| 1. |
- Bairkdar, Majd, et al.
(författare)
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Incidence and prevalence of systemic sclerosis globally : A comprehensive systematic review and meta-analysis
- 2021
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Ingår i: Rheumatology (United Kingdom). - : Oxford University Press (OUP). - 1462-0324 .- 1462-0332. ; 60:7, s. 3121-3133
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Forskningsöversikt (refereegranskat)abstract
- Objectives: We aimed to conduct a systematic review and meta-analysis on the incidence and prevalence of SSc covering the entire literature. Methods: This study followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement of 2009. We conducted a systematic search in MEDLINE, Web of Science and Embase to identify articles reporting incidence and/or prevalence of SSc. Two authors conducted the search, reviewed articles for inclusion and extracted relevant data. We used random-effects models to estimate the pooled prevalence and incidence of SSc and performed subgroup analyses by sex, case definition and region to investigate heterogeneity. We explored the association between calendar period and reported estimates using meta-regression. Results: Among 6983 unique records identified, we included 61 studies of prevalence and 39 studies of incidence in the systematic review. The overall pooled prevalence of SSc was 17.6 (95% CI 15.1, 20.5) per 100 000 and the overall pooled incidence rate of SSc was 1.4 (95% CI 1.1, 1.9) per 100 000 person-years. We observed significant regional variations in reported estimates; studies conducted in North America reported considerably higher estimates than other regions. The pooled incidence and prevalence in women were five times higher than in men. More recent studies reported higher estimates than older ones. Conclusion: In this comprehensive review of the incidence and prevalence of SSc across the world, there was large heterogeneity among estimates, which should be taken into consideration when interpreting the results.
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| 2. |
- Bairkdar, Majd, et al.
(författare)
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Survival in Swedish patients with systemic sclerosis : A nationwide population-based matched cohort study
- 2023
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Ingår i: Rheumatology (United Kingdom). - : Oxford University Press (OUP). - 1462-0324 .- 1462-0332. ; 62:3, s. 1170-1178
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To conduct the first-ever nationwide, population-based cohort study investigating survival patterns of all patients with incident SSc in Sweden compared with matched individuals from the Swedish general population. Methods: We used the National Patient Register to identify patients with incident SSc diagnosed between 2004 and 2015 and the Total Population Register to identify comparators (1:5), matched on sex, birth year and residential area. We followed them until death, emigration or the end of 2016. Follow-up of the general population comparators started the same date as their matched patients were included. We estimated all-cause survival using the Kaplan-Meier method, crude mortality rates and hazard ratios (HRs) using flexible parametric models. Results: We identified 1139 incident patients with SSc and 5613 matched comparators. The median follow-up was 5.0 years in patients with SSc and 6.0 years for their comparators. During follow-up, 268 deaths occurred in patients with SSc and 554 in their comparators. The 5-year survival was 79.8% and the 10-year survival was 67.7% among patients with SSc vs 92.9% and 84.8%, respectively, for the comparators (P < 0.0001). The mortality rate in patients with SSc was 42.1 per 1000 person-years and 15.8 per 1000 person-years in their comparators, corresponding to an HR of 3.7 (95% CI 2.9, 4.7) at the end of the first year of follow-up and 2.0 (95% CI 1.4, 2.8) at the end of the follow-up period. Conclusion: Despite advances in understanding the disease and in diagnostic methods over the past decades, survival is still severely impacted in Swedish patients diagnosed with SSc between 2004 and 2015.
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| 3. |
- Beecham, Ashley H, et al.
(författare)
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Analysis of immune-related loci identifies 48 new susceptibility variants for multiple sclerosis.
- 2013
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 45:11, s. 1353-60
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Tidskriftsartikel (refereegranskat)abstract
- Using the ImmunoChip custom genotyping array, we analyzed 14,498 subjects with multiple sclerosis and 24,091 healthy controls for 161,311 autosomal variants and identified 135 potentially associated regions (P < 1.0 × 10(-4)). In a replication phase, we combined these data with previous genome-wide association study (GWAS) data from an independent 14,802 subjects with multiple sclerosis and 26,703 healthy controls. In these 80,094 individuals of European ancestry, we identified 48 new susceptibility variants (P < 5.0 × 10(-8)), 3 of which we found after conditioning on previously identified variants. Thus, there are now 110 established multiple sclerosis risk variants at 103 discrete loci outside of the major histocompatibility complex. With high-resolution Bayesian fine mapping, we identified five regions where one variant accounted for more than 50% of the posterior probability of association. This study enhances the catalog of multiple sclerosis risk variants and illustrates the value of fine mapping in the resolution of GWAS signals.
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| 4. |
- Berglund, Daniel, et al.
(författare)
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Measures of Additive Interactionand Effect Direction
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Measures for additive interaction are defined using risk ratios. These ratios need to be modeled so that all combinations of the exposures are harmful, as the scale between protective and harmful factors differs. This remodeling is referred to as recoding. Previously, recoding has been thought of as random. In this paper, we will examine and discuss the impact of recoding in studies with small effect sizes, such as genome wide association studies, and the impact recoding has on significance testing.
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| 5. |
- Berglund, Daniel
(författare)
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Models for Additive and Sufficient Cause Interaction
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis is to develop and explore models in, and related to, the sufficient cause framework, and additive interaction. Additive interaction is closely connected with public health interventions and can be used to make inferences about the sufficient causes in order to find the mechanisms behind an outcome, for instance a disease.In paper A we extend the additive interaction, and interventions, to include continuous exposures. We show that there does not exist a model that does not lead to inconsistent conclusions about the interaction.The sufficient cause framework can also be expressed using Boolean functions, which is expanded upon in paper B. In this paper we define a new model based on the multifactor potential outcome model (MFPO) and independence of causal influence models (ICI).In paper C we discuss the modeling and estimation of additive interaction in relation to if the exposures are harmful or protective conditioned on some other exposure. If there is uncertainty about the effects direction there can be errors in the testing of the interaction effect.
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| 6. |
- Berglund, Daniel, et al.
(författare)
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On the Existence of Suitable Models for Additive Interaction with Continuous Exposures
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Additive interaction can be of importance for public health interventions and it is commonly defined using binary exposures. There has been expansions of the models to also include continuous exposures, which could lead to better and more precise estimations of the effect of interventions. In this paper we define the intervention for a continuous exposure as a monotonic function. Based on this function for the interventions we prove that there is no model for estimating additive interactions with continuous exposures for which it holds that; (i) both exposures have marginal effects and no additive interaction on the exposure level for both exposures, (ii) neither exposure has marginal effect and there is additive interaction between the exposures. We also show that a logistic regression model for continuous exposures will always produce additive interaction if both exposures have marginal effects.
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| 7. |
- Essner, Ann, Medicine Doktor, PhD, et al.
(författare)
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Physical activity and sport-specific training patterns in Swedish sporting and working trial dogs : A questionnaire survey
- 2022
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Ingår i: Frontiers in Veterinary Science. - : Frontiers Media S.A.. - 2297-1769. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To explore physical activity patterns, including conditioning exercise and sport-specific training, and management routines utilized by handlers of Swedish sporting and working dogs participating in agility, obedience, rally obedience and working trial disciplines.Procedures: Dog handlers provided information on competition-level dogs through an internet-based cross-sectional and descriptive survey on physical activity, sport-specific training and management. Results are reported overall and stratified by participation in specific disciplines.Results: We received 1615 replies to the questionnaire. After data cleaning, 1582 dogs (98%) remained for the analysis. Of these, 430 participated in agility, 790 in obedience, 596 in rally obedience, and 847 dogs had competed in a working trial, i.e., messenger, protection, search or tracking. Number of disciplines performed by each dog varied between one and five. Most common was participation in one (n = 767, 48%) or two (n = 541, 34%) disciplines. Out of the dogs competing in one discipline, 38% (n = 294) were considered to be specialized as they actively trained only that discipline for >= 10 months per year. The vast majority of the dogs (n = 1129, 71%) received more than 1 h of daily physical activity, e.g., walks, and only n = 51 (3%) were never exercised off-leash. Preferred self-selected gait was trot (n = 907, 57%) and gallop (n = 499, 32%). A fifth (n = 319, 20%) never played with other dogs. The majority (n = 1328, 84%) received more than 1 h of vigorous physical conditioning exercise per week. Almost three quarters (n = 1119, 71%) participated in physical conditioning exercise. Two thirds (n = 953, 60%) participated in at least 3 h of sport-specific training per week and only a very small portion (n = 35, 2%) trained their specific discipline less than once per week. Median total work load, i.e., all daily physical activity, vigorous physical conditioning exercise and sport-specific training, was 16.5 h per week.Conclusion and clinical relevance: We observe physical activity at moderate to high durations and moderate to vigorous intensities among Swedish sporting and working trial dogs. Most dogs received physical conditioning exercise, but not all dogs were warmed up before training and competition. Our study provides veterinary professionals and dog trainers with valuable insights on the physical exposures and management routines of sporting and working trial dogs.
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| 8. |
- Folkersen, Lasse, et al.
(författare)
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Integration of known DNA, RNA and protein biomarkers provides prediction of anti-TNF response in rheumatoid arthritis : results from the COMBINE study.
- 2016
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Ingår i: Molecular Medicine. - : Springer Science and Business Media LLC. - 1076-1551 .- 1528-3658. ; 22, s. 322-328
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In rheumatoid arthritis (RA) several recent efforts have sought to discover means of predicting which patients would benefit from treatment. However, results have been discrepant with few successful replications. Our objective was to build a biobank with DNA, RNA and protein measurements to test the claim that the current state-of-the-art precision medicine will benefit RA patients.METHODS: We collected 451 blood samples from 61 healthy individuals and 185 RA patients initiating treatment, before treatment initiation and at a 3 month follow-up time. All samples were subjected to high-throughput RNA sequencing, DNA genotyping, extensive proteomics and flow cytometry measurements, as well as comprehensive clinical phenotyping. Literature review identified 2 proteins, 52 single-nucleotide polymorphisms (SNPs) and 72 gene-expression biomarkers that had previously been proposed as predictors of TNF inhibitor response (∆DAS28-CRP).RESULTS: From these published TNFi biomarkers we found that 2 protein, 2 SNP and 8 mRNA biomarkers could be replicated in the 59 TNF initiating patients. Combining these replicated biomarkers into a single signature we found that we could explain 51% of the variation in ∆DAS28-CRP. This corresponds to a sensitivity of 0.73 and specificity of 0.78 for the prediction of three month ∆DAS28-CRP better than -1.2.CONCLUSIONS: The COMBINE biobank is currently the largest collection of multi-omics data from RA patients with high potential for discovery and replication. Taking advantage of this we surveyed the current state-of-the-art of drug-response stratification in RA, and identified a small set of previously published biomarkers available in peripheral blood which predicts clinical response to TNF blockade in this independent cohort.
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| 9. |
- Lourdudoss, Cecilia, et al.
(författare)
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Dietary Intake of Polyunsaturated Fatty Acids and Pain in Spite of Inflammatory Control Among Methotrexate-Treated Early Rheumatoid Arthritis Patients.
- 2018
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Ingår i: Arthritis care & research. - : Wiley. - 2151-464X .- 2151-4658. ; 70:2, s. 205-212
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate potential associations between dietary intake of polyunsaturated fatty acids (FAs) and pain patterns in early rheumatoid arthritis (RA) patients after 3 months of methotrexate (MTX) treatment.METHODS: We included 591 early RA patients with MTX monotherapy from a population-based prospective case-control study, the Epidemiological Investigation of Rheumatoid Arthritis. Dietary data on polyunsaturated FAs (food frequency questionnaires) were linked with data on unacceptable pain (visual analog scale [VAS] >40 mm), noninflammatory/refractory pain (VAS >40 mm and C-reactive protein [CRP] level <10 mg/liter), and inflammatory pain (VAS >40 mm and CRP level >10 mg/liter) after 3 months. Statistical analysis included logistic regression.RESULTS: After 3 months of MTX treatment, 125 patients (21.2%) had unacceptable pain, of which 92 patients had refractory pain, and 33 patients had inflammatory pain. Omega-3 FA intake was inversely associated with unacceptable pain and refractory pain (odds ratio [OR] 0.57 [95% confidence interval (95% CI) 0.35-0.95] and OR 0.47 [95% CI 0.26-0.84], respectively). The omega-6:omega-3 FA ratio, but not omega-6 FA alone, was directly associated with unacceptable pain and refractory pain (OR 1.70 [95% CI 1.03-2.82] and OR 2.33 [95% CI 1.28-4.24], respectively). Furthermore, polyunsaturated FAs were not associated with either inflammatory pain or CRP level and erythrocyte sedimentation rate at followup. Omega-3 FA supplementation was not associated with any pain patterns.CONCLUSION: Omega-3 FA was inversely associated with, and the omega-6:omega-3 FA ratio was directly associated with, unacceptable and refractory pain, but not with inflammatory pain or systemic inflammation. The inverse association between omega-3 FA and refractory pain may have a role in pain suppression in RA.
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| 10. |
- Manivel, Vivek Anand, et al.
(författare)
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Anticollagen type II antibodies are associated with an acute onset rheumatoid arthritis phenotype and prognosticate lower degree of inflammation during 5 years follow-up
- 2017
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 76:9, s. 1529-1536
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveAntifibrillar collagen type II (anti-CII) antibody-positive patients with rheumatoid arthritis (RA) have early but not late signs of increased inflammation and joint erosions. We wanted to replicate this in a large RA cohort, and to relate to human leukocyte antigen (HLA)-DRB1* alleles.MethodsAnti-CII and anti-cyclic citrullinated peptide (CCP)2 were measured at baseline in 773 patients with RA from the Swedish Epidemiological Investigation in Rheumatoid Arthritis (EIRA) study with clinical follow-up data from the Swedish Rheumatology Quality Register (SRQ) registry, and 1476 with HLA-DRB1* information. Comparisons were done concerning C reactive protein (CRP), erythrocyte sedimentation rate (ESR), tender joint count (TJC), swollen joint count (SJC), Disease Activity Score encompassing 28 joints based on ESR (DAS28), DAS28CRP, pain-Visual Analogue Scale (VAS), global-VAS and Health Assessment Questionnaire Score (HAQ) at eight occasions during 5 years, and association with HLA-DRB1* alleles.ResultsAnti-CII associated with elevated CRP, ESR, SJC, DAS28 and DAS28CRP at diagnosis and up to 6 months, whereas anti-CCP2 associated with SJC and DAS28 from 6 months to 5 years, but not earlier. The anti-CII-associated phenotype was strong, and predominated in anti-CII/anti-CCP2 double-positive patients. Anti-CII was associated with improvements in CRP, ESR, SJC, TJC and DAS28, whereas anti-CCP2 was associated with deteriorations in SJC and DAS28 over time. Anti-CII-positive patients achieved European League Against Rheumatism good or moderate response more often than negative patients. Anti-CII was positively associated with HLA-DRB1*01 and HLA-DRB1*03, with significant interaction, and double-positive individuals had >14 times higher mean anti-CII levels than HLA double negatives. Whereas smoking was associated with elevated anti-CCP2 levels, smokers had lower anti-CII levels.ConclusionsAnti-CII seropositive RA represents a distinct phenotype, in many respects representing the converse to the clinical, genetic and smoking associations described for anticitrullinated protein peptide autoantibodies. Although not diagnostically useful, early anti-CII determinations predict favourable inflammatory outcome in RA.
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| 11. |
- Pertsinidou, Eleftheria, et al.
(författare)
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In early rheumatoid arthritis, anticitrullinated peptide antibodies associate with low number of affected joints and rheumatoid factor associates with systemic inflammation
- 2024
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ Publishing Group Ltd. - 0003-4967 .- 1468-2060. ; 83:3, s. 277-287
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate how individual rheumatoid arthritis (RA) autoantibodies associate with individual signs and symptoms at the time of RA diagnosis.Methods: IgA, IgG, IgM rheumatoid factor (RF), antibodies against cyclic citrullinated peptide version 2 (anti-CCP2) and 16 individual antibodies against citrullinated protein (ACPA) reactivities were analysed centrally in baseline sera from 1600 patients with RA classified according to the 1987 American College of Rheumatology (ACR) criteria. These results were related to C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), number of swollen and tender joints (SJC and TJC), 28-joint disease activity scores (DAS28 and DAS28CRP), global disease activity evaluated by the patients and Health Assessment Questionnaire, all obtained at baseline.Results: Individually, all autoantibodies except immunoglobulin G (IgG) RF associated with low SJC and TJC and with high ESR. In IgM RF-negative patients, ACPA associated strictly with low number of swollen and tender joints. This association persisted in multiple regression and stratified analyses where IgM and IgA RF instead associated with inflammation expressed as ESR. Among subjects without any ACPA peptide reactivity, there was no association between RF isotypes and ESR. The effect of RF on ESR increased with the number of ACPA reactivities, especially for IgM RF. In patients fulfilling the 1987 ACR criteria without taking RF into account, associations between IgM RF and high ESR, as well as between ACPA and low joint counts, remained.Conclusion: Whereas ACPA associate with low counts of affected joints in early RA, RF associates with elevated measures of systemic inflammation in an ACPA-dependent manner. This latter finding corroborates in vitro models of ACPA and RF in immune complex-induced inflammation. These phenotypic associations are independent of classification criteria.
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| 12. |
- Song, Jie, et al.
(författare)
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Similar familial risk in multiple sclerosis subgroups
- 2017
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Ingår i: Multiple Sclerosis. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1352-4585 .- 1477-0970.
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Tidskriftsartikel (refereegranskat)abstract
- Background: A subgroup of patients diagnosed with multiple sclerosis (MS) present with no oligoclonal bands (OCB) in the cerebrospinal fluid (CSF). Several studies report different clinical characteristics and genetic associations between the two groups. Objective: To investigate whether the OCB negative subgroup has a distinct etiology from band positive MS. Methods: Using nationwide registers to estimate familial risks, which reflect the genetic contribution of a disease. Results: Odds ratios of MS were similar for relatives to band positive and negative patients. Conclusion: From the perspective of familial liability, MS without OCB is etiologically closely related to the dominant subgroup of OCB positive MS.
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| 13. |
- Terao, Chikashi, et al.
(författare)
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Distinct HLA Associations with Rheumatoid Arthritis Subsets Defined by Serological Subphenotype
- 2019
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Ingår i: American Journal of Human Genetics. - : Cell Press. - 0002-9297 .- 1537-6605. ; 105:3, s. 616-624
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Tidskriftsartikel (refereegranskat)abstract
- Rheumatoid arthritis (RA) is the most common immune-mediated arthritis. Anti-citrullinated peptide antibodies (ACPA) are highly specific to RA and assayed with the commercial CCP2 assay. Genetic drivers of RA within the MHC are different for CCP2-positive and -negative subsets of RA, particularly at HLA-DRB1. However, aspartic acid at amino acid position 9 in HLA-B (Bpos-9) increases risk to both RA subsets. Here we explore how individual serologies associated with RA drive associations within the MHC. To define MHC differences for specific ACPA serologies, we quantified a total of 19 separate ACPAs in RA-affected case subjects from four cohorts (n = 6,805). We found a cluster of tightly co-occurring antibodies (canonical serologies, containing CCP2), along with several independently expressed antibodies (non-canonical serologies). After imputing HLA variants into 6,805 case subjects and 13,467 control subjects, we tested associations between the HLA region and RA subgroups based on the presence of canonical and/or non-canonical serologies. We examined CCP2(+) and CCP2(−) RA-affected case subjects separately. In CCP2(−) RA, we observed that the association between CCP2(−) RA and Bpos-9 was derived from individuals who were positive for non-canonical serologies (omnibus_p = 9.2 × 10−17). Similarly, we observed in CCP2(+) RA that associations between subsets of CCP2(+) RA and Bpos-9 were negatively correlated with the number of positive canonical serologies (p = 0.0096). These findings suggest unique genetic characteristics underlying fine-specific ACPAs, suggesting that RA may be further subdivided beyond simply seropositive and seronegative.
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| 14. |
- Westerlind, Helga, et al.
(författare)
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Anti-Citrullinated Protein Antibody Specificities, Rheumatoid Factor Isotypes, and Incident Cardiovascular Events in Patients With Rheumatoid Arthritis
- 2020
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Ingår i: Arthritis & Rheumatology. - : John Wiley & Sons. - 2326-5191 .- 2326-5205. ; 72:10, s. 1658-1667
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the relationship between anti–citrullinated protein antibodies (ACPAs), specific ACPA subspecificities, rheumatoid factor (RF) isotypes, and incident cardiovascular (CV) events in patients with rheumatoid arthritis (RA).Methods Serum samples from Swedish patients with new-onset RA (diagnosed within 1 year of symptom onset between 1996 and 2009) were centrally typed for anti–cyclic citrullinated peptide 2 (anti-CCP2) antibodies, 20 ACPA subspecificities, and RF isotypes. Patients were followed up longitudinally in nationwide registers to monitor the occurrence of acute coronary syndrome (ACS), stroke, CV-related death, and major adverse CV events (MACE). The association between each serologic marker and CV outcome, and the impact of adjustment for the Disease Activity Score in 28 joints (DAS28), smoking status, and income at baseline, were assessed using Cox proportional hazards models. In addition, associations of serologic markers with all-cause mortality were explored.Results In total, 2,814 patients with RA were included in the study. The median follow-up was 13 years, during which the CV end points of ACS, stroke, or CV-related death were reported to occur in 375 patients. Occurrence and/or levels of anti-CCP2 were associated with risk of incident ACS (hazard ratio [HR] 1.46, 95% confidence interval [95% CI] 1.03–2.06), stroke (HR 1.47, 95% CI 1.03–2.10), CV-related death (P = 0.024 for association with anti-CCP2 levels), and MACE (HR 1.34, 95% CI 1.06–1.70). Similarly, an association with the number of ACPA subspecificities was observed; however, this could not be attributed to any individual or group of ACPA subspecificities. Presence of IgM-RF was associated with all CV end points except ACS, and IgA-RF was exclusively associated with CV-related death. Adjustment for smoking status, income, and DAS28 scores decreased most of the HRs, whereas IgA-RF remained associated with CV-related death (HR 1.61, 95% CI 1.05–2.48). All of the assessed serologic makers were associated with all-cause mortality.Conclusion RF isotypes and ACPAs are associated with future CV events in patients with RA. ACPA levels and number of subspecificities seem more important than the occurrence of particular subspecificities, and these associations were not explained by a history of ever smoking.
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| 15. |
- Westerlind, Helga, et al.
(författare)
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Dense genotyping of immune-related loci identifies HLA variants associated with increased risk of collagenous colitis.
- 2017
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Ingår i: Gut. - : BMJ Publishing Group Ltd. - 0017-5749 .- 1468-3288. ; 66:3, s. 421-428
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Collagenous colitis (CC) is a major cause of chronic non-bloody diarrhoea, particularly in the elderly female population. The aetiology of CC is unknown, and still poor is the understanding of its pathogenesis. This possibly involves dysregulated inflammation and immune-mediated reactions in genetically predisposed individuals, but the contribution of genetic factors to CC is underinvestigated. We systematically tested immune-related genes known to impact the risk of several autoimmune diseases for their potential CC-predisposing role.DESIGN: Three independent cohorts of histologically confirmed CC cases (N=314) and controls (N=4299) from Sweden and Germany were included in a 2-step association analysis. Immunochip and targeted single nucleotide polymorphism (SNP) genotype data were produced, respectively, for discovery and replication purposes. Classical human leucocyte antigen (HLA) variants at 2-digit and 4-digit resolution were obtained via imputation from single marker genotypes. SNPs and HLA variants passing quality control filters were tested for association with CC with logistic regression adjusting for age, sex and country of origin.RESULTS: Forty-two markers gave rise to genome-wide significant association signals, all contained within the HLA region on chromosome 6 (best p=4.2×10(-10) for SNP rs4143332). Among the HLA variants, most pronounced risk effects were observed for 8.1 haplotype alleles including DQ2.5, which was targeted and confirmed in the replication data set (p=2.3×10(-11); OR=2.06; 95% CI (1.67 to 2.55) in the combined analysis).CONCLUSIONS: HLA genotype associates with CC, thus implicating HLA-related immune mechanisms in its pathogenesis.
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| 16. |
- Westerlind, Helga, et al.
(författare)
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Incidence and prevalence of systemic sclerosis in Sweden, 2004–2015, a register-based study
- 2022
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Ingår i: Seminars in Arthritis and Rheumatism. - : Elsevier BV. - 0049-0172 .- 1532-866X. ; 53
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: we aim to present an in-depth report of the incidence and prevalence of systemic sclerosis (SSc) in Sweden in a nation-wide register-based study covering the entire Swedish population Methods: each individual residing in Sweden is given a unique personal identity number. We linked the National Patient Register and the Total Population Register to identify 1) patients with prevalent SSc on 2015–12–31 and 2) patients with incident SSc during the time period 2004–2015 based on ICD-10 codes. We estimated prevalence and incidence overall and stratified on age, sex, and county. Results: we identified 1774 prevalent cases, median age was 65 years (IQR 19.2) and 84% were women. The point prevalence estimate was 22.7 per 100,000 (95%CI 13.3–32.0). 1139 individuals were newly diagnosed with SSc during 2004–2015 with a median age of 60 years (IQR 20.6) and 80% were women. The mean standardized incidence was 11.9 per 1,000,000 person-years (95%CI 5.1–18.7). The annual incidence remained stable over the study period. Women had five times higher incidence and prevalence than men. The highest prevalence stratified by age strata was observed in the group aged 70–79. Conclusion: SSc incidence and prevalence in Sweden are comparable to estimates from southern Europe, as opposed to the previous assumption of lower occurrence in northern Europe. We further observe that SSc incidence has been rather constant throughout recent years in Sweden with no obvious increase.
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| 17. |
- Westerlind, Helga
(författare)
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Modeling genetic susceptibility to multiple sclerosis
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main aim of this thesis was to investigate genetic and environmental factors and their role in the etiology of Multiple Sclerosis (MS) by using comprehensive registry data or novel computationally intense methods. To date, over 100 genes associated with MS have been identified, but how they interact in the risk for the disease is not yet fully understood. The presence of high prevalence clusters has led researchers to believe that there might be as yet unidentified rare variant involved in the disease etiology. In Paper I, we attempted to search for these rare variants by using a population based linkage approach, estimating haplotypes shared between individuals inherited by descent from some common ancestor. One significant hit was found on chromosome 19, but due to methodological problems the result should be interpreted with caution. MS is commonly attributed high familial risks, decreasing with relatedness, which indicates a large genetic component involved in the disease etiology. In Paper II, nationwide registry data was used to reinvestigate the familial risks and estimate the proportion of genetics and environment contributing to disease etiology. The relative risks estimated were lower than usually reported, with a sibling relative risk of 7.1 and no significant differences between the sexes. The heritability was estimated to be 64% and the environmental 36% with a non-significant shared environmental component of 1%. In Paper III, the women-to-men ratio for MS in Sweden was reinvestigated. MS is a disease more common in women than men, and an increase in the women-to-men ratio has been reported in several countries. However, a report from Sweden did not show this increase in women and Paper III extended this report using data from nationwide registers. An increase among women compared to men was identified, and when comparing against the previous study, an inclusion bias, presumably caused by a higher mortality rate among the oldest men, was identified. One framework used to model complex diseases such as MS is the sufficent cause model, also known as Rothman's pie model. This model hypotehsizes that a disease can be caused by several mechanisms, or pies, each consisting of a set of different factors and when all factors are present they will inevitably cause disease. Paper IV extends this model into a stochastic version and presents an algorithm that can estimate the probability that an a priori suggested mechanism has caused disease in a certain individual. The algorithm showed high classification accuracy on synthetic data; however it needs further investigation of its properties. In conclusion, this thesis revise the familial risks for MS to more moderate levels, with no differences between the sexes, and confirms the global trend of an increasing women-to-men ratio. No rare variants contributing to MS on population level were identified. We also present a probabilitic version of Rothman's pie model, showing promising results on synthetic data.
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| 18. |
- Westerlind, Helga, et al.
(författare)
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New data identify an increasing sex ratio of multiple sclerosis in Sweden
- 2014
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Ingår i: Multiple Sclerosis Journal. - : SAGE Publications (UK and US). - 1352-4585 .- 1477-0970. ; 20:12, s. 1578-1583
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Tidskriftsartikel (refereegranskat)abstract
- Background: An increasing women-to-men ratio in later birth cohorts of patients with multiple sclerosis (MS) has been observed in several populations and has been hypothesised to be due to one or several environmental factors of importance for disease aetiology. However, in a study based on data from the Swedish MS registry (SMSreg) this ratio was recently reported to be rather stable during the 20th century. Objective: The purpose of this study was to reinvestigate the women-to-men ratio in Sweden based on data from all available data sources, including deceased patients. Method: We combined data from the SMSreg with data from national patient registers. Results: In total we obtained information on 19,510 MS patients born 1931-1985, 13,321 women and 6189 men. The women-to-men ratio increased from 1.70 for patients born in the 1930s to 2.67 for patients born in the 1980s. When comparing the coverage of SMSreg to the full data set, a significantly higher proportion of women born 1931-1935 compared to men born in the same period were found in SMSreg, resulting in a sampling bias hiding the increasing sex ratio in the full material. Conclusion: The women-to-men ratio in MS has increased in Sweden during the 20th century similarly to observations in other western countries.
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- Westerlind, Helga, et al.
(författare)
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Siblings of patients with rheumatoid arthritis are at increased risk of acute coronary syndrome
- 2019
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ Publishing Group Ltd. - 0003-4967 .- 1468-2060. ; 78:5, s. 683-687
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate a potential shared susceptibility between rheumatoid arthritis (RA) and acute coronary syndrome (ACS) by estimation of the risk of ACS among full siblings of patients with RA.Methods: By linking nation-wide Swedish registers, we identified a cohort of patients with new-onset RA 1996–2016, age- and sex-matched (5:1) general population comparator subjects, full siblings of RA and comparator subjects, and incident ACS events through 31 December 2016. We used Cox regression to estimate the HR of ACS among patients with RA and the siblings of patients with RA versus the general population, overall and stratified by RA serostatus. We explored the impact of traditional cardiovascular (CV) risk factors on the observed associations.Results: We identified 8109 patients with incident RA, and 11 562 full siblings of these. Compared with the general population, the HR of ACS in RA was 1.46 (95% CI 1.28 to 1.67) and 1.22 (95% CI 1.09 to 1.38) among their siblings. The increased risks seemed confined to seropositive RA (patients: 1.52 [1.30 to 1.79], their siblings: 1.27 [1.10 to 1.46]); no significant risk increase was observed among siblings of patients with seronegative RA (HR 1.13 [95% CI 0.92 to 1.39]). Adjustment for 19 traditional CV risk factors did not appreciably alter these associations.Conclusion: Siblings of patients with RA are at increased risk of ACS, suggesting shared susceptibility between RA and ACS, indicating the need and potential for additional cardio-preventive measures in RA (and their siblings).
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- Westerlind, Helga, et al.
(författare)
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The association between autoantibodies and risk for venous thromboembolic events among patients with rheumatoid arthritis
- 2023
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Ingår i: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 62:6, s. 2106-2112
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To assess the association between venous thromboembolic (VTE) events and autoantibodies, following patients from RA diagnosis, measuring occurrence, levels and collective load of different autoantibodies against post-translational protein modifications, in particular recognizing citrullination (e.g. citrullinated fibrinogen) and RF by isotype. Methods A cohort of 2814 patients with newly diagnosed RA were followed for incident VTE through register linkages. Sera from RA diagnosis were centrally analysed for antibodies to second generation cyclic citrullinated peptides (anti-CCP2), 20 anti-citrullinated protein antibody (ACPA) fine-specificities, antibodies to additional protein modifications (carbamylation and acetylation) and RF by isotype. Association between baseline serology status and future VTE was analysed using Cox regression adjusted for age, sex and calendar period of RA diagnosis, overall and stratified by anti-CCP2 and RF positivity. Results During a median 16 years of follow-up, 213 first-ever VTE events were registered (5.0/1000 person-years). IgG anti-CCP2 (present in 65% of cohort) associated with VTE (hazard ratio [HR] = 1.33, 95% CI: 1.00, 1.78), in a dose-response manner. The risk of VTE increased with number of ACPA fine-specificities. IgM RF, but no other RF isotypes, associated with VTE (HR = 1.38, 95% CI: 1.04, 1.82). The associations were independent from smoking and HLA-DRB1 shared epitope alleles. None of the carbamylated or acetylated antibody reactivities associated with VTE. Conclusion Anti-CCP2, load of ACPA fine-specificities and IgM RF at RA diagnosis are associated with an increased risk of future VTE in RA. Antibodies to citrullinated fibrinogen did not differ substantially from other ACPA fine-specificities. Autoreactivity to other post-translational modifications was not associated with VTE risk.
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- Öberg Sysojev, Anton, et al.
(författare)
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Genome-wide investigation of persistence with methotrexate treatment in early rheumatoid arthritis
- 2024
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Ingår i: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 63:5, s. 1221-1229
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the influence of genetic factors on persistence to treatment of early rheumatoid arthritis (RA) with methotrexate (MTX) monotherapy.Methods: We conducted a genome-wide association study (GWAS) in a sample of 3902 Swedish early RA patients initiating MTX in DMARD-monotherapy as their first ever DMARD. The outcome, short- and long-term persistence to this treatment, was defined as remaining on MTX at one and at three years, respectively, with no additional DMARDs added. As genetic predictors, we investigated individual SNPs, and a polygenic risk score (PRS) based on SNPs associated with RA risk. The SNP-based heritability of persistence was estimated overall and by RA serostatus.Results: No individual SNP reached genome-wide significance (p < 5e-8), neither for persistence at one nor at three years. The RA PRS was not significantly associated with persistence at one (RR = 0.98 (0.96-1.01)) nor three years (RR = 0.96 (0.93-1.00)). The heritability for persistence was estimated to be 0.45 (0.15-0.75) at one year and 0.14 (0-0.40) at three years. Results in seropositive RA were comparable to those in the analysis of RA overall, while heritability estimates and PRS RRs were attenuated towards the null in seronegative RA.Conclusions: Despite being the largest GWAS on an MTX treatment outcome to date, no genome-wide significant associations were detected. The modest heritability observed, coupled with the broad spread of suggestively associated loci, indicate that genetic influence is of polygenic nature. Nevertheless, persistence to MTX monotherapy was lower in patients with a greater genetic disposition, per the PRS, towards RA.
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