Mannan Binding Lectin (MBL) genotypes coding for high MBL serum levels are associated with rheumatoid factor negative rheumatoid arthritis in never smokers

To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.INTRODUCTION: Previous studies have provided inconsistent results on whether variants in the MBL2 gene, coding for the complement-activating mannan-binding lectin (MBL) protein, associate with rheumatoid arthritis (RA). We re-evaluated this in context of the main environmental and genetic risk factors (smoking, HLA-DRB1 'shared epitope' (SE), PTPN22*620W), which predispose to rheumatoid factor (RF) and/or anti-citrullinated-protein antibody (ACPA)-positive RA. METHODS: In this population-based EIRA study, rheumatoid factor (RF), ACPA, smoking, SE and PTPN22*620W status was determined in incident RA cases and matched controls. MBL-high (n = 1330) and MBL-low (n = 1257) genotypes predicting MBL levels were constructed from four promoter and exon-1 polymorphisms in the MBL2 gene. Odds ratios with 95% confidence interval (OR, 95% CI) were calculated by logistic regression. In extended families (n = 316), previously reported data were re-analyzed, considering RF and smoking. RESULTS: MBL-high genotypes tended to be associated with RF-negative (OR = 1.20, 95% CI 0.96-1.51) but not RF-positive (OR = 1.00, 95% CI 0.83-1.20) RA. Results divided by ACPA status did not differ. When stratified for smoking, MBL-high genotype was strongly associated with RF-negative RA in never smokers (OR = 1.82, 95% CI 1.24-2.69) but not in ever smokers (OR = 0.96, 95% CI 0.73-1.30). In never smokers, the association was observed in both the RF-negative/ACPA-negative (OR = 1.67, 95% CI 1.10-2.55) and RF-negative/ACPA-positive subgroups (OR = 3.07, 95% CI 1.37-6.89), and remained on an SE/PTPN22*620W negative background. In the extended families, the reported association between high MBL and RA was in fact confined to never smokers. CONCLUSIONS: High MBL may predispose to RF-negative RA but only in individuals who have never smoked. This illustrates the importance of phenotypic subgrouping in genetic studies.Stockholm county Swedish Medical Research Council Stockholm County Council Flight Attendant Medical Research Institute Swedish Council for Working Life and Social Research King Gustaf V's 80-year foundation Swedish Rheumatism Association Swedish COMBINE project E

Polymorphisms in the tyrosine kinase 2 and interferon regulatory factor 5 genes are associated with systemic lupus erythematosus

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldSystemic lupus erythematosus (SLE) is a complex systemic autoimmune disease caused by both genetic and environmental factors. Genome scans in families with SLE point to multiple potential chromosomal regions that harbor SLE susceptibility genes, and association studies in different populations have suggested several susceptibility alleles for SLE. Increased production of type I interferon (IFN) and expression of IFN-inducible genes is commonly observed in SLE and may be pivotal in the molecular pathogenesis of the disease. We analyzed 44 single-nucleotide polymorphisms (SNPs) in 13 genes from the type I IFN pathway in 679 Swedish, Finnish, and Icelandic patients with SLE, in 798 unaffected family members, and in 438 unrelated control individuals for joint linkage and association with SLE. In two of the genes--the tyrosine kinase 2 (TYK2) and IFN regulatory factor 5 (IRF5) genes--we identified SNPs that displayed strong signals in joint analysis of linkage and association (unadjusted P<10(-7)) with SLE. TYK2 binds to the type I IFN receptor complex and IRF5 is a regulator of type I IFN gene expression. Thus, our results support a disease mechanism in SLE that involves key components of the type I IFN system

Osteopontin and disease activity in patients with recent-onset systemic lupus erythematosus:results from the SLICC Inception Cohort

Objective. In cross-sectional studies, elevated osteopontin (OPN) levels have been proposed to reflect, and/or precede, progressive organ damage and disease severity in systemic lupus erythematosus (SLE). We aimed, in a cohort of patients with recent-onset SLE, to determine whether raised serum OPN levels precede damage and/or are associated with disease activity or certain disease phenotypes. Methods. We included 344 patients from the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort who had 5 years of followup data available. All patients fulfilled the 1997 American College of Rheumatology (ACR) criteria. Baseline sera from patients and from age- and sex-matched population-based controls were analyzed for OPN using ELISA. Disease activity and damage were assessed at each annual followup visit using the SLE Disease Activity Index 2000 (SLEDAI-2K) and the SLICC/ACR damage index (SDI), respectively. Results. Compared to controls, baseline OPN was raised 4-fold in SLE cases (p < 0.0001). After relevant adjustments in a binary logistic regression model, OPN levels failed to significantly predict global damage accrual defined as SDI ≥ 1 at 5 years. However, baseline OPN correlated with SLEDAI-2K at enrollment into the cohort (r = 0.27, p < 0.0001), and patients with high disease activity (SLEDAI-2K ≥ 5) had raised serum OPN (p < 0.0001). In addition, higher OPN levels were found in patients with persistent disease activity (p = 0.0006), in cases with renal involvement (p < 0.0001) and impaired estimated glomerular filtration rate (p = 0.01). Conclusion. The performance of OPN to predict development of organ damage was not impressive. However, OPN associated significantly with lupus nephritis and with raised disease activity at enrollment, as well as over time

Glucocorticoid use and factors associated with variability in this use in the Systemic Lupus International Collaborating Clinics Inception Cohort

To describe glucocorticoid (GC) use in the SLICC inception cohort and to explore factors associated with GC use. In particular we aimed to assess temporal trends in GC use and to what extent physician-related factors may influence use. Patients were recruited within 15 months of diagnosis of SLE from 33 centres between 1999 and 2011 and continue to be reviewed annually. Descriptive statistics were used to detail oral and parenteral GC use. Cross sectional and longitudinal analyses were performed to explore factors associated with GC use at enrolment and over time. We studied 1700 patients with a mean (s.d.) follow-up duration of 7.26 (3.82) years. Over the entire study period, 1365 (81.3%) patients received oral GCs and 447 (26.3%) received parenteral GCs at some point. GC use was strongly associated with treatment centre, age, race/ethnicity, sex, disease duration and disease activity. There was no change in the proportion of patients on GCs or the average doses of GC used over time according to year of diagnosis. GCs remain a cornerstone in SLE management and there have been no significant changes in their use over the past 10-15 years. While patient and disease factors contribute to the variation in GC use, between-centre differences suggest that physician-related factors also contribute. Evidence-based treatment algorithms are needed to inform a more standardized approach to GC use in SL

Impact of early disease factors on metabolic syndrome in systemic lupus erythematosus: data from an international inception cohort.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The metabolic syndrome (MetS) may contribute to the increased cardiovascular risk in systemic lupus erythematosus (SLE). We examined the association between MetS and disease activity, disease phenotype and corticosteroid exposure over time in patients with SLE.Recently diagnosed (1, higher disease activity, increasing age and Hispanic or Black African race/ethnicity were independently associated with MetS over the first 2 years of follow-up in the cohort.MetS is a persistent phenotype in a significant proportion of patients with SLE. Renal lupus, active inflammatory disease and damage are SLE-related factors that drive MetS development while antimalarial agents appear to be protective from early in the disease course.Canadian Institutes of Health Research 93695 86526 Arthritis Research UK (Arthritis Research UK Epidemiology Unit Core Support Programme Grant) National Institute for Health Research (NIHR) Biomedical Research Unit Funding Scheme NIHR Manchester Biomedical Research Centre Arthritis Research UK Manchester Academic Health Science Centre NIHR Biomedical Research Unit Funding Scheme NIHR Manchester Wellcome Trust Clinical Research Facility Arthritis Research Clinical Research Fellowship 18845 Ministry for Health and Welfare, Republic of Korea A120404 Lupus UK NIHR/Wellcome Trust Clinical Research Facility at University Hospital Birmingham NHS Foundation Trust and City Hospital Sandwell and West Birmingham Hospitals NHS Trust, UK NIH UL1 RR025741 P60AR 30692 K24 AR 002138 RR00046 Hopkins Lupus Cohort NIH RD-1 43727 Department of Education, Universities and Research, Basque Government Singer Family Fund for Lupus Research tier 1 Canada Research Chair on Systemic Autoimmune Rheumatic Diseases, Universite Lava

Fourteen sequence variants that associate with multiple sclerosis discovered by meta-analysis informed by genetic correlations

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesA meta-analysis of publicly available summary statistics on multiple sclerosis combined with three Nordic multiple sclerosis cohorts (21,079 cases, 371,198 controls) revealed seven sequence variants associating with multiple sclerosis, not reported previously. Using polygenic risk scores based on public summary statistics of variants outside the major histocompatibility complex region we quantified genetic overlap between common autoimmune diseases in Icelanders and identified disease clusters characterized by autoantibody presence/absence. As multiple sclerosis-polygenic risk scores captures the risk of primary biliary cirrhosis and vice versa (P = 1.6 x 10(-7), 4.3 x 10(-9)) we used primary biliary cirrhosis as a proxy-phenotype for multiple sclerosis, the idea being that variants conferring risk of primary biliary cirrhosis have a prior probability of conferring risk of multiple sclerosis. We tested 255 variants forming the primary biliary cirrhosis-polygenic risk score and found seven multiple sclerosis-associating variants not correlated with any previously established multiple sclerosis variants. Most of the variants discovered are close to or within immune-related genes. One is a low-frequency missense variant in TYK2, another is a missense variant in MTHFR that reduces the function of the encoded enzyme affecting methionine metabolism, reported to be dysregulated in multiple sclerosis brain.Swedish Research Council Knut and Alice Wallenberg Foundation AFA Foundation Swedish Brain Foundatio

25-Hydroxyvitamin D and Cardiovascular Disease in Patients With Systemic Lupus Erythematosus: Data From a Large International Inception Cohort: Vitamin D 25(OH)D and CVD in SLE Patients

An association between 25-hydroxyvitamin D (25[OH]D; vitamin D) deficiency and increased cardiovascular (CV) risk factors and CV disease (CVD) has been shown in general population studies. Vitamin D deficiency has been noted in systemic lupus erythematosus (SLE), and CVD is a major cause of morbidity and mortality in SLE. The objectives of this study were to estimate the associations of 25(OH)D levels with CV risk factors and to determine whether low baseline 25(OH)D levels predict future CV events in patients participating in an international inception cohort

Factors associated with damage accrual in patients with systemic lupus erythematosus: results from the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort.

BACKGROUND AND AIMS: We studied damage accrual and factors determining development and progression of damage in an international cohort of systemic lupus erythematosus (SLE) patients. METHODS: The Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort recruited patients within 15 months of developing four or more 1997 American College of Rheumatology (ACR) criteria for SLE; the SLICC/ACR damage index (SDI) was measured annually. We assessed relative rates of transition using maximum likelihood estimation in a multistate model. The Kaplan-Meier method estimated the probabilities for time to first increase in SDI score and Cox regression analysis was used to assess mortality. RESULTS: We recruited 1722 patients; mean (SD) age 35.0 (13.4) years at cohort entry. Patients with damage at enrolment were more likely to have further worsening of SDI (SDI 0 vs ≥1; p<0.001). Age, USA African race/ethnicity, SLEDAI-2K score, steroid use and hypertension were associated with transition from no damage to damage, and increase(s) in pre-existing damage. Male gender (relative transition rates (95% CI) 1.48 (1.06 to 2.08)) and USA Caucasian race/ethnicity (1.63 (1.08 to 2.47)) were associated with SDI 0 to ≥1 transitions; Asian race/ethnicity patients had lower rates of new damage (0.60 (0.39 to 0.93)). Antimalarial use was associated with lower rates of increases in pre-existing damage (0.63 (0.44 to 0.89)). Damage was associated with future mortality (HR (95% CI) 1.46 (1.18 to 1.81) per SDI point). CONCLUSIONS: Damage in SLE predicts future damage accrual and mortality. We identified several potentially modifiable risk factors for damage accrual; an integrated strategy to address these may improve long-term outcomes

C4A deficiency and elevated level of immune complexes: the mechanism behind increased susceptibility to systemic lupus erythematosus.

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldOBJECTIVE: Studies of an Icelandic cohort showed that susceptibility to systemic lupus erythematosus (SLE) in individuals with C4A deficiency was increased only in the presence of increased concentrations of immune complexes. We investigated the interaction of C4A deficiency with elevated concentrations of immune complexes in healthy individuals; i.e., how different levels of C4A affected the activation of C4 and C3 and subsequent binding of increased immune complex load to human red blood cells (RBC). METHODS: Forty-five healthy individuals having different levels of C4A were studied, 8 with homozygous C4AQ0, 12 with heterozygous C4A deficiency, and 25 with normal C4A. For comparison to the complement status present after prolonged disease activity, 5 patients with SLE homozygous for C4AQ0 were also studied. RESULTS: The results showed that intact immune complex-RBC binding is dependent on the levels of immune complex-bound C3 fragments, which correlate to the levels of IC-bound C4Ad (R = 0.677, p = 0.02), but not on levels of IC-bound total C4d (R = 0.451, p = 0.16). Immune complex binding to RBC was also evaluated in increasing immune complex load. C4A deficient sera had less ability to bind the increased immune complex load to RBC than sera with normal C4A. These results are consistent with the presence of increased amounts of poorly opsonized immune complexes in C4A deficiency, leading to increased precipitation in tissues and initiation of a self-perpetuating cycle. CONCLUSION: Susceptibility to SLE is increased in individuals with C4A deficiency as C3 opsonization of immune complexes becomes insufficient at elevated immune complex concentrations

Patients with Rheumatoid Arthritis Have Higher Levels of Mannan-Binding Lectin Than Their First-degree Relatives and Unrelated Controls.

To access publisher full text version of this article. Please click on the hyperlink in Additional LinkOBJECTIVE: Mannan-binding lectin (MBL) is present in serum and synovial fluid; its levels vary widely, and the variations are strongly associated with polymorphisms in the MBL2 gene. Studies have compared MBL in patients with rheumatoid arthritis (RA) and in unrelated controls, but the findings have been contradictory. In the first family-based study, we compared MBL levels in patients with RA to population controls and also to their nonaffected first-degree relatives, who may be regarded as optimal controls because of less genetic variation. METHODS: Serum levels of MBL and rheumatoid factor were analyzed in 210 patients with RA and 406 of their first-degree relatives from 74 extended families. Population controls for MBL levels were 330 randomly selected adult Icelanders. RESULTS: Patients with RA had higher MBL levels in serum (median 1553 microg/l) than their first-degree relatives (1073 microg/l; p = 0.003) and the unrelated controls (938 microg/l; p < 0.0001). No association was found between MBL and rheumatoid factor. CONCLUSION: Patients with RA had markedly higher MBL levels than their close relatives and controls, indicating that high MBL may predispose to RA. As MBL has been shown to bind potential arthritogenic agents including modified immunoglobulins, cellular debris, and microorganisms, our findings suggest that high MBL could trigger complement mediated inflammation within joints