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| 2. |
- Ahmad Kiadaliri, Aliasghar, et al.
(författare)
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Rheumatoid arthritis as underlying cause of death in 31 countries, 1987-2011: Trend analysis of WHO mortality database
- 2017
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5205 .- 2326-5191. ; 69:8, s. 1560-1565
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Tidskriftsartikel (refereegranskat)abstract
- Objective To examine trends in rheumatoid arthritis (RA) as an underlying cause of death (UCD) in 31 countries across the globe during 1987-2011. Methods Data on mortality and population were collected from the World Health Organization mortality database and the United Nations. Age-standardized mortality rates (ASMR) were calculated by means of direct standardization. We applied joinpoint regression analysis for trend analysis. Between-country disparities were examined using between-country variance, and Gini coefficient. Due to low numbers of deaths, we smoothed our ASMR using a three-year moving average. The changes in number of RA deaths between 1987 and 2011 were decomposed using two counterfactual scenarios. Results The absolute number of deaths with RA registered as UCD declined from 9281 (0.12% of all-cause deaths) in 1987 to 8428 in 2011 (0.09% of all-cause deaths). The mean ASMR declined from 7.1/million person-years in 1987-89 to 3.7 in 2009-11 (48.2% reduction). Reduction of 25% or more in ASMR occurred in 21 countries while a corresponding increase was observed in 3 countries. There was a persistent reduction in RA mortality and, on average, the ASMR declined by 3.0% per year. The absolute and relative between-country disparities declined over the study period.CONCLUSION: Mortality rates attributable to RA have declined globally. However, there were substantial between-country disparities in RA mortality, though the disparities decreased over time. Population aging combined with fall in RA mortality may lead to an increase in the economic burden of disease that should be taken into consideration in policy-making. This article is protected by copyright. All rights reserved.
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| 4. |
- Ali, Abukar, 1988, et al.
(författare)
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Antibiotic-killed Staphylococcus aureus induces destructive arthritis in mice.
- 2015
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Ingår i: Arthritis & rheumatology (Hoboken, N.J.). - : Wiley. - 2326-5205 .- 2326-5191. ; 67:1, s. 107-116
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Permanent reduction in joint function is a severe post-infectious complication in patients with Staphylococcus aureus septic arthritis. This reduction in joint function might be caused by persistent joint inflammation after the adequate eradication of bacteria by antibiotics. Methods: We studied whether antibiotic-killed S. aureus induced joint inflammation in mice and elucidated the molecular and cellular mechanism of this type of arthritis. Results: The intraarticular injection of antibiotic-killed S. aureus induced mild to moderate synovitis and bone erosions that lasted for a minimum of 14 days. The frequency and severity of synovitis were significantly reduced in tumor necrosis factor receptor 1 (TNFR1), receptor for Advanced Glycation End Products (RAGE), and toll like receptor 2 (TLR2) knockout mice compared with wild-type animals. The combined depletion of monocytes and neutrophils resulted in a significantly lower frequency of synovitis. Among bacterial factors, insoluble cell debris played a more important role than bacterial DNA or soluble components in inducing joint inflammation. Importantly, anti-TNF therapy abrogated the joint inflammation induced by antibiotic-killed S. aureus. Conclusion: Antibiotic-killed S. aureus induced and maintained the joint inflammation that is mediated through TLR2, TNFR1, and RAGE receptor. The cross-talk between neutrophils and monocytes is responsible for this type of arthritis. Anti-TNF therapy might be used as a novel therapeutic strategy, in combination with antibiotics, to treat staphylococcal septic arthritis. © 2014 American College of Rheumatology.
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| 5. |
- Amkreutz, J. A. M. P., et al.
(författare)
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Association Between Bone Mineral Density and Autoantibodies in Patients With Rheumatoid Arthritis
- 2021
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Ingår i: Arthritis and Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 73:6, s. 921-930
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Autoantibodies, such as anti–citrullinated protein antibodies (ACPAs), have been described as inducing bone loss in rheumatoid arthritis (RA), which can also be reflected by bone mineral density (BMD). We therefore examined the association between osteoporosis and autoantibodies in two independent RA cohorts. Methods: Dual x-ray absorptiometry (DXA) of the lumbar spine and left hip was performed in 408 Dutch patients with early RA during 5 years of follow-up and in 198 Swedish patients with early RA during 10 years of follow-up. The longitudinal effect of ACPAs and other autoantibodies on several BMD measures was assessed using generalized estimating equations. Results: In the Dutch cohort, significantly lower BMD at baseline was observed in ACPA-positive patients compared to ACPA-negative patients, with an estimated marginal mean BMD in the left hip of 0.92 g/cm2 (95% confidence interval [95% CI] 0.91–0.93) versus 0.95 g/cm2 (95% CI 0.93–0.97) (P = 0.01). In line with this, significantly lower Z scores at baseline were noted in the ACPA-positive group compared to the ACPA-negative group (estimated marginal mean Z score in the left hip of 0.18 [95% CI 0.08–0.29] versus 0.48 [95% CI 0.33–0.63]) (P < 0.01). However, despite clear differences at baseline, ACPA positivity was not associated with greater decrease in absolute BMD or Z scores over time. Furthermore, there was no association between BMD and higher levels of ACPAs or other autoantibodies (rheumatoid factor and anti–carbamylated protein antibodies). In the Swedish cohort, ACPA-positive patients tended to have a higher prevalence of osteopenia at baseline (P = 0.04), but again, ACPA positivity was not associated with an increased prevalence of osteopenia or osteoporosis over time. Conclusion: The presence of ACPAs is associated with significantly lower BMD at baseline, but not with greater BMD loss over time in treated RA patients. These results suggest that ACPAs alone do not appear to contribute to bone loss after disease onset when disease activity is well-managed. © 2020 The Authors. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.
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| 7. |
- Andersson, Maria L.E., et al.
(författare)
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Autoantibodies to Disease-Related Proteins in Joints as Novel Biomarkers for the Diagnosis of Rheumatoid Arthritis
- 2023
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 75:7, s. 1110-1119
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Tidskriftsartikel (refereegranskat)abstract
- Objective. This study was undertaken to develop and characterize a multiplex immunoassay for detection of autoantibodies against peptides derived from proteins known to play a role in development of arthritis and that are also expressed in joints.Methods. We selected peptides from the human counterpart of proteins expressed in the joints, based on mouse models that showed these to be targeted by pathogenic or regulatory antibodies in vivo. Using bead-based flow immunoassays measuring IgG antibodies, we selected triple helical or cyclic peptides, containing the epitopes, to avoid collinear reactivity. We characterized the analytical performance of the immunoassay and then validated it in 3 independent rheumatoid arthritis (RA) cohorts (n = 2,110), Swedish age- and sex-matched healthy controls, and patients with osteoarthritis (OA), patients with psoriatic arthritis (PsA), and patients with systemic lupus erythematosus (SLE).Results. Screening assays showed 5 peptide antigens that discriminated RA patients from healthy controls with 99% specificity (95% confidence interval [CI] 98-100%). In our validation studies, we reproduced the discriminatory capacity of the autoantibodies in 2 other RA cohorts, showing that the autoantibodies had high discriminatory capacity for RA versus OA, PsA, and SLE. The novel biomarkers identified 22.5% (95% CI 19-26%) of early RA patients seronegative for anti-cyclic citrullinated peptide and rheumatoid factor. The usefulness of the biomarkers in identifying seronegative RA patients was confirmed in validation studies using 2 independent cohorts of RA patients and cohorts of patients with OA, PsA, and SLE.Conclusion. A multiplex immunoassay with peptides from disease-related proteins in joints was found to be useful for detection of specific autoantibodies in RA serum. Of note, this immunoassay had high discriminatory capacity for early seronegative RA.
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| 10. |
- Arnaud, Laurent, et al.
(författare)
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Effect of Corticosteroids and Cyclophosphamide on Sex Hormone Profiles in Male Patients With Systemic Lupus Erythematosus or Systemic Sclerosis
- 2017
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Ingår i: Arthritis & Rheumatology. - : WILEY. - 2326-5191 .- 2326-5205. ; 69:6, s. 1272-1279
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) are autoimmune diseases that predominantly affect female patients, and therefore fewer investigations have been conducted in men. The aim of this study was to analyze sex hormone levels in male patients with SLE and those with SSc, compared to matched controls, in relation to the use of corticosteroids and cyclophosphamide (CYC).Methods: Sex hormone levels were measured in fasting blood samples from male patients with SLE (n=71) and those with SSc (n=29) and compared to population-based, age-matched male controls. Relevant hormone profiles were identified using cluster analysis.Results: Male SLE patients had higher levels of luteinizing hormone (LH) (P<0.0001) and more frequent bioactive testosterone deficiency (P=0.02) than their matched controls. The current dosage of prednisolone correlated inversely with the levels of bioactive testosterone (r=-0.36, P=0.03). Cluster analysis identified a subset of SLE patients with increased levels of follicle-stimulating hormone, LH, and prolactin as well as lower levels of bioactive testosterone (P<0.0001) in relation to higher daily doses of prednisolone. In male SSc patients, levels of testosterone (P=0.03) and bioactive testosterone (P=0.02) were significantly lower than those in matched controls. Use of CYC during the previous year was associated with lower bioactive testosterone levels in both SLE patients (P=0.02) and SSc patients (P=0.01), after adjustment for age.Conclusion: The results of this study highlight the negative impact of corticosteroids on gonadal function in men with SLE. Furthermore, use of CYC during the year prior to study inclusion impaired bioactive testosterone levels in male patients with either SLE or SSc. Physicians should be more aware of the possibility of hypogonadism in male patients with autoimmune diseases. The need for hormonal supplementation remains to be formally evaluated in these patients.
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| 11. |
- Arvidsson, Gustav, et al.
(författare)
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Multimodal Single-Cell Sequencing of B Cells in Primary Sjögren's Syndrome
- 2024
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Ingår i: Arthritis & Rheumatology. - 2326-5191 .- 2326-5205. ; 76:2, s. 255-267
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Tidskriftsartikel (refereegranskat)abstract
- Objective. B cells are important in the pathogenesis of primary Sjögren's syndrome (pSS). Patients positive for Sjögren's syndrome antigen A/Sjögren syndrome antigen B (SSA/SSB) autoantibodies are more prone to systemic disease manifestations and adverse outcomes. We aimed to determine the role of B cell composition, gene expression, and B cell receptor usage in pSS subgroups stratified for SSA/SSB antibodies.Methods. Over 230,000 B cells were isolated from peripheral blood of patients with pSS (n = 6 SSA−, n = 8 SSA+ single positive and n = 10 SSA/SSB+ double positive) and four healthy controls and processed for single-cell RNA sequencing (scRNA-seq) and single-cell variable, diversity, and joining (VDJ) gene sequencing (scVDJ-seq).Results. We show that SSA/SSB+ patients present the highest and lowest proportion of naïve and memory B cells, respectively, and the highest up-regulation of interferon-induced genes across all B cell subtypes. Differential usage of IGHV showed that IGHV1-69 and IGHV4-30-4 were more often used in all pSS subgroups compared with controls. Memory B cells from SSA/SSB+ patients displayed a higher proportion of cells with unmutated VDJ transcripts compared with other pSS patient groups and controls, indicating altered somatic hypermutation processes. Comparison with previous studies revealed heterogeneous clonotype pools, with little overlap in CDR3 sequences. Joint analysis using scRNA-seq and scVDJ-seq data allowed unsupervised stratification of patients with pSS and identified novel parameters that correlated to disease manifestations and antibody status.Conclusion. We describe heterogeneity and molecular characteristics in B cells from patients with pSS, providing clues to intrinsic differences in B cells that affect the phenotype and outcome and allowing stratification of patients with pSS at improved resolution.
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| 12. |
- Askling, Johan, et al.
(författare)
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Is Rheumatoid Arthritis a Mortal Disease?
- 2017
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Ingår i: Arthritis & Rheumatology. - : Wiley-Blackwell. - 2326-5191 .- 2326-5205. ; 69:8, s. 1509-1511
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Tidskriftsartikel (refereegranskat)
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| 13. |
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| 14. |
- Bas, D. B., et al.
(författare)
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Collagen antibody-induced arthritis evokes persistent pain with spinal glial involvement and transient prostaglandin dependency
- 2012
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 64:12, s. 3886-3896
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivePain is one of the most debilitating symptoms reported by rheumatoid arthritis (RA) patients. While the collagen antibody–induced arthritis (CAIA) model is used for studying the effector phase of RA pathologic progression, it has not been evaluated as a model for studies of pain. Thus, this study was undertaken to examine pain-like behavior induced by anticollagen antibodies and to assess the effect of currently prescribed analgesics for RA. In addition, the involvement of spinal glia in antibody-induced pain was explored.MethodsCAIA was induced in mice by intravenous injection of a collagen antibody cocktail, followed by intraperitoneal injection of lipopolysaccharide. Disease severity was assessed by visual and histologic examination. Pain-like behavior and the antinociceptive effect of diclofenac, buprenorphine, gabapentin, pentoxifylline, and JNK-interacting protein 1 were examined in mechanical stimulation experiments. Spinal astrocyte and microglia reactivity were investigated by real-time polymerase chain reaction and immunohistochemistry.ResultsFollowing the induction of CAIA, mice developed transient joint inflammation. In contrast, pain-like behavior was observed prior to, and outlasted, the visual signs of arthritis. Whereas gabapentin and buprenorphine attenuated mechanical hypersensitivity during both the inflammatory and postinflammatory phases of arthritis, diclofenac was antinociceptive only during the inflammatory phase. Spinal astrocytes and microglia displayed time-dependent signs of activation, and inhibition of glial activity reversed CAIA-induced mechanical hypersensitivity.ConclusionCAIA represents a multifaceted model for studies exploring the mechanisms of pain induced by inflammation in the articular joint. Our findings of a time-dependent prostaglandin and spinal glial contribution to antibody-induced pain highlight the importance of using appropriate disease models to assess joint-related pain.
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| 18. |
- Bergman, Stefan, 1959-, et al.
(författare)
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Chronic Widespread Pain in Adolescents Is Highly Associated to Stress and Anxiety
- 2015
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Ingår i: Arthritis & Rheumatology. - Hoboken, NJ : John Wiley & Sons. - 2326-5191 .- 2326-5205. ; 67:Suppl. S10
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Tidskriftsartikel (refereegranskat)abstract
- Background/Purpose: Chronic widespread pain (CWP), one of the hallmarks of fibromyalgia, is not uncommon in adolescents and it has previously been shown that adolescents with pain often become young adults with pain. CWP often co-varies with anxiety, depression, and stress symptoms in adults, but the knowledge regarding this is small in youth and young adults.The aim was to study the associations between CWP, anxiety, depression and stress in adolescents attending first year of high school.Methods: A computerized questionnaire to 296 adolescents attending Swedish high school, with validated questions regarding presence and distribution of pain (Epipain mannequin), stress symptoms (ELO question), anxiety and depression (Hospital Anxiety and Depression Scale – HADS), and health related quality of life (HRQL as measured by EQ5D). Pain was considered chronic when persistent for more than three months, and the subgroup CWP was defined according to the 1990 ACR criteria for fibromyalgia. Statistical analyses in SPSS v21 with comparison of means by Student’s t-test and proportions by chi2-test or Fischer’s exact test.Results: 257 (87%) out of 296 eligible students, mean (SD) age 16.1 (0.7) and 65.8% girls, responded to the questionnaire. Prevalence of chronic pain was 20.8% and that of the subgroup CWP was 4.7%, without any gender differences (boys 18.2% vs girls 22.2%; p=0.224, and 3.4% vs 5.4%; p=0.692). High level (4 or 5 on a 5 point scale) of stress symptoms were less common in boys (16.0% vs 28.2%; p=0.015), as was possible or probable anxiety (17.1% vs 44.4%; p<0.001), but not depression (10.3% vs 12.5%; p=0.764). Students with high level of stress reported CWP five times more often than those with less stress (30.4% vs 5.8%; p=0.001). Students with probable anxiety reported CWP ten times more often than students with no anxiety (17.6% vs 1.8%; p=0.001), and CWP was also more common, but not statistically significant, in students with probable depression (20.0% vs 3.1%; p=0.163). Those reporting CWP had significantly lower HRQL (0.58 vs 0.87; p=0.038) than students with no chronic pain.Conclusion: The high prevalence of chronic pain and the strong associations between CWP and reports of stress and anxiety in adolescents highlights that a multifactorial background to chronic pain must be considered early in life. An apparent lower score in EQ5D also indicates that the presence of CWP has an marked impact on HRQL also in adolescents.
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| 19. |
- Bettiol, A., et al.
(författare)
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Mepolizumab for Eosinophilic Granulomatosis With Polyangiitis: A European Multicenter Observational Study
- 2022
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Ingår i: Arthritis and Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 74:2, s. 295-306
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveMepolizumab proved to be an efficacious treatment for eosinophilic granulomatosis with polyangiitis (EGPA) at a dose of 300 mg every 4 weeks in the randomized, controlled MIRRA trial. In a few recently reported studies, successful real-life experiences with the approved dose for treating severe eosinophilic asthma (100 mg every 4 weeks) were observed. We undertook this study to assess the effectiveness and safety of mepolizumab 100 mg every 4 weeks and 300 mg every 4 weeks in a large European EGPA cohort.MethodsWe included all patients with EGPA treated with mepolizumab at the recruiting centers in 2015–2020. Treatment response was evaluated from 3 months to 24 months after initiation of mepolizumab. Complete response to treatment was defined as no disease activity (Birmingham Vasculitis Activity Score [BVAS] = 0) and a prednisolone or prednisone dose (or equivalent) of ≤4 mg/day. Respiratory outcomes included asthma and ear, nose, and throat (ENT) exacerbations.ResultsTwo hundred three patients, of whom 191 received a stable dose of mepolizumab (158 received 100 mg every 4 weeks and 33 received 300 mg every 4 weeks) were included. Twenty-five patients (12.3%) had a complete response to treatment at 3 months. Complete response rates increased to 30.4% and 35.7% at 12 months and 24 months, respectively, and rates were comparable between mepolizumab 100 mg every 4 weeks and 300 mg every 4 weeks. Mepolizumab led to a significant reduction in BVAS score, prednisone dose, and eosinophil counts from 3 months to 24 months, with no significant differences observed between 100 mg every 4 weeks and 300 mg every 4 weeks. Eighty-two patients (40.4%) experienced asthma exacerbations (57 of 158 [36%] who received 100 mg every 4 weeks; 17 of 33 [52%] who received 300 mg every 4 weeks), and 31 patients (15.3%) experienced ENT exacerbations. Forty-four patients (21.7%) experienced adverse events (AEs), most of which were nonserious AEs (38 of 44).ConclusionMepolizumab at both 100 mg every 4 weeks and 300 mg every 4 weeks is effective for the treatment of EGPA. The 2 doses should be compared in the setting of a controlled trial.
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| 20. |
- Bianchi, Matteo, et al.
(författare)
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Contribution of rare genetic variation to disease susceptibility in a large Scandinavian myositis cohort
- 2022
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Ingår i: Arthritis & Rheumatology. - : John Wiley & Sons. - 2326-5191 .- 2326-5205. ; 74:2, s. 342-352
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Tidskriftsartikel (refereegranskat)abstract
- Objective Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of complex autoimmune conditions characterized by inflammation in skeletal muscle and extramuscular compartments, and interferon (IFN) system activation. We undertook this study to examine the contribution of genetic variation to disease susceptibility and to identify novel avenues for research in IIMs.Methods Targeted DNA sequencing was used to mine coding and potentially regulatory single nucleotide variants from ~1,900 immune-related genes in a Scandinavian case–control cohort of 454 IIM patients and 1,024 healthy controls. Gene-based aggregate testing, together with rare variant– and gene-level enrichment analyses, was implemented to explore genotype–phenotype relations.Results Gene-based aggregate tests of all variants, including rare variants, identified IFI35 as a potential genetic risk locus for IIMs, suggesting a genetic signature of type I IFN pathway activation. Functional annotation of the IFI35 locus highlighted a regulatory network linked to the skeletal muscle–specific gene PTGES3L, as a potential candidate for IIM pathogenesis. Aggregate genetic associations with AGER and PSMB8 in the major histocompatibility complex locus were detected in the antisynthetase syndrome subgroup, which also showed a less marked genetic signature of the type I IFN pathway. Enrichment analyses indicated a burden of synonymous and noncoding rare variants in IIM patients, suggesting increased disease predisposition associated with these classes of rare variants.Conclusion Our study suggests the contribution of rare genetic variation to disease susceptibility in IIM and specific patient subgroups, and pinpoints genetic associations consistent with previous findings by gene expression profiling. These features highlight genetic profiles that are potentially relevant to disease pathogenesis.
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| 23. |
- Brink, Mikael, et al.
(författare)
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Protein Profiling in Presymptomatic Individuals Separates Myeloperoxidase-Antineutrophil Cytoplasmic Antibody and Proteinase 3-Antineutrophil Cytoplasmic Antibody Vasculitides
- 2023
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 75:6, s. 996-1006
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a chronic relapsing condition with unknown etiology. To gain insight into the molecular processes underlying the disease, we examined biomarkers in blood samples collected prior to symptom onset. Methods. The National Patient Register and Cause of Death register were searched for AAV-related International Classification of Diseases, Ninth Revision and Tenth Revision codes and linked to the registers from 5 biobanks. Eighty-five AAV patients with samples predating symptom onset of AAV were identified. For each case of AAV, 2 matched controls were included. Proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA expression levels were analyzed using enzyme-linked immunosorbent assays. Using an Olink Inflammation panel, 73 of 92 proteins were included after quality control. Data were replicated in a second cohort of 48 presymptomatic individuals and 96 controls. Results. Of the 20 proteins with the lowest P values in the original cohort, 7 were replicated in the second cohort and 5 proteins were found to be significant between the groups in a meta-analysis. Eleven different pathways were identified in network enrichment analyses and were found to be significant in both cohorts. Stratification of samples obtained <= 5 years before symptom onset showed significant levels of CCL23, vascular endothelial growth factor A, and hepatocyte growth factor, which were also increased at borderline significant levels in the replication cohort (interleukin-6 was found to be significantly increased in the replication cohort). In presymptomatic AAV patients, 6 proteins were associated with MPO-ANCA positivity, and 7 proteins were associated with PR3-ANCA positivity. Conclusion. To our knowledge, this is the first study to identify protein markers preceding symptom onset in AAV patients. These findings set the stage for further research into the underlying cellular and molecular mechanisms in the pathogenesis of AAV and the diversification of patients into PR3-ANCA+ and MPO-ANCA+ subphenotypes.
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| 25. |
- Burkhardt, H., et al.
(författare)
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Epitope-specific recognition of type II collagen by rheumatoid arthritis antibodies is shared with recognition by antibodies that are arthritogenic in collagen-induced arthritis in the mouse
- 2002
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 46:9, s. 2339-2348
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To analyze the fine specificity of IgG autoantibodies in sera from rheumatoid arthritis (RA) patients for type II collagen (CII) epitopes that are arthritogenic in collagen-induced arthritis (CIA), a relevant murine model of RA. METHODS: For enzyme-linked immunosorbent assay (ELISA) analysis of conformation-dependent autoantibody binding, recombinant chimeric collagens that harbor the respective CII epitopes as an insertion within the frame of a constant type X collagen triple helix were constructed. In addition, synthetic peptides mimicking the native collagen structures were applied for the first time in the ELISA assessment of humoral CII autoimmunity. RESULTS: The pathogenicity of IgG responses to certain CII determinants in CIA was demonstrated by arthritis development in BALB/c mice upon the combined transfer of 2 mouse monoclonal antibodies specific for precisely mapped conformational CII epitopes (amino acid residues 359-369 [C1(III)] and 551-564 [J1]), whereas antibodies to another epitope (F4) were not arthritogenic. To test whether human autoimmune responses are similarly directed to these conserved CII determinants, serum IgG was analyzed. The prevalence of sera with increased IgG binding to the C1(III) epitope was significantly higher in RA compared with sera from healthy donors or from patients with other rheumatic conditions, e.g., osteoarthritis (OA), systemic lupus erythematosus (SLE), or relapsing polychondritis (RP), whereas levels of antibodies specific for the nonarthritogenic F4 epitope were associated with OA rather than RA. CONCLUSION: Autoimmunity to CII, although detectable in different rheumatic conditions, differs in fine specificity between distinct disease entities. In RA, in contrast to degenerative joint disease, RP, and SLE, autoantibody responses are directed to an evolutionary conserved CII structure that is also targeted by pathogenic autoimmune responses in murine models of arthritis.
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