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We investigate a 2,000-year genetic transect through Scandinavia spanning the Iron Age to the present, based on 48 new and 249 published ancient genomes and genotypes from 16,638 modern individuals. We find regional variation in the timing and magnitude of gene flow from three sources: the eastern Baltic, the British-Irish Isles, and southern Europe. British-Irish ancestry was widespread in Scandinavia from the Viking period, whereas eastern Baltic ancestry is more localized to Gotland and central Sweden. In some regions, a drop in current levels of external ancestry suggests that ancient immigrants contributed proportionately less to the modern Scandinavian gene pool than indicated by the ancestry of genomes from the Viking and Medieval periods. Finally, we show that a north-south genetic cline that characterizes modern Scandinavians is mainly due to the differential levels of Uralic ancestry and that this cline existed in the Viking Age and possibly earlier.
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Genoma Humano , Humanos , Europa (Continente) , Variación Genética , Países Escandinavos y Nórdicos , Reino Unido , Población Blanca/genética , Población Blanca/historia , Migración HumanaRESUMEN
Although evidence exists for a causal association between 25-hydroxyvitamin D (25(OH)D) serum levels, and multiple sclerosis (MS), the role of variation in vitamin D receptor (VDR) binding in MS is unknown. Here, we leveraged previously identified variants associated with allele imbalance in VDR binding (VDR-binding variant; VDR-BV) in ChIP-exo data from calcitriol-stimulated lymphoblastoid cell lines and 25(OH)D serum levels from genome-wide association studies to construct genetic instrumental variables (GIVs). GIVs are composed of one or more genetic variants that serve as proxies for exposures of interest. Here, GIVs for both VDR-BVs and 25(OH)D were used in a two-sample Mendelian Randomization study to investigate the relationship between VDR binding at a locus, 25(OH)D serum levels, and MS risk. Data for 13,598 MS cases and 38,887 controls of European ancestry from Kaiser Permanente Northern California, Swedish MS studies, and the UK Biobank were included. We estimated the association between each VDR-BV GIV and MS. Significant interaction between a VDR-BV GIV and a GIV for serum 25OH(D) was evidence for a causal association between VDR-BVs and MS unbiased by pleiotropy. We observed evidence for associations between two VDR-BVs (rs2881514, rs2531804) and MS after correction for multiple tests. There was evidence of interaction between rs2881514 and a 25(OH)D GIV, providing evidence of a causal association between rs2881514 and MS. This study is the first to demonstrate evidence that variation in VDR binding at a locus contributes to MS risk. Our results are relevant to other autoimmune diseases in which vitamin D plays a role.
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Esclerosis Múltiple , Humanos , Esclerosis Múltiple/genética , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Alelos , Estudio de Asociación del Genoma Completo , Vitamina D/metabolismo , Calcitriol , Polimorfismo de Nucleótido SimpleRESUMEN
Autoimmune thyroid disease is the most common autoimmune disease and is highly heritable1. Here, by using a genome-wide association study of 30,234 cases and 725,172 controls from Iceland and the UK Biobank, we find 99 sequence variants at 93 loci, of which 84 variants are previously unreported2-7. A low-frequency (1.36%) intronic variant in FLT3 (rs76428106-C) has the largest effect on risk of autoimmune thyroid disease (odds ratio (OR) = 1.46, P = 2.37 × 10-24). rs76428106-C is also associated with systemic lupus erythematosus (OR = 1.90, P = 6.46 × 10-4), rheumatoid factor and/or anti-CCP-positive rheumatoid arthritis (OR = 1.41, P = 4.31 × 10-4) and coeliac disease (OR = 1.62, P = 1.20 × 10-4). FLT3 encodes fms-related tyrosine kinase 3, a receptor that regulates haematopoietic progenitor and dendritic cells. RNA sequencing revealed that rs76428106-C generates a cryptic splice site, which introduces a stop codon in 30% of transcripts that are predicted to encode a truncated protein, which lacks its tyrosine kinase domains. Each copy of rs76428106-C doubles the plasma levels of the FTL3 ligand. Activating somatic mutations in FLT3 are associated with acute myeloid leukaemia8 with a poor prognosis and rs76428106-C also predisposes individuals to acute myeloid leukaemia (OR = 1.90, P = 5.40 × 10-3). Thus, a predicted loss-of-function germline mutation in FLT3 causes a reduction in full-length FLT3, with a compensatory increase in the levels of its ligand and an increased disease risk, similar to that of a gain-of-function mutation.
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Codón sin Sentido/genética , Predisposición Genética a la Enfermedad/genética , Ligandos , Mutación , Tiroiditis Autoinmune/genética , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismo , Alelos , Enfermedades Autoinmunes/genética , Bases de Datos Factuales , Estudio de Asociación del Genoma Completo , Mutación de Línea Germinal , Humanos , Islandia , Intrones/genética , Leucemia Mieloide Aguda , Mutación con Pérdida de Función , Sitios de Empalme de ARN/genética , Reino UnidoRESUMEN
Epstein-Barr virus (EBV) infection has been advocated as a prerequisite for developing multiple sclerosis (MS) and possibly the propagation of the disease. However, the precise mechanisms for such influences are still unclear. A large-scale study investigating the host genetics of EBV serology and related clinical manifestations, such as infectious mononucleosis (IM), may help us better understand the role of EBV in MS pathogenesis. This study evaluates the host genetic factors that influence serological response against EBV and history of IM and cross-evaluates them with MS risk and genetic susceptibility in the Swedish population. Plasma IgG antibody levels against EBV nuclear antigen-1 (EBNA-1, truncated=aa[325-641], peptide=aa[385-420]) and viral capsid antigen p18 (VCAp18) were measured using bead-based multiplex serology for 8744 MS cases and 7229 population-matched controls. The MS risk association for high/low EBV antibody levels and history of IM was compared to relevant clinical measures along with sex, age at sampling, and associated HLA allele variants. Genome-wide and HLA allele association analyses were also performed to identify genetic risk factors for EBV antibody response and IM history. Higher antibody levels against VCAp18 (OR=1.74, 95% CI=1.60-1.88) and EBNA-1, particularly the peptide (OR=3.13, 95% CI=2.93-3.35), were associated with an increased risk for MS. The risk increased with higher anti-EBNA-1 IgG levels up to twelve times the reference risk. We also identified several independent HLA haplotypes associated with EBV serology overlapping with known MS risk alleles (e.g., DRB1*15:01). Although there were several candidates, no variants outside the HLA region reached genome-wide significance. Cumulative HLA risk for anti-EBNA-1 IgG levels, particularly the peptide fragment, was strongly associated with MS. In contrast, the genetic risk for high anti-VCAp18 IgG levels was not as strongly associated with MS risk. IM history was not associated with class II HLA genes but negatively associated with A*02:01, which is protective against MS. Our findings emphasize that the risk association between anti-EBNA-1 IgG levels and MS may be partly due to overlapping HLA associations. Additionally, the increasing MS risk with increasing anti-EBNA-1 levels would be consistent with a pathogenic role of the EBNA-1 immune response, perhaps through molecular mimicry. Given that high anti-EBNA-1 antibodies may reflect a poorly controlled T-cell defense against the virus, our findings would be consistent with DRB1*15:01 being a poor class II antigen in the immune defense against EBV. Lastly, the difference in genetic control of IM supports the independent roles of EBNA-1 and IM in MS susceptibility.
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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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Artritis Reumatoide , Factor Reumatoide , Humanos , Inflamación , Autoanticuerpos , Péptidos Cíclicos , Inmunoglobulina G , Inmunoglobulina M , Inmunoglobulina ARESUMEN
BACKGROUND: While multiple sclerosis (MS) affects less than 1 % of the general population, immune mediated inflammatory diseases (IMIDs) collectively influence 5-10 % of the population. Understanding familial co-aggregation of MS and other IMIDs carries important clinical and public health implications that will enable early detection and personalized treatment. OBJECTIVE: To estimate the familial association between MS and other IMIDs and to quantify their shared genetic basis. DESIGN: Register-based multi-generational nested case-control familial co-aggregation study and genetic correlation study. SETTING: Sweden. PARTICIPANTS: 24,995 individuals with MS matched with 253,870 controls and 1,283,502 first-degree relatives (mothers, fathers, full siblings, and offspring) for familial co-aggregation analysis; population of European ancestry for genetic correlation analysis. MEASUREMENTS: Logistic regressions with adjustment for covariates were used to estimate the odds ratios (ORs) of developing MS in individuals with first-degree relatives diagnosed with IMIDs compared to those without such family history. Pairwise genome-wide genetic correlations were estimated with linkage-disequilibrium score regression. RESULTS: We observed an OR for familial co-aggregation of MS of 1.09 (95 % confidence interval (95%CI) = 1.07-1.11) in families with IMIDs history compared to families without. The association remained broadly consistent after stratification by sex concordance of relative pairs and by kinships. 18 IMID subtypes showed a familial association with MS, 7 of which including other acute widespread myelin destruction, encephalitis or myelitis or encephalomyelitis, inflammatory bowel disease, autoimmune thyroid diseases, systemic lupus erythematosus, other inflammatory system diseases, and sarcoidosis withstood multiple correction. Genetic correlations further revealed a shared genetic basis between 7 IMID subtypes with MS. CONCLUSION: We demonstrated a modest familial co-aggregation of MS with several IMIDs, and such association is likely due to shared genetic factors.
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OBJECTIVES: To discover autoantibodies to non-modified proteins associated with the presence/absence of anticitrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA). METHODS: The autoantibody repertoire of 80 ACPA negative and 80 ACPA positive RA subjects from the Swedish population-based Epidemiological Investigation of RA (EIRA) cohort was screened using a suspension bead array built on protein fragments earlier described as autoimmunity targets. Four autoantibodies positive in the initial screening were validated in another set of EIRA samples containing 317 ACPA-positive, 302 ACPA-negative and 372 age- and sex-matched controls. The relationship between the four autoantibodies and lung abnormalities on high-resolution computed tomography (HRTC) was examined in 93 early RA patients from LURA cohort. Association between the autoantibodies, smoking and MHC class II alleles was assessed by logistic regression analysis. RESULTS: : Anti-ANOS1 and anti-MURC IgG levels were associated with ACPA-positive status (OR = 3.02; 95% CI 1.87-4.89; and OR = 1.86; 95% CI 1.16-2.97, respectively) and increased in ACPA-positive patients compared with controls. Anti-ANOS1 IgG was associated with smoking habit (OR = 2.11; 95% CI 1.22-3.69) and anti-MURC IgG with the presence of the MHC class II "shared-epitope" genes (OR = 1.95; 95% CI 1.11-3.46). Anti-TSPYL4 IgG was associated with ACPA-negative (OR = 0.41; 95% CI 0.19-0.89). Anti-TSPYL4 IgG and anti-MAP2K6 IgG levels were increased in the ACPA-negative patients compared with controls. Presence of anti-MAP2K6 IgG and anti-TSPYL4 IgG correlated negatively with HRCT-defined lung abnormalities. CONCLUSIONS: These four autoantibodies may be useful in diagnostics and in predicting clinical phenotypes of RA.
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BACKGROUND: Large register-based studies have reported an association between head trauma and increased risk of multiple sclerosis (MS). We aimed to investigate possible interactions between head trauma and MS-associated HLA genes in relation to MS risk. METHODS: We used a Swedish population-based case-control study (2807 incident cases, 5950 matched controls with HLA genotypes available for 2057 cases, 2887 controls). Subjects with and without a history of self-reported head trauma were compared regarding MS risk, by calculating ORs with 95% CIs using logistic regression models. Additive interaction between head trauma, HLA-DRB1*1501 and absence of HLA-A*0201, was assessed by calculating the attributable proportion (AP) due to interaction. RESULTS: A history of head trauma was associated with a 30% increased risk of subsequently developing MS (OR 1.34, 95% CI 1.17 to 1.53), with a trend showing increased risk of MS with increasing number of head impacts (p=0.03). We observed synergistic effects between recent head trauma and HLA-DRB1*15:01 as well as absence of HLA*02:01 in relation to MS risk (each AP 0.40, 95% CI 0.1 to 0.7). Recent head trauma in individuals with both genetic risk factors rendered an 18-fold increased risk of MS, compared with those with neither the genetic risk factors nor a history of head trauma (OR 17.7, 95% CI 7.13 to 44.1). CONCLUSIONS: Our findings align with previous observations of a dose-dependent association between head trauma and increased risk of MS and add a novel aspect of this association by revealing synergistic effects between recent head trauma and MS-associated HLA genes.
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Traumatismos Craneocerebrales , Predisposición Genética a la Enfermedad , Cadenas HLA-DRB1 , Esclerosis Múltiple , Humanos , Esclerosis Múltiple/genética , Esclerosis Múltiple/epidemiología , Femenino , Masculino , Estudios de Casos y Controles , Cadenas HLA-DRB1/genética , Predisposición Genética a la Enfermedad/genética , Traumatismos Craneocerebrales/epidemiología , Adulto , Suecia/epidemiología , Persona de Mediana Edad , Genotipo , Factores de Riesgo , Antígeno HLA-A2/genética , Adulto Joven , AncianoRESUMEN
BACKGROUND: Our study aims to investigate an intrinsic link underlying sex hormone-binding globulin (SHBG) and rheumatoid arthritis (RA), which remains inconclusive in observational settings. METHODS: Summary statistics were collected from the largest GWAS(s) on SHBG adjusted for BMI (SHBGadjBMI; Noverall = 368,929; Nmen = 180,094; Nwomen = 188,908), crude SHBG (Noverall = 370,125; Nmen = 180,726; Nwomen = 189,473), and RA (Ncase = 22,350; Ncontrol = 74,823). A genome-wide cross-trait design was performed to quantify global and local genetic correlation, identify pleiotropic loci, and infer a causal relationship. RESULTS: Among the overall population, a significant global genetic correlation was observed for SHBGadjBMI and RA ([Formula: see text] = 0.11, P = 1.0 × 10-4) which was further supported by local signal (1q25.2). A total of 18 independent pleiotropic SNPs were identified, of which three were highly likely causal variants and four were found to have effects on both traits through gene expression mediation. A putative causal association of SHBGadjBMI on RA was demonstrated (OR = 1.20, 95% CI = 1.01-1.43) without evidence of reverse causality (OR = 0.999, 95% CI = 0.997-1.000). Sex-specific analyses revealed distinct shared genetic regions (men: 1q32.1-q32.2 and 5p13.1; women: 1q25.2 and 22q11.21-q11.22) and diverse pleiotropic SNPs (16 in men and 18 in women, nearly half were sex-specific) underlying SHBGadjBMI and RA, demonstrating biological disparities between sexes. Replacing SHBGadjBMI with crude SHBG, a largely similar yet less significant pattern of results was observed. CONCLUSION: Our cross-trait analysis suggests an intrinsic, as well as a sex-specific, link underlying SHBG and RA, providing novel insights into disease etiology.
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Artritis Reumatoide , Globulina de Unión a Hormona Sexual , Masculino , Femenino , Humanos , Globulina de Unión a Hormona Sexual/genética , Genómica , Artritis Reumatoide/genética , Fenotipo , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
BACKGROUND AND PURPOSE: Higher latitude has been associated with increased occurrence of multiple sclerosis (MS) and with more severe disease. The aim was to study the impact of sun exposure habits on MS disease progression and health-related quality of life. METHODS: Patients from a population-based case-control study were categorized based on sun exposure habits at diagnosis and were followed up to 15 years post-diagnosis through the Swedish MS registry (n = 3314) with regard to changes in Expanded Disability Status Scale (EDSS). Linear mixed models were used to analyse long-term changes, while Cox regression models, with 95% confidence intervals, were used to investigate outcomes, including 24-week confirmed diasability worsening, EDSS3, EDSS4, and physical worsening as measured by the physical component of the Multiple Sclerosis Impact Scale 29. RESULTS: Compared to average sun exposure (median value), low exposure to sunlight was associated with faster EDSS progression, increased risk of confirmed disability worsening (hazard ratio [HR] 1.48, 95% CI 1.21-1.81), increased risk of reaching EDSS 3 (HR 1.35, 95% CI 1.02-1.79), EDSS 4 (HR 1.47, 95% CI 1.01-2.20) and self-reported physical worsening (HR 1.27, 95% CI 1.00-1.62). Significant trends revealed a lower risk of unfavourable outcomes with increasing sun exposure. CONCLUSIONS: Very low levels of sun exposure are associated with worse disease progression and health-related quality of life in patients with MS.
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Progresión de la Enfermedad , Esclerosis Múltiple , Calidad de Vida , Sistema de Registros , Luz Solar , Humanos , Masculino , Femenino , Adulto , Esclerosis Múltiple/epidemiología , Persona de Mediana Edad , Estudios de Casos y Controles , Suecia/epidemiología , Hábitos , Evaluación de la DiscapacidadRESUMEN
BACKGROUND: Multiple sclerosis (MS) is a demyelinating disease affecting millions of people worldwide. Hereditary susceptibility and environmental factors contribute to disease risk. Infection with Epstein-Barr virus (EBV) and human herpesvirus 6A (HHV-6A) have previously been associated with MS risk. Other neurotropic viruses, such as rubella virus (RV), are possible candidates in MS aetiopathogenesis, but previous results are limited and conflicting. METHODS: In this nested case-control study of biobank samples in a Swedish cohort, we analysed the serological response towards RV before the clinical onset of MS with a bead-based multiplex assay in subjects vaccinated and unvaccinated towards RV. The association between RV seropositivity and MS risk was analysed with conditional logistic regression. RESULTS: Seropositivity towards RV was associated with an increased risk of MS for unvaccinated subjects, even when adjusting for plausible confounders including EBV, HHV-6A, cytomegalovirus and vitamin D (adjusted odds ratio [AOR] = 4.0, 95% confidence interval [CI] 1.8-8.8). Cases also had stronger antibody reactivity towards rubella than controls, which was not seen for other neurotropic viruses such as herpes simplex or varicella zoster. Furthermore, we observed an association between RV seropositivity and MS in vaccinated subjects. However, this association was not significant when adjusting for the aforementioned confounders (AOR = 1.7, 95% CI 1.0-2.9). CONCLUSIONS: To our knowledge, these are the first reported associations between early RV seropositivity and later MS development. This suggests a broadening of the virus hypothesis in MS aetiology, where molecular mimicry between rubella epitopes and human central nervous system molecules could be an attractive possible mechanism.
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AIMS/HYPOTHESES: Smoking and use of smokeless tobacco (snus) are associated with an increased risk of type 2 diabetes. We investigated whether smoking and snus use increase the risk of latent autoimmune diabetes in adults (LADA) and elucidated potential interaction with HLA high-risk genotypes. METHODS: Analyses were based on Swedish case-control data (collected 2010-2019) with incident cases of LADA (n=593) and type 2 diabetes (n=2038), and 3036 controls, and Norwegian prospective data (collected 1984-2019) with incident cases of LADA (n=245) and type 2 diabetes (n=3726) during 1,696,503 person-years of follow-up. Pooled RRs with 95% CIs were estimated for smoking, and ORs for snus use (case-control data only). The interaction was assessed by attributable proportion (AP) due to interaction. A two-sample Mendelian randomisation (MR) study on smoking and LADA/type 2 diabetes was conducted based on summary statistics from genome-wide association studies. RESULTS: Smoking (RRpooled 1.30 [95% CI 1.06, 1.59] for current vs never) and snus use (OR 1.97 [95% CI 1.20, 3.24] for ≥15 box-years vs never use) were associated with an increased risk of LADA. Corresponding estimates for type 2 diabetes were 1.38 (95% CI 1.28, 1.49) and 1.92 (95% CI 1.27, 2.90), respectively. There was interaction between smoking and HLA high-risk genotypes (AP 0.27 [95% CI 0.01, 0.53]) in relation to LADA. The positive association between smoking and LADA/type 2 diabetes was confirmed by the MR study. CONCLUSIONS/INTERPRETATION: Our findings suggest that tobacco use increases the risk of LADA and that smoking acts synergistically with genetic susceptibility in the promotion of LADA. DATA AVAILABILITY: Analysis codes are shared through GitHub ( https://github.com/jeseds/Smoking-use-of-smokeless-tobacco-HLA-genotypes-and-incidence-of-LADA ).
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Diabetes Mellitus Tipo 2 , Diabetes Autoinmune Latente del Adulto , Tabaco sin Humo , Humanos , Tabaco sin Humo/efectos adversos , Diabetes Autoinmune Latente del Adulto/epidemiología , Diabetes Autoinmune Latente del Adulto/genética , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Estudio de Asociación del Genoma Completo , Estudios Prospectivos , Fumar/efectos adversos , Fumar/epidemiología , Fumar/genéticaRESUMEN
OBJECTIVES: To assess the effects of occupational inhalable exposures on rheumatoid arthritis (RA) development and their interactions with smoking and RA-risk genes, stratifying by presence of anticitrullinated protein antibodies (ACPA). METHODS: Data came from the Swedish Epidemiological Investigation of RA, consisting of 4033 incident RA cases and 6485 matched controls. Occupational histories were retrieved, combining with a Swedish national job-exposure matrix, to estimate exposure to 32 inhalable agents. Genetic data were used to define Genetic Risk Score (GRS) or carrying any copy of human leucocyte antigen class II shared epitope (HLA-SE) alleles. Associations were identified with unconditional logistical regression models. Attributable proportion due to interaction was estimated to evaluate presence of interaction. RESULTS: Exposure to any occupational inhalable agents was associated with increased risk for ACPA-positive RA (OR 1.25, 95% CI 1.12 to 1.38). The risk increased as number of exposed agents increased (Ptrend<0.001) or duration of exposure elongated (Ptrend<0.001). When jointly considering exposure to any occupational inhalable agents, smoking and high GRS, a markedly elevated risk for ACPA-positive RA was observed among the triple-exposed group compared with those not exposed to any (OR 18.22, 95% CI 11.77 to 28.19). Significant interactions were found between occupational inhalable agents and smoking/genetic factors (high GRS or HLA-SE) in ACPA-positive RA. CONCLUSIONS: Occupational inhalable agents could act as important environmental triggers in RA development and interact with smoking and RA-risk genes leading to excessive risk for ACPA-positive RA. Future studies are warranted to assess preventive strategies aimed at reducing occupational hazards and smoking, especially among those who are genetically vulnerable.
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Artritis Reumatoide , Predisposición Genética a la Enfermedad , Humanos , Cadenas HLA-DRB1/genética , Estudios de Casos y Controles , Factores de Riesgo , Artritis Reumatoide/epidemiología , Artritis Reumatoide/genética , Fumar/efectos adversos , Fumar/epidemiología , Antígenos HLA , Epítopos , AutoanticuerposRESUMEN
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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Artritis Reumatoide , Tromboembolia Venosa , Trombosis de la Vena , Humanos , Autoanticuerpos , Factor Reumatoide , Tromboembolia Venosa/epidemiología , Tromboembolia Venosa/etiología , Artritis Reumatoide/diagnóstico , Isotipos de Inmunoglobulinas , Fibrinógeno , Péptidos Cíclicos , Inmunoglobulina MRESUMEN
OBJECTIVES: We aimed to clarify the genetic overlaps underlying obesity-related traits, serum urate, and gout. METHODS: We conducted a comprehensive genome-wide cross-trait analysis to identify genetic correlation, pleiotropic loci, and causal relationships between obesity (the exposure variable), gout (the primary outcome) and serum urate (the secondary outcome). Summary statistics were collected from the hitherto largest genome-wide association studies conducted for BMI (N = 806 834), waist-to-hip ratio (WHR; N = 697 734), WHR adjusted for BMI (WHRadjBMI; N = 694 649), serum urate (N = 288 649), and gout (Ncases = 13 179 and Ncontrols = 750 634). RESULTS: Positive overall genetic correlations were observed for BMI (rg = 0.27, P = 6.62 × 10-7), WHR (rg = 0.22, P = 6.26 × 10-7) and WHRadjBMI (rg = 0.07, P = 6.08 × 10-3) with gout. Partitioning the whole genome into 1703 LD (linkage disequilibrium)-independent regions, a significant local signal at 4q22 was identified for BMI and gout. The global and local shared genetic basis was further strengthened by the multiple pleiotropic loci identified in the cross-phenotype association study, multiple shared gene-tissue pairs observed by Transcriptome-wide association studies, as well as causal relationships demonstrated by Mendelian randomization [BMI-gout: OR (odds ratio) = 1.66, 95% CI = 1.45, 1.88; WHR-gout: OR = 1.57, 95% CI = 1.37, 1.81]. Replacing the binary disease status of gout with its latent pathological measure, serum urate, a similar pattern of correlation, pleiotropy and causality was observed with even more pronounced magnitude and significance. CONCLUSION: Our comprehensive genome-wide cross-trait analysis demonstrates a shared genetic basis and pleiotropic loci, as well as a causal relationship between obesity, serum urate, and gout, highlighting an intrinsic link underlying these complex traits.
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Gota , Ácido Úrico , Humanos , Estudio de Asociación del Genoma Completo , Gota/epidemiología , Gota/genética , Obesidad/epidemiología , Obesidad/genética , Genética Humana , Polimorfismo de Nucleótido SimpleRESUMEN
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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BACKGROUND: Shift work, which often results in sleep deprivation and circadian desynchrony, has been associated with increased risk of multiple sclerosis (MS). We aimed at studying the impact of sleep duration, circadian disruption and sleep quality on MS risk. METHODS: We used a Swedish population-based case-control study (2075 cases, 3164 controls). Aspects of sleep were associated with MS risk by calculating OR with 95% CIs using logistic regression models. RESULTS: Compared with sleeping 7-9 hours/night during adolescence, short sleep (<7 hours/night) was associated with increased risk of developing MS (OR 1.4, 95% OR 1.1-1.7). Similarly, subjective low sleep quality during adolescence increased the risk of subsequently developing MS (OR 1.5, 95% CI 1.3 to 1.9), whereas phase shift did not significantly influence the risk. Our findings remained similar when those who worked shifts were excluded. CONCLUSIONS: Insufficient sleep and low sleep quality during adolescence seem to increase the risk of subsequently developing MS. Sufficient restorative sleep at young age, needed for adequate immune functioning, may be a preventive factor against MS.
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Esclerosis Múltiple , Privación de Sueño , Humanos , Adolescente , Privación de Sueño/complicaciones , Privación de Sueño/epidemiología , Esclerosis Múltiple/epidemiología , Estudios de Casos y Controles , Suecia/epidemiología , SueñoRESUMEN
We aimed to study the influence of smoking habits, exposure to passive smoking and snuff use on disease progression, cognitive performance and quality of life in patients with multiple sclerosis (MS). METHOD: Patients from two population-based case-control studies were categorised based on tobacco exposure at diagnosis and were followed up to 15 years post diagnosis through the Swedish MS registry (n=9089) regarding changes in Expanded Disability Status Scale (EDSS), Multiple Sclerosis Impact Scale 29 and Symbol Digit Modalities Test. We used linear mixed models to analyse long-term changes, and Cox regression models with 95% CI using 24-week confirmed disability worsening, reaching EDSS 3 and EDSS 4, respectively, physical and psychological worsening and cognitive disability worsening as end points. The influence of smoking cessation post diagnosis was also investigated. RESULTS: Compared with non-smokers, current smokers had a faster EDSS progression (ßcurrent smoking×time=0.03, 95% CI 0.02 to 0.04). A faster EDSS progression was also associated with passive smoking (ßcurrent passive smoking×time=0.04, 95% CI 0.03 to 0.06). Smoke exposure negatively impacted all secondary outcomes. Those who continued smoking had worse outcomes than those who stopped smoking post diagnosis. Snuff users had a more favourable EDSS progression, compared with never users. CONCLUSIONS: Our findings indicate that both smoking and passive smoking have a negative influence on MS and that smoking cessation post diagnosis may be an important secondary preventive measure. Snuff use was associated with slower disease progression, suggesting that nicotine replacement therapy could be an attractive way to increase the chance of quitting smoking among patients with MS.
Asunto(s)
Esclerosis Múltiple , Cese del Hábito de Fumar , Contaminación por Humo de Tabaco , Tabaco sin Humo , Humanos , Esclerosis Múltiple/complicaciones , Calidad de Vida , Progresión de la Enfermedad , Dispositivos para Dejar de Fumar Tabaco , Fumar/efectos adversos , Fumar/epidemiologíaRESUMEN
BACKGROUND: Spasticity is common among people with multiple sclerosis (MS), but there are few studies of spasticity treatment patterns. We aim to describe associations with spasticity treatment measured primarily by oral baclofen use. METHODS: This cohort study using Swedish registers included 1826 and 3519 people with incident and prevalent MS (pwIMS, pwPMS) respectively, followed from 2005 to 2014. Cox regression assessed factors associated with new baclofen prescriptions and its discontinuation. RESULTS: A total of 10% of pwIMS and 19% of pwPMS received baclofen, a drug prescribed specifically for spasticity in Sweden, of which many patients had relapsing-remitting course. Prescriptions occurred soon after MS diagnosis: pwIMS received baclofen typically within 6 months of diagnosis, and pwPMS within 3 years. Younger patients compared with older patients were three times more likely to receive baclofen with similar disability level measured using Expanded Disability Severity Scores (EDSS). Patients aged 18-44 years with EDSS 3.0-5.0 have an HR for baclofen use of 5.62 (95% CI 2.91 to 10.85) and EDSS 6+ have an HR of 15.41 (95% CI 7.07 to 33.58) compared with individuals with EDSS 0-2.5. In comparison, patients aged 45+ years with EDSS 3.0-5.0 have an HR of 2.05 (95% CI 1.10 to 3.82) and EDSS 6+ an HR of 4.26 (95% CI 1.96 to 9.17). Baclofen discontinuation was high: 49% (95% CI 0.42 to 0.57) of pwIMS discontinued within 150 days of dispensation, 90% discontinued within 2 years including patients with progressive course or higher EDSS. Associations among pwPMS and sensitivity analyses including additional treatments were similar. CONCLUSIONS: Younger patients with MS are more likely to receive baclofen compared with older patients with MS. High rates of baclofen discontinuation highlight the need for more tolerable and efficacious spasticity treatments and monitoring of spasticity among people with MS.
Asunto(s)
Esclerosis Múltiple Recurrente-Remitente , Esclerosis Múltiple , Humanos , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/tratamiento farmacológico , Baclofeno/uso terapéutico , Estudios de Cohortes , Suecia/epidemiología , Espasticidad Muscular/tratamiento farmacológico , Espasticidad Muscular/etiología , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológicoRESUMEN
OBJECTIVE: There is some evidence implicating diet in the development of inflammatory diseases. We aimed to study the influence of dietary habits on the risk of developing multiple sclerosis (MS). METHODS: We used a population-based case-control study recruiting incident cases of MS (1953 cases, 3557 controls). Subjects with different dietary habits 5 years prior to MS diagnosis were compared regarding MS risk by calculating odds ratios (OR) with 95% confidence intervals (CI) using logistic regression models. Adjustment was made for a large number of environmental and lifestyle habits, including ancestry, smoking, alcohol consumption, body mass index, physical activity, and sun exposure habits. RESULTS: Mediterranean diet was associated with lower risk of developing MS (adjusted OR = 0.54, 95% CI: 0.34-0.86, p = 0.009), compared with Western-style diet. There was no significant association between vegetarian/vegan diet and MS risk (adjusted OR = 0.96, 95% CI: 0.75-1.24, p = 0.976), nor between diet with low glycemic index and MS risk (adjusted OR = 0.93, 95% CI: 0.60-1.42, p = 0.518). CONCLUSIONS: Mediterranean diet may exert a protective influence regarding the risk of subsequently developing MS compared with Western-style diet.