| 1. |
- Imgenberg-Kreuz, Juliana, et al.
(författare)
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DNA Methylation-Based Interferon Scores Associate With Sub-Phenotypes in Primary Sjögren's Syndrome
- 2021
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Ingår i: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- 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 > mean(controls) +2SD(controls) (IFN score > 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 < 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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| 2. |
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| 3. |
- Imgenberg-Kreuz, Juliana, et al.
(författare)
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Genome-wide DNA methylation analysis in multiple tissues in primary Sjögren's syndrome reveals regulatory effects at interferon-induced genes
- 2016
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 75:11, s. 2029-2036
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Increasing evidence suggests an epigenetic contribution to the pathogenesis of autoimmune diseases, including primary Sjögren's Syndrome (pSS). The aim of this study was to investigate the role of DNA methylation in pSS by analysing multiple tissues from patients and controls.METHODS: Genome-wide DNA methylation profiles were generated using HumanMethylation450K BeadChips for whole blood, CD19+ B cells and minor salivary gland biopsies. Gene expression was analysed in CD19+ B cells by RNA-sequencing. Analysis of genetic regulatory effects on DNA methylation at known pSS risk loci was performed.RESULTS: We identified prominent hypomethylation of interferon (IFN)-regulated genes in whole blood and CD19+ B cells, including at the genes MX1, IFI44L and PARP9, replicating previous reports in pSS, as well as identifying a large number of novel associations. Enrichment for genomic overlap with histone marks for enhancer and promoter regions was observed. We showed for the first time that hypomethylation of IFN-regulated genes in pSS B cells was associated with their increased expression. In minor salivary gland biopsies we observed hypomethylation of the IFN-induced gene OAS2. Pathway and disease analysis resulted in enrichment of antigen presentation, IFN signalling and lymphoproliferative disorders. Evidence for genetic control of methylation levels at known pSS risk loci was observed.CONCLUSIONS: Our study highlights the role of epigenetic regulation of IFN-induced genes in pSS where replication is needed for novel findings. The association with altered gene expression suggests a functional mechanism for differentially methylated CpG sites in pSS aetiology.
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| 4. |
- Norheim, Katrine Brække, et al.
(författare)
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A possible genetic association with chronic fatigue in primary Sjögren's syndrome : a candidate gene study
- 2014
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Ingår i: Rheumatology International. - : Springer Science and Business Media LLC. - 0172-8172 .- 1437-160X. ; 34:2, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- Fatigue is prevalent and disabling in primary Sjögren's syndrome (pSS). Results from studies in chronic fatigue syndrome (CFS) indicate that genetic variation may influence fatigue. The aim of this study was to investigate single nucleotide polymorphism (SNP) variations in pSS patients with high and low fatigue. A panel of 85 SNPs in 12 genes was selected based on previous studies in CFS. A total of 207 pSS patients and 376 healthy controls were genotyped. One-hundred and ninety-three patients and 70 SNPs in 11 genes were available for analysis after quality control. Patients were dichotomized based on fatigue visual analogue scale (VAS) scores, with VAS <50 denominated "low fatigue" (n = 53) and VAS ≥50 denominated "high fatigue" (n = 140). We detected signals of association with pSS for one SNP in SLC25A40 (unadjusted p = 0.007) and two SNPs in PKN1 (both p = 0.03) in our pSS case versus control analysis. The association with SLC25A40 was stronger when only pSS high fatigue patients were analysed versus controls (p = 0.002). One SNP in PKN1 displayed an association in the case-only analysis of pSS high fatigue versus pSS low fatigue (p = 0.005). This candidate gene study in pSS did reveal a trend for associations between genetic variation in candidate genes and fatigue. The results will need to be replicated. More research on genetic associations with fatigue is warranted, and future trials should include larger cohorts and multicentre collaborations with sharing of genetic material to increase the statistical power.
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| 5. |
- Norheim, Katrine Braekke, et al.
(författare)
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Epigenome-wide DNA methylation patterns associated with fatigue in primary Sjogren's syndrome
- 2016
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Ingår i: Rheumatology. - : Oxford University Press (OUP). - 1462-0324 .- 1462-0332. ; 55:6, s. 1074-1082
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Chronic fatigue is a common, disabling and poorly understood phenomenon. Recent studies indicate that epigenetic mechanisms may be involved in the expression of fatigue, a prominent feature of primary SS (pSS). The aim of this study was to investigate whether DNA methylation profiles of whole blood are associated with fatigue in patients with pSS. Methods. Forty-eight pSS patients with high (n = 24) or low (n = 24) fatigue as measured by a visual analogue scale were included. Genome-wide DNA methylation was investigated using the Illumina HumanMethylation450 BeadChip array. After quality control, a total of 383 358 Cytosine-phosphate-Guanine (CpG) sites remained for further analysis. Age, sex and differential cell count estimates were included as covariates in the association model. A false discovery rate-corrected P < 0.05 was considered significant, and a cut-off of 3% average difference in methylation levels between high- and low-fatigue patients was applied. Results. A total of 251 differentially methylated CpG sites were associated with fatigue. The CpG site with the most pronounced hypomethylation in pSS high fatigue annotated to the SBF2-antisense RNA1 gene. The most distinct hypermethylation was observed at a CpG site annotated to the lymphotoxin alpha gene. Functional pathway analysis of genes with differently methylated CpG sites in subjects with high vs low fatigue revealed enrichment in several pathways associated with innate and adaptive immunity. Conclusion. Some genes involved in regulation of the immune system and in inflammation are differently methylated in pSS patients with high vs low fatigue. These findings point to functional networks that may underlie fatigue. Epigenetic changes could constitute a fatigue-regulating mechanism in pSS.
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| 6. |
- Norheim, Katrine Braekke, et al.
(författare)
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Genetic variants at the RTP4/MASP1 locus are associated with fatigue in Scandinavian patients with primary Sjogren's syndrome
- 2021
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Ingår i: RMD Open. - : BMJ Publishing Group Ltd. - 2056-5933. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Fatigue is common and severe in primary Sjogren's syndrome (pSS). The aim of this study was to identify genetic determinants of fatigue in pSS through a genome-wide association study. Methods Patients with pSS from Norway, Sweden, UK and USA with fatigue and genotype data available were included. After genotype imputation and quality control, 682 patients and 4 966 157 genetic markers were available. Association analysis in each cohort using linear regression with fatigue as a continuous variable and meta-analyses between the cohorts were performed. Results Meta-analysis of the Norwegian and Swedish cohorts identified five polymorphisms within the same linkage disequilibrium block at the receptor transporter protein 4 (RTP4)/MASP1 locus associated with fatigue with genome-wide significance (GWS) (p<5x10(-8)). Patients homozygous for the major allele scored 25 mm higher on the fatigue Visual Analogue Scale than patients homozygous for the minor allele. There were no variants associated with fatigue with GWS in meta-analyses of the US/UK cohorts, or all four cohorts. RTP4 expression in pSS B cells was upregulated and positively correlated with the type I interferon score. Expression quantitative trait loci effects in whole blood for fatigue-associated variants at RTP4/MASP1 and levels of RTP4 and MASP1 expression were identified. Conclusion Genetic variations at RTP4/MASP1 are associated with fatigue in Scandinavian pSS patients. RTP4 encodes a Golgi chaperone that influences opioid pain receptor function and MASP1 is involved in complement activation. These results add evidence for genetic influence over fatigue in pSS.
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| 7. |
- Ramirez, Jorge, et al.
(författare)
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Difference in Clinical Presentation between Female and Male Patients with Primary Sjogren's Syndrome at Diagnosis and in Long-Term Follow-up
- 2017
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Ingår i: Arthritis & Rheumatology. - : Wiley-Blackwell. - 2326-5191 .- 2326-5205. ; 69
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background/Purpose: Despite men being less prone to develop autoimmune diseases, male sex has been associated with a more severe disease course in several systemic autoimmune diseases. In the present study, we aimed to identify differences in clinical presentation between the sexes at the time of diagnosis and during long-term follow-up of primary Sjögren's syndrome (pSS), and to establish whether male sex is associated with a more severe form of pSS. Methods: Incident, treatment naïve patients (n=199, 186 females and 13 males) from Stockholm, Sweden were prospectively included during a 5-year period and examined for items of classification criteria for pSS as well as extraglandular manifestations (EGM). Serum was sampled at the time of diagnosis and anti-Ro52/SSA levels measured by ELISA. Replication of significant findings was confirmed in an independent cohort of incident pSS patients from Pisa, Italy (n=377, 368 females and 9 males), and meta-analysis performed. We further studied a cohort of 967 patients with prevalent pSS (899 females and 68 males) from Scandinavian clinical centers. The mean follow-up time (years) was 8.8 ± 7.6 for women and 8.5 ± 6.2 for men (ns). Clinical data including serological and hematological parameters, glandular, EGM and comorbidities were compared between men and women. Results: An increased frequency of EGM in men at diagnosis was observed and replicated (p=0.05, p=0.0003, and pmeta=0.002, respectively). This related to pulmonary involvement, vasculitis and lymphadenopathy being more common in men, for whom a lower age at diagnosis was observed in the exploratory cohort. Additionally, SSA positive male patients had significantly higher levels of anti-Ro52 levels than their female counterparts (p=0.02). After long-term follow-up, male patient serology was characterized by more frequent positivity for anti-SSA and anti-SSB (p=0.02), and ANA (p=0.02). Also, men with pSS were more frequently diagnosed with interstitial lung disease (p=0.008), lymphadenopathy (p=0.04) and lymphoma (p=0.007). Conversely, concomitant hypothyroidism was more common among female patients (p=0.009). Conclusion: Our analysis of two independent cohorts of incident pSS and a large cohort of prevalent pSS demonstrates significant differences between women and men with pSS. Notably, men present with more EGM, enhanced serological profile and a higher frequency of lymphoma development.
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| 8. |
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| 9. |
- Sepulveda, Jorge I. Ramirez, et al.
(författare)
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Long-term follow-up in primary Sjögren's syndrome reveals differences in clinical presentation between female and male patients
- 2017
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Ingår i: Biology of Sex Differences. - : BioMed Central. - 2042-6410. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite men being less prone to develop autoimmune diseases, male sex has been associated with a more severe disease course in several systemic autoimmune diseases. In the present study, we aimed to investigate differences in the clinical presentation of primary Sjogren's syndrome (pSS) between the sexes and establish whether male sex is associated with a more severe form of long-term pSS. Methods: Our study population included 967 patients with pSS (899 females and 68 males) from Scandinavian clinical centers. The mean follow-up time (years) was 8.8 +/- 7.6 for women and 8.5 +/- 6.2 for men (ns). Clinical data including serological and hematological parameters and glandular and extraglandular manifestations were compared between men and women. Results: Male patient serology was characterized by more frequent positivity for anti-Ro/SSA and anti-La/SSB (p = 0. 02), and ANA (p = 0.02). Further, men with pSS were more frequently diagnosed with interstitial lung disease (p = 0. 008), lymphadenopathy (p = 0.04) and lymphoma (p = 0.007). Conversely, concomitant hypothyroidism was more common among female patients (p = 0.009). Conclusions: We observe enhanced serological responses and higher frequencies of lymphoma-related extraglandular manifestations in men with pSS. Notably, lymphoma itself was also significantly more common in men. These observations may reflect an aggravated immune activation and a more severe pathophysiological state in male patients with pSS and indicate a personalized managing of the disease due to the influence of the sex of patients with pSS.
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| 10. |
- Surowiec, Izabella, et al.
(författare)
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Metabolomics study of fatigue in patients with rheumatoid arthritis na < ve to biological treatment
- 2016
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Ingår i: Rheumatology International. - : Springer Science and Business Media LLC. - 0172-8172 .- 1437-160X. ; 36:5, s. 703-711
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Tidskriftsartikel (refereegranskat)abstract
- Fatigue occurs in all chronic inflammatory diseases, in cancer, and in some neurological conditions. Patients often regard fatigue as one of their most debilitating problems, but currently there is no established treatment and the mechanisms that lead to and regulate fatigue are incompletely understood. Our objective was to more completely understand the physiology of this phenomenon. Twenty-four patients with rheumatoid arthritis (RA) na < ve to treatment with biological drugs were enrolled for the study. Fatigue was measured with a fatigue visual analogue scale (fVAS). Ethylenediaminetetraacetic acid (EDTA) plasma samples were subjected to gas chromatography-time-of-flight mass spectrometry (GC/MS-TOF)-based metabolite profiling. Obtained metabolite data were evaluated by multivariate data analysis with orthogonal projections to latent structures (OPLS) method to pinpoint metabolic changes related to fatigue severity. A significant multivariate OPLS model was obtained between the fVAS scores and the measured metabolic levels. Increasing fatigue scores were associated with a metabolic pattern characterized by down-regulation of metabolites from the urea cycle, fatty acids, tocopherols, aromatic amino acids, and hypoxanthine. Uric acid levels were increased. Apart from fatigue, we found no other disease-related variables that might be responsible for these changes. Our MS-based metabolomic approach demonstrated strong associations between fatigue and several biochemical patterns related to oxidative stress.
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