| 1. |
- Appel, Silke, et al.
(author)
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Potential association of muscarinic receptor 3 gene variants with primary Sjogren's syndrome
- 2011
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In: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 70:7, s. 1327-1329
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Journal article (peer-reviewed)abstract
- Background: Primary Sjögren's syndrome (pSS) is characterised by a chronic inflammation of exocrine glands. Salivary gland infiltrates, however, do not correlate well with disease symptoms, and a primary role for the salivary gland parenchyma in disease development has been suggested. Specifically, dysfunction of exocrine pathways involving the muscarinic receptor 3 (CHRM3) has been indicated. Objective: To investigate possible genetic divergence in the CHRM3 gene in patients with pSS. Methods: 530 patients with pSS and 532 controls from a combined Swedish and Norwegian cohort were genotyped for 84 single nucleotide polymorphisms (SNPs) distributed throughout CHRM3. Results: Genetic association was observed with five SNPs localised in intron 3 and 4 of CHRM3, the strongest being rs7548522 (minor allele frequency = 0.06, OR=1.93, 95% CI (1.24 to 3.01); p=0.0033). In addition, clinical parameters, including focus score, abnormal Schirmer's test and presence of autoantibodies, were associated with different SNPs in CHRM3. Conclusion: The study demonstrates a novel association of CHRM3 polymorphisms with pSS, suggesting a functional role for CHRM3 and the salivary gland parenchyma in the pathogenesis of pSS.
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| 2. |
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| 3. |
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| 4. |
- Björk, Albin, et al.
(author)
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Protein and DNA methylation-based scores as surrogate markers for interferon system activation in patients with primary Sjögren's syndrome
- 2020
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In: RMD Open. - : BMJ PUBLISHING GROUP. - 2056-5933. ; 6:1
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Journal article (peer-reviewed)abstract
- Objective: Standard assessment of interferon (IFN) system activity in systemic rheumatic diseases depends on the availability of RNA samples. In this study, we describe and evaluate alternative methods using plasma, serum and DNA samples, exemplified in the IFN-driven disease primary Sjogren's syndrome (pSS).Methods: Patients with pSS seropositive or negative for anti-SSA/SSB and controls were included. Protein-based IFN (pIFN) scores were calculated from levels of PD-1, CXCL9 and CXCL10. DNA methylation-based (DNAm) IFN scores were calculated from DNAm levels at RSAD2, IFIT1 and IFI44L. Scores were compared with mRNA-based IFN scores measured by quantitative PCR (qPCR), Nanostring or RNA sequencing (RNAseq).Results: mRNA-based IFN scores displayed strong correlations between B cells and monocytes (r=0.93 and 0.95, p<0.0001) and between qPCR and Nanostring measurements (r=0.92 and 0.92, p<0.0001). The pIFN score in plasma and serum was higher in patients compared with controls (p<0.0001) and correlated well with mRNA-based IFN scores (r=0.62-0.79, p<0.0001), as well as with each other (r=0.94, p<0.0001). Concordance of classification as 'high' or 'low' IFN signature between the pIFN score and mRNA-based IFN scores ranged from 79.5% to 88.6%, and the pIFN score was effective at classifying patients and controls (area under the curve, AUC=0.89-0.93, p<0.0001). The DNAm IFN score showed strong correlation to the RNAseq IFN score (r=0.84, p<0.0001) and performed well in classifying patients and controls (AUC=0.96, p<0.0001).Conclusions: We describe novel methods of assessing IFN system activity in plasma, serum or DNA samples, which may prove particularly valuable in studies where RNA samples are not available.
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| 5. |
- Bolstad, Anne Isine, et al.
(author)
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Association between genetic variants in the tumour necrosis factor/lymphotoxin α/lymphotoxin β locus and primary Sjogren's syndrome in Scandinavian samples
- 2012
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In: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 71:6, s. 981-988
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Journal article (peer-reviewed)abstract
- OBJECTIVES: Lymphotoxin β (LTB) has been found to be upregulated in salivary glands of patients with primary Sjögren's 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 α (LTA)/LTB/tumour necrosis factor (TNF) gene clusters are associated with pSS.METHODS: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.RESULTS: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.CONCLUSIONS:A strong association was found between several SNP in the LTA/LTB/TNFα 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.
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| 6. |
- Idborg, Helena, et al.
(author)
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Two subgroups in systemic lupus erythematosus with features of antiphospholipid or Sjogren's syndrome differ in molecular signatures and treatment perspectives
- 2019
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In: Arthritis Research & Therapy. - : BioMed Central. - 1478-6362 .- 1478-6354. ; 21
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Journal article (peer-reviewed)abstract
- BackgroundPrevious studies and own clinical observations of patients with systemic lupus erythematosus (SLE) suggest that SLE harbors distinct immunophenotypes. This heterogeneity might result in differences in response to treatment in different subgroups and obstruct clinical trials. Our aim was to understand how SLE subgroups may differ regarding underlying pathophysiology and characteristic biomarkers.MethodsIn a cross-sectional study, including 378 well-characterized SLE patients and 316 individually matched population controls, we defined subgroups based on the patients' autoantibody profile at inclusion. We selected a core of an antiphospholipid syndrome-like SLE (aPL+ group; positive in the lupus anticoagulant (LA) test and negative for all three of SSA (Ro52 and Ro60) and SSB antibodies) and a Sjogren's syndrome-like SLE (SSA/SSB+ group; positive for all three of SSA (Ro52 and Ro60) and SSB antibodies but negative in the LA test). We applied affinity-based proteomics, targeting 281 proteins, together with well-established clinical biomarkers and complementary immunoassays to explore the difference between the two predefined SLE subgroups.ResultsThe aPL+ group comprised 66 and the SSA/SSB+ group 63 patients. The protein with the highest prediction power (receiver operating characteristic (ROC) area under the curve=0.89) for separating the aPL+ and SSA/SSB+ SLE subgroups was integrin beta-1 (ITGB1), with higher levels present in the SSA/SSB+ subgroup. Proteins with the lowest p values comparing the two SLE subgroups were ITGB1, SLC13A3, and CERS5. These three proteins, rheumatoid factor, and immunoglobulin G (IgG) were all increased in the SSA/SSB+ subgroup. This subgroup was also characterized by a possible activation of the interferon system as measured by high KRT7, TYK2, and ETV7 in plasma. In the aPL+ subgroup, complement activation was more pronounced together with several biomarkers associated with systemic inflammation (fibrinogen, -1 antitrypsin, neutrophils, and triglycerides).ConclusionsOur observations indicate underlying pathogenic differences between the SSA/SSB+ and the aPL+ SLE subgroups, suggesting that the SSA/SSB+ subgroup may benefit from IFN-blocking therapies while the aPL+ subgroup is more likely to have an effect from drugs targeting the complement system. Stratifying SLE patients based on an autoantibody profile could be a way forward to understand underlying pathophysiology and to improve selection of patients for clinical trials of targeted treatments.
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| 7. |
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| 8. |
- Järvinen, Tiina M., et al.
(author)
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Polymorphisms of the ITGAM Gene Confer Higher Risk of Discoid Cutaneous Than of Systemic Lupus Erythematosus
- 2010
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:11, s. e14212-
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Journal article (peer-reviewed)abstract
- Background: Lupus erythematosus (LE) is a heterogeneous disease ranging from mainly skin-restricted manifestations (discoid LE [DLE] and subacute cutaneous LE) to a progressive multisystem disease (systemic LE [SLE]). Genetic association studies have recently identified several strong susceptibility genes for SLE, including integrin alpha M (ITGAM), also known as CD11b, whereas the genetic background of DLE is less clear. Principal Findings: To specifically investigate whether ITGAM is a susceptibility gene not only for SLE, but also for cutaneous DLE, we genotyped 177 patients with DLE, 85 patients with sporadic SLE, 190 index cases from SLE families and 395 population control individuals from Finland for nine genetic markers at the ITGAM locus. SLE patients were further subdivided by the presence or absence of discoid rash and renal involvement. In addition, 235 Finnish and Swedish patients positive for Ro/SSA-autoantibodies were included in a subphenotype analysis. Analysis of the ITGAM coding variant rs1143679 showed highly significant association to DLE in patients without signs of systemic disease (P-value = 4.73x10(-11), OR = 3.20, 95% CI = 2.23-4.57). Significant association was also detected to SLE patients (P-value = 8.29x10(-6), OR = 2.14, 95% CI = 1.52-3.00), and even stronger association was found when stratifying SLE patients by presence of discoid rash (P-value = 3.59x10(-8), OR = 3.76, 95% CI = 2.29-6.18). Significance: We propose ITGAM as a novel susceptibility gene for cutaneous DLE. The risk effect is independent of systemic involvement and has an even stronger genetic influence on the risk of DLE than of SLE.
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| 9. |
- Kottyan, Leah C., et al.
(author)
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The IRF5-TNPO3 association with systemic lupus erythematosus has two components that other autoimmune disorders variably share.
- 2015
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 24:2, s. 582-596
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Journal article (peer-reviewed)abstract
- Exploiting genotyping, DNA sequencing, imputation and trans-ancestral mapping, we used Bayesian and frequentist approaches to model the IRF5-TNPO3 locus association, now implicated in two immunotherapies and seven autoimmune diseases. Specifically, in systemic lupus erythematosus (SLE), we resolved separate associations in the IRF5 promoter (all ancestries) and with an extended European haplotype. We captured 3230 IRF5-TNPO3 high-quality, common variants across 5 ethnicities in 8395 SLE cases and 7367 controls. The genetic effect from the IRF5 promoter can be explained by any one of four variants in 5.7 kb (P-valuemeta = 6 × 10(-49); OR = 1.38-1.97). The second genetic effect spanned an 85.5-kb, 24-variant haplotype that included the genes IRF5 and TNPO3 (P-valuesEU = 10(-27)-10(-32), OR = 1.7-1.81). Many variants at the IRF5 locus with previously assigned biological function are not members of either final credible set of potential causal variants identified herein. In addition to the known biologically functional variants, we demonstrated that the risk allele of rs4728142, a variant in the promoter among the lowest frequentist probability and highest Bayesian posterior probability, was correlated with IRF5 expression and differentially binds the transcription factor ZBTB3. Our analytical strategy provides a novel framework for future studies aimed at dissecting etiological genetic effects. Finally, both SLE elements of the statistical model appear to operate in Sjögrens syndrome and systemic sclerosis whereas only the IRF5-TNPO3 gene-spanning haplotype is associated with primary biliary cirrhosis, demonstrating the nuance of similarity and difference in autoimmune disease risk mechanisms at IRF5-TNPO3.
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| 10. |
- Kvarnström, Marika
(author)
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Pathophysiological mechanisms and clinical manifestations in primary Sjögren’s syndrome and Systemic lupus erythematosus (SLE)
- 2014
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Doctoral thesis (other academic/artistic)abstract
- Primary Sjögren’s syndrome (pSS) is a systemic inflammatory autoimmune condition. The etiology of pSS is mainly unknown, but it has been suggested that environmental factors trigger an immune response in genetically susceptible individuals. The disease is characterized by chronic inflammation which results in progressive destruction of exocrine glands, primarily the salivary and lacrimal glands, leading to symptoms of dryness, mainly in the mouth and eyes. Patients may also experience symptoms of exocrine dysfunction and dryness in other parts of the body. Autoantibodies against the antigens Ro/SSA (Ro52 and Ro60) and La/SSB, are a well-known sign of dysregulation of the immune system. Extraglandular manifestations (EGM) are present in a subset of patients with pSS. In a population based prospective study we included all patients referred to the Department of Rheumatology for suspected pSS during a five-year period. The patients were evaluated using a structured procedure according to the 2002 Revised American-European Consensus Criteria for Sjögren’s syndrome. Of referred individuals, 199 of 781 patients were diagnosed with pSS. We found an annual incidence rate of pSS in the Karolinska University Hospital catchment area of 3.1 (95% CI 2.3-4.3) cases per 100,000 adult inhabitants. In this cohort, we noted lower figures for severe EGM such as lung and neurological involvement than previously reported for prevalent pSS. Also, the frequency of autoantibodies including ANA, anti-Ro/SSA and anti-La/SSB was lower compared to other cohorts. Subsets of these patients were recruited and included in genetic studies. We contributed with 79 pSS patients in a candidate-gene association case control study in 540 patients with pSS and 532 controls, from Sweden and Norway. Three novel gene loci, not previously associated with pSS, were identified: the early B-cell factor 1 (EBF1) gene, the family with sequence similarity 167 member A–B-lymphoid tyrosine kinase (FAM167A–BLK) locus, and the tumor necrosis factor superfamily (TNFSF4=Ox40L) gene. Variations in the gene loci for interferon regulation factor 5 (IRF5) and signal transducer and activator of transcription 4 (STAT4) were confirmed. The three novel gene variants are involved in B-cell development and activation. In an international multicenter case control genome-wide association study (GWAS)/ large-scale association study of pSS, we contributed with 99 patients. The results confirmed associations with variations in the gene loci of the human leukocyte antigen (HLA) region, IRF5, STAT4, FAM167A-BLK, chemokine C-X-C motif receptor 5 (DX6-CXCR), and TNFAIP3 interacting protein 1 (TNIP1) at a genome-wide significance level. In addition, 29 further suggested associations (p meta < 5 × 10−5) were observed. The major part of these genes is involved in both innate and adaptive immune responses. We observed that the autoantigen Ro52 was expressed and upregulated in salivary glands of patients with primary Sjögren’s syndrome. This was noted in biopsies from 28 pSS patients and 19 non-pSS controls from Sweden and Norway. The degree of expression was correlated with the level of inflammation in the tissue. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multiple organ manifestations and immunological dysregulation including production of a large set of autoantibodies targeting different epitopes. We showed that antibodies to the RING domain of Ro52, which is the functionally active domain with E3 ligase activity, were significantly correlated with disease activity as measured by the SLAM score in a well-characterized cohort of SLE patients. In conclusion, the results of these studies have highlighted the role of the immune system in the pathogenesis in pSS and SLE.
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| 11. |
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| 12. |
- Mofors, Johannes, et al.
(author)
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Cigarette smoking patterns preceding primary Sjögren's syndrome
- 2020
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In: RMD Open. - : BMJ Publishing Group Ltd. - 2056-5933. ; 6:3
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Journal article (peer-reviewed)abstract
- Background: Cigarette smoking is a well-established risk factor for several autoimmune diseases, but its role in primary Sjogren's syndrome (pSS) remains unclear. Here, we investigated the association between cigarette smoking and subsequent development of pSS.Methods: Information on smoking habits was collected from lifestyle habit questionnaires of patients with pSS (n=815) and a matched control group (n=4425) for a case-control study. Differences in smoking exposure were analysed by conditional logistic regression. Potential interactions between smoking and risk-associated human leucocyte antigens (HLA) were assessed by multivariate regression.Results: The fraction of patients with pSS having ever smoked prior to diagnosis was lower than in controls (OR 0.67, 95% CI 0.55 to 0.81). Current smoking at diagnosis was also less prevalent in cases (OR 0.37, 95% CI 0.26 to 0.53). However, period prevalence of smoking during early adulthood was not statistically different from controls (OR 0.89, 95% CI 0.66 to 1.22) but markedly decreased over time. This was partly due to patients being more prone to stop smoking, starting already 30 years prior to diagnosis (OR 2.01, 95% CI 1.22 to 3.30). Smoking patterns were also stratified by autoantibody status, yielding similar estimates. No interaction effects between HLA-DRB1 haplotypes and smoking were observed.Conclusion: The observed smoking patterns indicate that individuals who develop pSS smoke equally much as the general population during early life but are then more prone to stop. The data can be interpreted as smoking conferring protective effects, or reflecting early symptoms of pSS that affect smoking habits, emphasising the slow, progressive development of the disease.
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| 13. |
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| 14. |
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| 15. |
- Nordmark, Gunnel, et al.
(author)
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Association of Genes in the NF-κB Pathway with Antibody-Positive Primary Sjögren's Syndrome
- 2013
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In: Scandinavian Journal of Immunology. - : Wiley-Blackwell. - 0300-9475 .- 1365-3083. ; 78:5, s. 447-454
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Journal article (peer-reviewed)abstract
- Primary Sjogrens 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-B in primary SS. NF-B 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-B and of IKBKE (IKK epsilon), which is an NF-B 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=3.4x10(-5), OR=1.33, 95%CI: 1.16-1.52 for rs3792783 and P=1.3x10(-3), OR=1.21, 95%CI: 1.08-1.36 for rs7708392). A TNIP1 risk haplotype was associated with antibody-positive primary SS (P=5.7x10(-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.
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| 16. |
- Ruacho, Guillermo, et al.
(author)
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Sjögren Syndrome in Systemic Lupus Erythematosus : A Subset Characterized by a Systemic Inflammatory State
- 2020
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In: Journal of Rheumatology. - : The Journal of Rheumatology. - 0315-162X .- 1499-2752. ; 47:6, s. 865-875
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Journal article (peer-reviewed)abstract
- Objective. An often-neglected subset of patients with systemic lupus erythematosus (SLE) is those with secondary Sjogren syndrome (SLE-sSS). Further, primary SS overlaps and can be difficult to delineate from SLE. To shed light on the SLE-sSS subset, we investigated a large and well-characterized SLE cohort, comparing patients with SLE-sSS and SLE patients without SS (SLE-nonsSS) and controls. Methods. We included 504 consecutive patients with SLE, fulfilling the 1982 revised American College of Rheumatology criteria, and 319 controls from the general population, matched for age and sex to the first 319 patients. SLE-sSS was defined according to the American-European Consensus Criteria (AECC). A thorough clinical examination, including subjective and objective quantifications of sicca symptoms, was performed in all participants. Autoantibodies and 20 selected cytokines were measured by luminex and multiplex analysis, respectively. Results. SLE-sSS, as defined by AECC, occurred in 23% of the patients with SLE. In comparison to SLE-nonsSS, the SLE-sSS group was older and more frequently female. Leukopenia and peripheral neuropathy were more frequent and nephritis less frequent. Circulating levels of 6/20 investigated proinflammatory cytokines [tumor necrosis factor-alpha, interleukin (IL) 6, monocyte chemoattractant protein 4, macrophage inflammatory protein 1 beta, IL-12/IL-23p40, and interferon gamma-induced protein 10], total IgG, anti-SSA/Ro52, anti-SSA/Ro60, anti-SSB/La antibodies, and rheumatoid factor (IgM and IgA) were higher in the SLE-sSS group (p < 0.05 for all comparisons). Conclusion. The frequency of SLE-sSS increased with age and affected roughly one-quarter of all patients with SLE. Despite less internal organ involvement, a systemic inflammatory state with high levels of proinflammatory cytokines is present in the SLE-sSS subgroup. This is a novel observation that may affect future understanding and treatment of the SLE-sSS subset.
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| 17. |
- Thorlacius, Guðný Ella, et al.
(author)
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Genetic and clinical basis for two distinct subtypes of primary Sjögren's syndrome
- 2021
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In: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 60:2, s. 837-848
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Journal article (peer-reviewed)abstract
- ObjectivesClinical 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.MethodsWe 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.ResultsWe 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.ConclusionTwo 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.
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| 18. |
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