| 1. |
- Alping, Peter, et al.
(författare)
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Validation of the Swedish Multiple Sclerosis Register Further Improving a Resource for Pharmacoepidemiologic Evaluations
- 2019
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Ingår i: Epidemiology. - : Lippincott Williams & Wilkins. - 1044-3983 .- 1531-5487. ; 30:2, s. 230-233
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Multiple Sclerosis Register is a national register monitoring treatment and clinical course for all Swedish multiple sclerosis (MS) patients, with high coverage and close integration with the clinic. Despite its great value for epidemiologic research, it has not previously been validated. In this brief report, we summarize a large validation of >3,000 patients in the register using clinical chart review in the context of the COMBAT-MS study. While further improving the data quality for a central cohort of patients available for future epidemiologic research, this study also allowed us to estimate the accuracy and completeness of the register data.
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| 2. |
- Ambrosi, Aurelie, et al.
(författare)
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Development of heart block in children of SSA/SSB-autoantibody-positive women is associated with maternal age and displays a season-of-birth pattern
- 2012
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Ingår i: Annals of the Rheumatic Diseases. - London : BMJ Publishing Group. - 0003-4967 .- 1468-2060. ; 71:3, s. 334-340
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Tidskriftsartikel (refereegranskat)abstract
- Objective Congenital heart block may develop in the fetuses of Ro/SSA-positive and La/SSB-positive mothers. Recurrence rates of only 10-20% despite persisting maternal antibodies indicate that additional factors are critical for the establishment of heart block. The authors investigated the influence of other maternal and fetal factors on heart block development in a Swedish population-based cohort. less thanbrgreater than less thanbrgreater thanMethods The influence of fetal gender, maternal age, parity and time of birth on heart block development was analysed in 145 families, including Ro/La-positive (n=190) and Ro/La-negative (n=165) pregnancies. less thanbrgreater than less thanbrgreater thanResults There was a recurrence rate of 12.1% in Ro/La-positive women, and no recurrence in Ro/La-negative women. Fetal gender and parity did not influence the development of heart block in either group. Maternal age in Ro/La-positive pregnancies with a child affected by heart block was, however, significantly higher than in pregnancies resulting in babies without heart block (pandlt;0.05). Seasonal timing of pregnancy influenced the outcome. Gestational susceptibility weeks 18-24 occurring during January-March correlated with a higher proportion of children with heart block and lower vitamin D levels during the same period in a representative sample of Swedish women and a corresponding higher proportion of children with heart block born in the summer (pandlt;0.02). Maternal age or seasonal timing of pregnancy did not affect the outcome in Ro/La-negative pregnancies. less thanbrgreater than less thanbrgreater thanConclusion This study identifies maternal age and seasonal timing of pregnancy as novel risk factors for heart block development in children of Ro/La-positive women. These observations may be useful for counselling when pregnancy is considered.
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| 3. |
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| 4. |
- Asad, Samina, et al.
(författare)
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HTR1A a Novel Type 1 Diabetes Susceptibility Gene on Chromosome 5p13-q13
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: We have previously performed a genome-wide linkage study in Scandinavian Type 1 diabetes (T1D) families. In the Swedish families, we detected suggestive linkage (LOD less than= 2.2) to the chromosome 5p13-q13 region. The aim of our study was to investigate the linked region in search for possible T1D susceptibility genes. Methodology/Principal Findings: Microsatellites were genotyped in the Scandinavian families to fine-map the previously linked region. Further, SNPs were genotyped in Swedish and Danish families as well as Swedish sporadic cases. In the Swedish families we detected genome-wide significant linkage to the 5-hydroxytryptamine receptor 1A (HTR1A) gene (LOD 3.98, pless than9.8x10(-6)). Markers tagging two separate genes; the ring finger protein 180 (RNF180) and HTR1A showed association to T1D in the Swedish and Danish families (pless than0.002, pless than0.001 respectively). The association was not confirmed in sporadic cases. Conditional analysis indicates that the primary association was to HTR1A. Quantitative PCR show that transcripts of both HTR1A and RNF180 are present in human islets of Langerhans. Moreover, immunohistochemical analysis confirmed the presence of the 5-HTR1A protein in isolated human islets of Langerhans as well as in sections of human pancreas. Conclusions: We have identified and confirmed the association of both HTR1A and RFN180, two genes in high linkage disequilibrium (LD) to T1D in two separate family materials. As both HTR1A and RFN180 were expressed at the mRNA level and HTR1A as protein in human islets of Langerhans, we suggest that HTR1A may affect T1D susceptibility by modulating the initial autoimmune attack or either islet regeneration, insulin release, or both.
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| 5. |
- Badam, Tejaswi V. S., et al.
(författare)
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A validated generally applicable approach using the systematic assessment of disease modules by GWAS reveals a multi-omic module strongly associated with risk factors in multiple sclerosis
- 2021
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Ingår i: BMC Genomics. - : BioMed Central. - 1471-2164. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: There exist few, if any, practical guidelines for predictive and falsifiable multi-omic data integration that systematically integrate existing knowledge. Disease modules are popular concepts for interpreting genome-wide studies in medicine but have so far not been systematically evaluated and may lead to corroborating multi-omic modules. Result: We assessed eight module identification methods in 57 previously published expression and methylation studies of 19 diseases using GWAS enrichment analysis. Next, we applied the same strategy for multi-omic integration of 20 datasets of multiple sclerosis (MS), and further validated the resulting module using both GWAS and risk-factor-associated genes from several independent cohorts. Our benchmark of modules showed that in immune-associated diseases modules inferred from clique-based methods were the most enriched for GWAS genes. The multi-omic case study using MS data revealed the robust identification of a module of 220 genes. Strikingly, most genes of the module were differentially methylated upon the action of one or several environmental risk factors in MS (n = 217, P = 10− 47) and were also independently validated for association with five different risk factors of MS, which further stressed the high genetic and epigenetic relevance of the module for MS. Conclusions: We believe our analysis provides a workflow for selecting modules and our benchmark study may help further improvement of disease module methods. Moreover, we also stress that our methodology is generally applicable for combining and assessing the performance of multi-omic approaches for complex diseases.
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| 6. |
- 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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| 7. |
- Biström, Martin, et al.
(författare)
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Epstein-Barr virus infection after adolescence and Human herpesvirus 6A as risk factors for multiple sclerosis
- 2021
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Ingår i: European Journal of Neurology. - : Blackwell Publishing. - 1351-5101 .- 1468-1331. ; 28:2, s. 579-586
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Infections with human herpesvirus 6A (HHV-6A) and Epstein–Barr virus (EBV) have been linked to multiple sclerosis (MS) development. For EBV, late infection has been proposed as a risk factor, but serological support is lacking. The objective of this study was to investigate how age affects the EBV and HHV-6A associated risks of developing MS.Methods: In this nested case–control study, Swedish biobanks were accessed to find pre-symptomatically collected blood samples from 670 individuals who later developed relapsing MS and 670 matched controls. A bead-based multiplex assay was used to determine serological response against EBV and HHV-6A. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals.Results: Seropositivity against EBV exhibited a pattern where associations switched from a decreased risk of developing MS in the group below 20 years of age to an increased risk amongst individuals aged 20–29 and 30–39 years (p for trend 0.020). The age of transition was estimated to be 18.8 years. In contrast, HHV-6A was associated with increased MS risk in all age groups (total cohort odds ratio 2.1, 95% confidence interval 1.6–2.7).Conclusions: This study suggests EBV infection after adolescence and age independent HHV-6A infection as risk factors for MS.
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| 8. |
- Carlström, Karl E., et al.
(författare)
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Therapeutic efficacy of dimethyl fumarate in relapsing-remitting multiple sclerosis associates with ROS pathway in monocytes
- 2019
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 10:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Dimethyl fumarate (DMF) is a first-line-treatment for relapsing-remitting multiple sclerosis (RRMS). The redox master regulator Nrf2, essential for redox balance, is a target of DMF, but its precise therapeutic mechanisms of action remain elusive. Here we show impact of DMF on circulating monocytes and T cells in a prospective longitudinal RRMS patient cohort. DMF increases the level of oxidized isoprostanes in peripheral blood. Other observed changes, including methylome and transcriptome profiles, occur in monocytes prior to T cells. Importantly, monocyte counts and monocytic ROS increase following DMF and distinguish patients with beneficial treatment-response from non-responders. A single nucleotide polymorphism in the ROS-generating NOX3 gene is associated with beneficial DMF treatment-response. Our data implicate monocyte-derived oxidative processes in autoimmune diseases and their treatment, and identify NOX3 genetic variant, monocyte counts and redox state as parameters potentially useful to inform clinical decisions on DMF therapy of RRMS.
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| 9. |
- Delli, Ahmed, et al.
(författare)
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Zinc Transporter 8 Autoantibodies and Their Association With SLC30A8 and HLA-DQ Genes Differ Between Immigrant and Swedish Patients With Newly Diagnosed Type 1 Diabetes in the Better Diabetes Diagnosis Study
- 2012
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 61:10, s. 2556-2564
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Tidskriftsartikel (refereegranskat)abstract
- We examined whether zinc transporter 8 autoantibodies (ZnT8A; arginine ZnT8-RA, tryptophan ZnT8-WA, and glutamine ZnT8-QA variants) differed between immigrant and Swedish patients due to different polymorphisms of SLC30A8, HLA-DQ, or both. Newly diagnosed autoimmune (andgt;= 1 islet autoantibody) type 1 diabetic patients (n = 2,964, andlt;18 years, 55% male) were ascertained in the Better Diabetes Diagnosis study. Two subgroups were identified: Swedes (n = 2,160, 73%) and immigrants (non-Swedes; n = 212, 7%). Non-Swedes had less frequent ZnT8-WA (38%) than Swedes (50%), consistent with a lower frequency in the non-Swedes (37%) of SLC30A8 CT+TT (RW+WW) genotypes than in the Swedes (54%). ZnT8-RA (57 and 58%, respectively) did not differ despite a higher frequency of CC (RR) genotypes in non-Swedes (63%) than Swedes (46%). We tested whether this inconsistency was due to HLA-DQ as 2/X (2/2; 2/y; y is anything but 2 or 8), which was a major genotype in non-Swedes (40%) compared with Swedes (14%). In the non-Swedes only, 2/X (2/2; 2/y) was negatively associated with ZnT8-WA and ZnT8-QA but not ZnT8-RA. Molecular simulation showed nonbinding of the relevant ZnT8-R peptide to DQ2, explaining in part a possible lack of tolerance to ZnT8-R. At diagnosis in non-Swedes, the presence of ZnT8-RA rather than ZnT8-WA was likely due to effects of HLA-DQ2 and the SLC30A8 CC (RR) genotypes.
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| 10. |
- Grut, Viktor, et al.
(författare)
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Cytomegalovirus seropositivity is associated with reduced risk of multiple sclerosis : a presymptomatic case-control study
- 2021
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Ingår i: European Journal of Neurology. - : Blackwell Publishing. - 1351-5101 .- 1468-1331. ; 28:9, s. 3072-3079
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epstein-Barr virus (EBV) and Human herpesvirus 6A (HHV-6A) are associated with increased risk of multiple sclerosis (MS). Conversely, infection with Cytomegalovirus (CMV) has been suggested to reduce the risk of MS but supporting data from presymptomatic studies are lacking. Here, we sought to increase the understanding of CMV in MS aetiology.METHODS: We performed a nested case-control study with presymptomatically collected blood samples identified through cross-linkage of MS registries and Swedish biobanks. Serological antibody response against CMV, EBV and HHV-6A was determined using a bead-based multiplex assay. Odds ratio (OR) with 95 % confidence intervals (CI) for CMV seropositivity as risk factor for MS was calculated by conditional logistic regression and adjusted for EBV and HHV-6A seropositivity. Potential interactions on the additive scale were analysed by calculating attributable proportion due to interaction (AP).RESULTS: Serum samples from 670 pairs of matched cases and controls were included. CMV seropositivity was associated with a reduced risk for MS (OR = 0.70, 95% CI 0.56-0.88, p = 0.003). Statistical interactions on the additive scale were observed between seronegativity for CMV and seropositivity against HHV-6A (AP 0.34, 95% CI 0.06-0.61) and EBV antigen EBNA-1 (amino acid 385-420) at age 20-39 years (AP 0.37, 95% CI 0.09-0.65).CONCLUSIONS: CMV seropositivity is associated with a decreased risk for MS. The protective role for CMV infection in MS aetiology is further supported by the interactions between CMV seronegativity and EBV and HHV-6A seropositivity.
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