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

Biomarkers associated with cardiovascular disease in patients with early rheumatoid arthritis

Objectives: Patients with rheumatoid arthritis (RA) have an increased mortality and morbidity due to cardiovascular disease (CVD). In this prospective 5-year follow up of patients with RA, we analysed several biomarkers, known to be associated with atherosclerosis and/or inflammation in the general population. The aim of this study was to find out whether the RA-disease per se affect these biomarkers and if those could be associated with the progression of atherosclerosis, as measured by intima media thickness (IMT) among patients with early RA. Methods: Patients from northern Sweden diagnosed with early RA, are consecutively recruited into an ongoing prospective study on CVD comorbidity. A subgroup of patients, aged ≤60 years (n = 71) was included for ultrasound measurements of IMT at inclusion (T0) and after 5 years (T5) together with age-sex-matched controls (n = 40). The patients were clinically assessed. Blood was analysed for lipids, ESR and CRP and several biomarkers known to be associated with atherosclerosis in the general population. Results: At T0, the patients with RA had significantly lower levels of MIF and significantly higher levels of interleukin (IL)-18 and MIC-1 compared with controls. At T5, the patients with RA had significantly higher levels of pentraxin3, MIC-1, TNF-R2, ICAM-1, VCAM-1 and endostatin compared with controls. At T0 the levels of MPO correlated with DAS28, sCD40L with CRP and IL-18 with systolic blood pressure and Reynolds risk score. Using PLSR on a CVD-panel analysed with multiplex immunoassay, the patients with RA could be correctly classified into those who had a worsening in their IMT over the five years or not. Here, MMP3 was identified as influential. Conclusions: This study indicates that the RA disease itself could affect several of the biomarkers in this study, and possibly also the processes involved in the development of atherosclerosis

Is Lipoprotein-Associated Phospholipase A2a Link between Inflammation and Subclinical Atherosclerosis inRheumatoid Arthritis?

Objective. Lipoprotein-associated phospholipase A2 (Lp-PLA2), a marker of vascular inflammation, is associated with cardiovascular disease. This prospective study of an inception cohort aimed to investigate whether the level of Lp-PLA2 is associated with subclinical atherosclerosis in patients with rheumatoid arthritis (RA). Methods. Patients from northern Sweden diagnosed with early RA were consecutively recruited into an ongoing prospective study. From these, all patients &lt;= 60 years (n = 71) were included for measurements of subclinical atherosclerosis at inclusion (T0) and five years later (T5). Forty age-and sex-matched controls were included. The patients were clinically assessed, SCORE, Reynolds Risk Score, and Larsen score were calculated, and blood samples were drawn from all individuals at T0 and T5. Results. There was no significant difference in the level of Lp-PLA2 between patients with RA and controls (p &gt; 0.05). In simple linear regression models among patients with RA, Lp-PLA2 at T0 was significantly associated with intima media thickness (IMT) at T0 and T5, flow mediated dilation (FMD) at T0 and T5, ever smoking, male sex, HDL-cholesterol (inversely), non-HDL-cholesterol, SCORE, Reynolds Risk Score, and Larsen score (p &lt; 0.05). Conclusion. In this cohort of patients with early RA, the concentration of Lp-PLA2 was associated with both subclinical atherosclerosis and disease severity

Is Lipoprotein-Associated Phospholipase A2 a Link between Inflammation and Subclinical Atherosclerosis in Rheumatoid Arthritis?

Objective. Lipoprotein-associated phospholipase A2 (Lp-PLA2), a marker of vascular inflammation, is associated with cardiovascular disease. This prospective study of an inception cohort aimed to investigate whether the level of Lp-PLA2 is associated with subclinical atherosclerosis in patients with rheumatoid arthritis (RA). Methods. Patients from northern Sweden diagnosed with early RA were consecutively recruited into an ongoing prospective study. From these, all patients ≤60 years ( = 71) were included for measurements of subclinical atherosclerosis at inclusion (T0) and five years later (T5). Forty age-and sex-matched controls were included. The patients were clinically assessed, SCORE, Reynolds Risk Score, and Larsen score were calculated, and blood samples were drawn from all individuals at T0 and T5. Results. There was no significant difference in the level of Lp-PLA2 between patients with RA and controls ( &gt; 0.05). In simple linear regression models among patients with RA, Lp-PLA2 at T0 was significantly associated with intima media thickness (IMT) at T0 and T5, flow mediated dilation (FMD) at T0 and T5, ever smoking, male sex, HDL-cholesterol (inversely), non-HDL-cholesterol, SCORE, Reynolds Risk Score, and Larsen score ( &lt; 0.05). Conclusion. In this cohort of patients with early RA, the concentration of Lp-PLA2 was associated with both subclinical atherosclerosis and disease severity

Age at onset determines severity and choice of treatment in early rheumatoid arthritis : a prospective study

INTRODUCTION: Disease activity, severity and co-morbidity contribute to increased mortality in patients with rheumatoid arthritis (RA). We evaluated the impact of age at disease onset on prognostic risk factors and treatment in early disease. METHODS: In this study, 950 RA patients were followed regularly from inclusion (&lt;12 months from symptom onset) for disease activity (erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tender/swollen joints, visual analogue scale (VAS) pain/global, disease activity score (DAS28)) and function (health assessment questionnaire (HAQ)). Disease severity, measured by radiographs of hands/feet (erosions, Larsen score), extra-articular disease, nodules and co-morbidities and treatment (disease-modifying anti-rheumatic drugs (DMARDs), corticosteroids, biologics, nonsteroidal anti-inflammatory drugs (NSAIDs)) were recorded at inclusion and after 5 years. Autoantibodies (rheumatoid factor (RF), anti-nuclear antibodies (ANA), antibodies against cyclic citrullinated peptides (ACPA)) and genetic markers (human leukocyte antibody (HLA)-shared epitope, protein tyrosine phosphatase nonreceptor type 22 (PTPN22)) were analyzed at inclusion. Data were stratified as young (YORA) and late (LORA) onset RA, defined as being below/above median age (58 years) at onset. RESULTS: LORA was associated with lower frequency of ACPA (P &lt;0.05) and carriage of PTPN22-T variant (P &lt;0.01), but with greater disease activity at inclusion measured as ESR (P &lt; 0.001), CRP (P &lt;0.01) and accumulated disease activity (area under the curve for DAS28) at 6 (P &lt;0.01), 12 (P &lt;0.01) and 24 months (P &lt;0.05), and a higher HAQ score (P &lt;0.01) compared with YORA. At baseline and 24 months, LORA was more often associated with erosions (P &lt;0.01 for both) and a higher Larsen score (P &lt;0.001 for both). LORA was more often treated with corticosteroids (P &lt;0.01), less often with methotrexate (P &lt;0.001) and biologics (P &lt;0.001). YORA was more often associated with early DMARD treatment (P &lt;0.001). Multiple regression analyses supported our findings regarding impact of age on chosen treatment. CONCLUSION: YORA patients were more frequently ACPA-positive. LORA was more often associated with erosions, higher Larsen scores, disease activity and HAQ at baseline. Nevertheless, YORA was treated earlier with DMARDs, whilst LORA was more often treated with corticosteroids and with less DMARDs in early disease. This could have implications for development of co-morbidities

Co-morbidity in patients with early rheumatoid arthritis - inflammation matters

Background: Patients with rheumatoid arthritis (RA) suffer from co-morbidities that contribute to a shortened lifespan. Inflammation is important for the development of cardiovascular disease, but little is known on its relationship with other co-morbidities. We investigated the role of inflammation for the development of new comorbidities in early RA. Methods: Since 1995, all patients with early RA in Northern Sweden are included in a prospective study on comorbidities, with a total of 950 patients being included. At the time for this study, 726 had been ill for &gt;= 5 years. Data on co-morbidities, clinical and laboratory disease activity and pharmacological therapy were collected from patient records and further validated using a questionnaire at RA onset (T0) and after 5 years (T5). Results: Of the patients, 53.2 % of the patients had one or more co-morbidity at onset, the commonest being: hypertension (27.3 %), obstructive pulmonary disease (13.9 %), diabetes (8.0 %), hypothyroidism (6.3 %) and malignancy (5.0 %). After 5 years, 41.0 % had developed at least one new co-morbidity, the most common being: hypertension (15.1 %), malignancy (7.6 %), stroke/transient ischemic accident (5.1 %), myocardial infarction (4.3 %) and osteoporosis (3.7 %). Age at disease onset, a raised erythrocyte sedimentation rate (ESR) at inclusion, previous treatment with glucocorticoids (GC; p &lt; 0.001 for all), extra-articular RA (Ex-RA; p &lt; 0.01), DAS28 (area under the curve) at 24 months (p &lt; 0.05), previous smoking at inclusion (p = 0.058) and male gender (p &lt; 0.01) were associated with a new co-morbidity overall at T5. Treatment with biologics (p &lt; 0.05) reduced the risk. In multiple logistic regression modelling, ESR (p = 0.036) at inclusion was associated with a new co-morbidity after 5 years, adjusted for age, sex, smoking and GC treatment. In a similar model, Ex-RA (p &lt; 0.05) was associated with a new co-morbidity at T5. In a third model, adjusted for age and sex, a new pulmonary co-morbidity was associated with a smoking history at inclusion (p &lt; 0.01), but not with ESR. Conclusion: There was substantial co-morbidity among early RA patients already at disease onset, with considerable new co-morbidity being added during the first five years. Measures of disease activity were associated with the occurrence of a new co-morbidity indicating that the inflammation is of importance in this context

Cardiovascular events in early rheumatoid arthritis (RA) are a result of inflammatory burden and traditional risk factors : a five year prospective study

Introduction Co-morbidity and mortality due to cardiovascular disease (CVD) are increased in patients with rheumatoid arthritis (RA). Most published studies in this field are retrospective or cross sectional. We investigated the presence of traditional and disease related risk factors for CVD at the onset of RA and during the first 5 years following diagnosis. We also evaluated their potential for predicting a new cardiovascular event (CVE) during the 5 year follow-up period and the modulatory effect of pharmacological treatment. Methods All patients from the four northern-most counties of Sweden with early RA are since December 1995 consecutively recruited at diagnsosis (T0) into a large survey on the progress of the disease. Information regarding cardiovascular co-morbidity and related predictors was collected from clinical records and supplemented with questionnaires. By April 2008, 700 patients had been included of whom 442 patients had reached the 5-year follow-up (T5). Result Among the 442 patients who reached T5 during the follow-up period, treatment for hypertension increased from 24.5 to 37.4% ( p&lt;0.001)), diagnosis of diabetes mellitus (DM) from 7.1 to 9.5%(p&lt;0.01) whilst smoking decreased from 29.8 to 22.4 % ( p&lt;0.001) and the BMI from 26.3 to 25.8( p&lt;0.05) , respectively. By T5, 48 patients had suffered a new CVE of which 12 were fatal. A total of 23 patients died during the follow-up period. Age at disease onset, male sex, a previous CVE, DM, treatment for hypertension, triglyceride level, cumulative disease activity (AUC DAS28), extra-articular disease, corticosteroid use, shorter duration of treatment with DMARDs and use of COX-2 inhibitors increased the hazard rate for a new CVE. A raised ESR at inclusion and AUC DAS28 at 6 months increased the hazard rate of CVE independently whilst DMARD treatment was protective in multiple Cox extended models adjusted for sex and CV risk factors. The risk of a CVE due to inflammation was potentiated by traditional CV risk factors. Conclusion The occurrence of new CV events in very early RA was explained by traditional CV risk factors and was potentiated by high disease activity. Treatment with DMARDs decreased the risk. The results may have implications for cardio-protective strategies in RA

Polymorphisms in the Tyrosine Kinase 2 and Interferon Regulatory Factor 5 Genes Are Associated with Systemic Lupus Erythematosus

Systemic 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