs in CCL11 (eotaxin) associated with GC-like structures (p<4.7x10(-4), OR 0.45 and 0.41, respectively). A haplotype of the two minor alleles was associated with GC status with p=2.6x10(-4,) OR 0.40. Suggestive associations (p<0.01) were found in SNPs in the B cell activation and/or GC-formation related genes AICDA, BANK1 and BCL2. Furthermore, SNPs in IL17A, ICA1, PKN1 and SNPs in the NF-kappa B pathway genes CARD8, IKBKE and TANK were found suggestively associated with GC-like structures. Conclusions Our findings suggest that genetic variations may explain why ectopic GC-like structures are present in some pSS patients, and support the hypothesis that GC+ and GC- patients represent distinct disease phenotypes

DNA Methylation-Based Interferon Scores Associate With Sub-Phenotypes in Primary Sjögren's Syndrome

Primary Sjogren's syndrome (pSS) is an autoimmune inflammatory disease with profound clinical heterogeneity, where excessive activation of the type I interferon (IFN) system is considered one of the key mechanisms in disease pathogenesis. Here we present a DNA methylation-based IFN system activation score (DNAm IFN score) and investigate its potential associations with sub-phenotypes of pSS. The study comprised 100 Swedish patients with pSS and 587 Swedish controls. For replication, 48 patients with pSS from Stavanger, Norway, were included. IFN scores were calculated from DNA methylation levels at the IFN-induced genes RSAD2, IFIT1 and IFI44L. A high DNAm IFN score, defined as &gt; mean(controls) +2SD(controls) (IFN score &gt; 4.4), was observed in 59% of pSS patients and in 4% of controls (p=1.3x10(-35)). Patients with a high DNAm IFN score were on average seven years younger at symptom onset (p=0.017) and at diagnosis (p=3x10(-3)). The DNAm IFN score levels were significantly higher in pSS positive for both SSA and SSB antibodies compared to SSA/SSB negative patients (p(discovery)=1.9x10(-8), p(replication)=7.8x10(-4)). In patients positive for both SSA subtypes Ro52 and Ro60, an increased score was identified compared to single positive patients (p=0.022). Analyzing the discovery and replication cohorts together, elevated DNAm IFN scores were observed in pSS with hypergammaglobulinemia (p=2x10(-8)) and low C4 (p=1.5x10(-3)) compared to patients without these manifestations. Patients &lt; 70 years with ongoing lymphoma at DNA sampling or lymphoma at follow-up (n=7), presented an increased DNAm IFN score compared to pSS without lymphoma (p=0.025). In conclusion, the DNAm-based IFN score is a promising alternative to mRNA-based scores for identification of patients with activation of the IFN system and may be applied for patient stratification guiding treatment decisions, monitoring and inclusion in clinical trials

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Association between genetic variants in the tumour necrosis factor/lymphotoxi

Association between genetic variants in the tumour necrosis factor/lymphotoxin alpha/lymphotoxin beta locus and primary Sjogrens syndrome in Scandinavian samples

Objectives Lymphotoxin beta (LTB) has been found to be upregulated in salivary glands of patients with primary Sjogrens syndrome (pSS). An animal model of pSS also showed ablation of the lymphoid organisation and a marked improvement in salivary gland function on blocking the LTB receptor pathway. This study aimed to investigate whether single-nucleotide polymorphisms (SNP) in the lymphotoxin alpha (LTA)/LTB/tumour necrosis factor (TNF) gene clusters are associated with pSS. less thanbrgreater than less thanbrgreater thanMethods 527 pSS patients and 532 controls participated in the study, all of Caucasian origin from Sweden and Norway. 14 SNP markers were genotyped and after quality control filtering, 12 SNP were analysed for their association with pSS using single marker and haplotype tests, and corrected by permutation testing. less thanbrgreater than less thanbrgreater thanResults Nine markers showed significant association with pSS at the p=0.05 level. Markers rs1800629 and rs909253 showed the strongest genotype association (p=1.64E-11 and p=4.42E-08, respectively, after correcting for sex and country of origin). When the analysis was conditioned for the effect of rs1800629, only the association with rs909253 remained nominally significant (p=0.027). In haplotype analyses the strongest effect was observed for the haplotype rs909253G_rs1800629A (p=9.14E-17). The associations were mainly due to anti-Ro/SSA and anti-La/SSB antibody-positive pSS. less thanbrgreater than less thanbrgreater thanConclusions A strong association was found between several SNP in the LTA/LTB/TNF alpha locus and pSS, some of which led to amino acid changes. These data suggest a role for this locus in the development of pSS. Further studies are needed to examine if the genetic effect described here is independent of the known genetic association between HLA and pSS.Funding Agencies|Western Norway Regional Health Authority||Research Council of Norway||Strategic Research Program at Helse Bergen||Broegelmann Foundation||University of Bergen||Bergens forskningsstiftelse||Swedish Research Council||Stockholm County Council||Goran Gustafsson Foundation||Torsten and Ragnar Soderberg Foundation||King Gustaf the Vth 80-year Foundation||Anna-Greta Crafoord Foundation||Malmo University Hospital Cancer Research Foundation||Vinnova||Vardalstiftelsen||Swedish Foundation for Strategic Research||Swedish Rheumatism Association||Invest in Sweden Agency||KK-stiftelsen|