Risk Of RA Research Articles

Modifiable risk factors for RA: prevention, better than cure?

Objective. To perform a meta-synthesis of the evidence for modifiable lifestyle risk factors for inflammatory polyarthritis (IP) and RA.Methods. We performed a MEDLINE literature search. Case–control and cohort studies and systematic reviews published from 1948 through February 2011 and studying modifiable risk factors for RA were retrieved. The main outcome measure was diagnosis of RA according to the standard criteria.Results. Smoking contributes up to 25% of the population burden of RA. The risk is dose related, stronger in males and especially strong for anti-citrullinated peptide antibody positive (ACPA+) RA through an interaction with the shared epitope. After smoking cessation, there is, however, a latency of up to 20 years to return to baseline risk. Other associations are less definitive; however, prospective studies suggest that dietary antioxidants and breastfeeding may be protective and that high coffee consumption may increase RA risk. An inverse association with alcohol intake (especially in smokers) and with education/social class (especially seropositive RA) and an increased risk with obesity (seronegative RA) is also noted.Conclusion. There is a need for further large-scale prospective studies with a consistent definition of RA phenotype (undifferentiated IP through to ACPA+/RF+ disease). This will ultimately afford the opportunity to evaluate preventative population strategies for RA akin to the well-established programmes for cardiovascular disease and cancer, targeting common risk factors.

Genetic Risk Score Predicting Risk of Rheumatoid Arthritis Phenotypes and Age of Symptom Onset

BackgroundCumulative genetic profiles can help identify individuals at high-risk for developing RA. We examined the impact of 39 validated genetic risk alleles on the risk of RA phenotypes characterized by serologic and erosive status.Methods/Principal FindingsWe evaluated single nucleotide polymorphisms at 31 validated RA risk loci and 8 Human Leukocyte Antigen alleles among 542 Caucasian RA cases and 551 Caucasian controls from Nurses' Health Study and Nurses' Health Study II. We created a weighted genetic risk score (GRS) and evaluated it as 7 ordinal groups using logistic regression (adjusting for age and smoking) to assess the relationship between GRS group and odds of developing seronegative (RF− and CCP−), seropositive (RF+ or CCP+), erosive, and seropositive, erosive RA phenotypes. In separate case only analyses, we assessed the relationships between GRS and age of symptom onset.In 542 RA cases, 317 (58%) were seropositive, 163 (30%) had erosions and 105 (19%) were seropositive with erosions. Comparing the highest GRS risk group to the median group, we found an OR of 1.2 (95% CI = 0.8–2.1) for seronegative RA, 3.0 (95% CI = 1.9–4.7) for seropositive RA, 3.2 (95% CI = 1.8–5.6) for erosive RA, and 7.6 (95% CI = 3.6–16.3) for seropositive, erosive RA. No significant relationship was seen between GRS and age of onset.Conclusions/SignificanceResults suggest that seronegative and seropositive/erosive RA have different genetic architecture and support the importance of considering RA phenotypes in RA genetic studies.

Pulmonary dysfunction, smoking, socioeconomic status and the risk of developing rheumatoid arthritis

Environmental risk factors are of potential interest for both prevention and treatment of RA. The purpose of this study was to examine the effect of pulmonary function, smoking and socio-economic status on the future risk of RA. Between 1974 and 1992, 22 444 men and 10 902 women were included in the Malmö Preventive Medicine Program (MPMP). Pulmonary function was assessed by a standard screening spirometry. Chronic obstructive pulmonary disease (COPD) and restrictive pulmonary dysfunction were defined based on pulmonary function tests. Individuals who developed RA were identified by linking the MPMP database to national and local RA registers. The patients were classified according to the 1987 ACR criteria for RA. Four matched controls for every case were selected. We identified 290 cases of incident RA (151 men/139 women; mean age at diagnosis 60 years). The median time from inclusion to diagnosis was 12 years. Forced vital capacity and forced expiratory volume within 1 s values were similar in cases and controls, overall and also in separate analysis of those screened ≤8 years before diagnosis. There was no association between COPD or restrictive pulmonary dysfunction and subsequent development of RA. Current smoking was a strong predictor for RA [odds ratio (OR) 1.79; 95% CI 1.32, 2.42]. Blue-collar workers had an increased risk of RA (OR 1.54; 95% CI 1.12, 2.10), independent of smoking. Pulmonary dysfunction did not predict RA, but smoking and low socio-economic status were independent risk factors for RA. Other effects of smoking may be important for RA susceptibility.

RA and SLE Risk Factors Remain for Mothers and Babies

RA and SLE Risk Factors Remain for Mothers and Babies

Rheumatoid arthritis-associated polymorphisms are not protective against Alzheimer's disease

BackgroundRheumatoid arthritis (RA) and Alzheimer's disease (AD) are inversely associated. To test the hypothesis that genetic elements associated with increased RA risk are associated with decreased AD risk, we evaluated RA genetic risk factors recently identified in genome-wide association studies (GWAS) for their association with AD in a two-stage, case-control analysis.ResultsIn our Stage 1 analysis of ~800 AD and ~1,200 non-AD individuals, three of seventeen RA-associated SNPs were nominally associated with AD (p < 0.05) with one SNP, rs2837960, retaining significance after correction for multiple testing (p = 0.03). The rs2837960_G (minor) allele, which is associated with increased RA risk, was associated with increased AD risk. Analysis of these three SNPs in a Stage 2 population, consisting of ~1,100 AD and ~2,600 non-AD individuals, did not confirm their association with AD. Analysis of Stage 1 and 2 combined suggested that rs2837960 shows a trend for association with AD. When the Stage 2 population was age-matched for the Stage 1 population, rs2837960 exhibited a non-significant trend with AD. Combined analysis of Stage 1 and the age-matched Stage 2 subset showed a significant association of rs2837960 with AD (p = 0.002, OR 1.24) that retained significance following correction for age, sex and APOE (p = 0.02, OR = 1.20). Rs2837960 is near BACE2, which encodes an aspartic protease capable of processing the AD-associated amyloid precursor protein. Testing for an association between rs2837960 and the expression of BACE2 isoforms in human brain, we observed a trend between rs2837960 and the total expression of BACE2 and the expression of a BACE2 transcript lacking exon 7 (p = 0.07 and 0.10, respectively).ConclusionsRA-associated SNPs are generally not associated with AD. Moreover, rs2837960_G is associated with increased risk of both RA and, in individuals less than 80 years of age, with AD. Overall, these results contest the hypothesis that genetic variants associated with RA confer protection against AD. Further investigation of rs2837960 is necessary to elucidate the mechanism by which rs2837960 contributes to both AD and RA risk, likely via modulation of BACE2 expression.

TNF Inhibitors Reduce Cardiovascular Disease Risk in RA

TNF Inhibitors Reduce Cardiovascular Disease Risk in RA

A-SAA induces cytokine production and matrix metalloproteinase activity in adipose and RA synovial tissue

BackgroundRheumatoid arthritis (RA) is associated with a significant increase in cardiovascular (CV) mortality. Serum amyloid A (A-SAA), an acute phase protein with cytokine-like properties is increased 1000-fold during inflammation. Previously...

Renal Dysfunction May Predict Heart Disease Risk in RA

Renal Dysfunction May Predict Heart Disease Risk in RA

The influence of early life factors on the risk of developing rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease that develops as a result of the interaction between genetic and environmental risk factors. Although increasing evidence shows the importance of genes in determining the risk of RA, it is clear that environmental factors also have a vital role. Studies to date have tended to concentrate on environmental influences around the time of disease onset. However, a number of pieces of evidence, including the fact that autoantibodies, such as rheumatoid factor (RF), can develop several years before the onset of clinical disease, suggest that environmental factors may influence disease susceptibility during early life. Several recent studies lend weight to this possibility, with an increased risk of RA in the offspring of mothers who smoked during pregnancy and in those with higher birth weight. There has also been a suggestion that the risk of RA is reduced in breast-fed infants. We describe the evidence surrounding the effect of early life factors on the risk of developing RA and possible mechanisms by which they may act.

Using genetic and clinical data to understand response to disease-modifying anti-rheumatic drug therapy: data from the Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study

The objective of this review is to report on the progress of the Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS) Registry data collection and summarize previous research in understanding therapeutic response to DMARDs using clinical and genetic data. The BRASS Registry, established in 2003, is a large, single-centre, prospective and observational cohort of 1100 RA patients. Patients with either new-onset or established RA disease are recruited from the practices of rheumatologists. Annual visits collect information on demographics, 28-joint DAS-CRP3 (DAS-28-CRP3), medication use, comorbidities and functional status (Modified Health Assessment Questionnaire, Short Form Health Survey 12). Two published studies have utilized BRASS to examine genetic predictors of treatment response. In a cross-sectional study, examining the association between candidate single nucleotide polymorphisms (SNPs) and disease activity in a subset of 120 RA patients on MTX monotherapy, the minor allele of ATIC rs4673993 was associated with low disease activity (P=0.01, DAS-28-CRP3≤3.2). In an international collaboration, 55 BRASS patients receiving anti-TNF therapy were genotyped for 31 SNPs associated with the risk of RA. With our collaborators, we discovered an SNP at the protein tyrosine phosphatase, receptor type, C (PTPRC) gene locus that was associated with EULAR 'good response'. With accurate data collection and the capacity to run genome-wide association studies and SNP analyses, the BRASS Registry has the ability to determine the contribution of genetic variants to disease onset and to assess their usefulness as biomarkers for treatment response and drug toxicity.

Alcohol consumption is inversely associated with risk and severity of rheumatoid arthritis

To investigate the association between frequency of alcohol consumption and the risk and severity of RA. Frequency of alcohol consumption was recorded by patients and controls in a self-completed questionnaire. Odds ratios (ORs) for RA risk were calculated according to alcohol consumption, adjusted for age, gender and smoking status. Median values of all RA severity measures were then calculated according to the frequency of alcohol consumption, and the non-parametric trend test was used to assess association. A negative binomial regression model was used to adjust for potential confounding. Eight hundred and seventy-three patients with erosive RA, and 1004 healthy controls were included in the study. Risk of RA decreased according to frequency of alcohol consumption, such that non-drinkers had an OR for RA of 4.17 (3.01-5.77) compared with subjects consuming alcohol on >10 days per month (P for trend <0.0001). All measures of RA severity including CRP, 28-joint DAS, pain visual analogue scale, modified HAQ (mHAQ) and modified Larsen score were inversely associated with increasing frequency of alcohol consumption (P for trend, each <0.0001). After adjustment for potential confounding in a multivariate regression model, frequency of alcohol consumption remained significantly and inversely associated with X-ray damage and mHAQ. Although there are some limitations to this study, our data suggest that alcohol consumption has an inverse and dose-related association with both risk and severity of RA.

Common vaccines not shown to increase risk of RA

Common vaccines not shown to increase risk of RA

How microchimerism can impart HLA susceptibility in patients with rheumatoid arthritis

Rheumatoid arthritis, a chronic inflammatory joint disease, is strongly associated with HLA-DRB1*01 and *04 alleles that have in common similar 5-amino acid motifs in the third hypervariable region of DRB1 (QKRAA, QRRAA, RRRAA), the so called shared epitope (SE). Most patients with RA carry 1 or 2 doses of the SE, with particular genetic combinations at higher risk. In recent work we provided evidence that patients who lack HLA-DRB1*01 and/or *04 alleles can acquire RA susceptibility through fetal, maternal or iatrogenic microchimerism. We also discuss how Mc carrying HLA-DRB1*04 alleles is more likely to be present in the peripheral blood of RA patients compared to Mc carrying HLA-DRB1*01 alleles. We further analyze our results in light of the hierarchy for RA risk with different combinations of the SE. How Mc could contribute to RA susceptibility and whether it also contributes to the hierarchy of risk observed with particular combinations of SE-containing alleles is certainly the beginning of an intriguing story and may offer hope for future therapeutic and/or preventative interventions.

Anti-TNF-Alpha Tied to Lower Heart Risk in RA

Anti-TNF-Alpha Tied to Lower Heart Risk in RA

Genetic Variations in Genes Encoding RANK, RANKL, and OPG in Rheumatoid Arthritis: A Case-Control Study

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the joints, which may lead to structural damage of the cartilage and bone. The receptor activator of nuclear factor-kappaB (RANK) and the osteoprotegerin (OPG) cascade system have been reported to be essential in osteoclastogenesis. Genetic variations in the genes coding for RANK, RANK ligand (RANKL), and OPG are thought to play roles in the susceptibility to RA. In our case-control study, genomic DNA was obtained from 534 patients with RA who fulfilled the American College of Rheumatology 1987 criteria and 516 healthy control blood donors (HC). We studied 7 single-nucleotide polymorphisms (SNP) in the genes of RANK (2 SNP: rs1805034, rs35211496), OPG (2 SNP: rs3102735, rs2073618), and RANKL (3 SNP: rs9533156, rs2277438, rs1054016) using TaqMan assay-guided polymerase chain reaction. Genotype and allelic frequencies comparing RA patients with HC were analyzed by chi-square test for 2 x 3 and 2 x 2 tables, respectively. Genotype distributions of the SNP rs35211496 in the RANK gene as well as the SNP rs2277438 in the RANKL gene differed significantly between patients with RA and HC. The frequency of the minor allele of rs9533156 of RANKL was significantly higher in patients with RA than in HC (OR 0.84, 95% CI 0.71-0.99, p = 0.047). Multivariate analysis adjusted to sex and investigating SNP demonstrated a significantly elevated risk for RA associated with the major allele in the RANK SNP rs35211496 (p = 0.0231) and with the minor allele in the RANKL SNP rs2277438 (p = 0.0092). No significantly increased risk was detected in the other SNP. The minor allele of the RANK SNP rs35211496 may be protective against RA, while the minor alleles of the RANKL SNP rs2277438 may increase susceptibility to RA.

Rheumatoid arthritis is an independent risk factor for increased carotid intima-media thickness: impact of anti-inflammatory treatment

To evaluate the extent of subclinical atherosclerosis in patients with RA and low cardiovascular risk by measuring intima-media thickness (IMT) of the carotid arteries and to determine factors associated with increased IMT. IMT was measured by ultrasonography in 42 non-diabetic, normotensive, female RA patients and 32 matched healthy controls [age 45.3 (10.0) vs 45.2 (9.8) years] at common carotid arteries (CCAs), carotid bifurcation (BF) and internal carotid arteries (ICAs), bilaterally. Mean and maximal (max) IMTs were calculated from three measurements at each site. Clinical work-up included laboratory analyses, determination of the disease activity and evaluation of treatment. RA patients had increased IMT (mm) in comparison with controls [CCA(max): 0.764 (0.148) vs 0.703 (0.100); CCA(mean): 0.671 (0.119) vs 0.621 (0.085); BF(max): 1.055 (0.184) vs 0.941 (0.161); BF(mean): 0.889 (0.168) vs 0.804 (0.124); ICA(max): 0.683 (0.108) vs 0.613 (0.093); ICA(mean): 0.577 (0.101) vs 0.535 (0.076)]. Parameters associated with IMT in RA patients were (correlation at x/6 measurement sites): age (6/6), BMI (2/6), smoking (2/6), RF concentration (2/6), sedimentation rate (1/6) and duration of MTX + chloroquine therapy (4/6; inverse correlation). Multivariate regression analysis revealed that RA is an independent risk factor for increased IMT. Factors correlating with IMT in the controls were: age (6/6), BMI (3/6), total cholesterol (5/6), low-density lipoprotein cholesterol (3/6), total/high-density lipoprotein cholesterol (2/6), triglycerides (1/6) and glycaemia (4/6). Despite a favourable risk profile, our female RA patients had significantly enlarged carotid IMT than controls. RA itself was an independent risk factor for increased IMT. Impact of chronic inflammation on atherosclerosis was confirmed by negative correlation of IMT and duration of anti-inflammatory treatment.

Infection Risk in RA Linked With Comorbidities

Infection Risk in RA Linked With Comorbidities

Interpreting studies of interactions between RA risk factors

Interactions between HLA and PTPN22 genotypes and smoking have been implicated in overall susceptibility to rheumatoid arthritis as well as the incidence of particular disease phenotypes in case-control and case-only studies. As recent epidemiological evidence shows, deciphering these interactions demands consideration of the analytical approach used.

New classification of the shared epitope in rheumatoid arthritis: impact on the production of various anti-citrullinated protein antibodies

HLA-DR [shared epitope (SE)] alleles have recently been re-classified into S1, S2, S3P and S3D groups. S2 and S3P have been associated with increased risk for RA. We assessed the impact of S1, S2, S3P and S3D alleles on anti-citrullinated protein antibody (ACPA) production. Instead of comparing allele-carriers to non-carriers, we studied each allele group individually, using the X/X (non-SE) genotype as reference. Serum and genomic DNA samples of 91 RA patients and 78 healthy controls were obtained. Various ACPAs and IgM RF were determined by ELISA. HLA-DRB1 genotyping and subtyping was performed by PCR. HLA-DRB1 alleles were re-classified as described above. Correlations between SE and ACPAs were determined. Not only S2 and S3P, but, to a lesser extent, S1 and S3D alleles also predisposed to anti-cyclic citrullinated peptide (CCP) production (P < 0.0001, P = 0.004, P = 0.01 and P = 0.027, respectively), with the following hierarchy of association: S2+S3P > S1+S3D > X/X. Similar associations were observed for anti-citrullinated vimentin. Anti-citrullinated fibrinogen (CF) exerted a different association pattern with the strongest correlation with S1 alleles [odds ratio (OR) 16.00; P = 0.05]. In addition, HLA-DRB1*15 alleles may represent a special predisposing effect for anti-CF antibody production. Finally, in this study, RF production was associated only with the HLA-DRB1*0401 SE allele (P = 0.04). Our approach of comparing individual S allele carriers with X/X genotype patients allowed us to perform unequivocal analyses and demonstrate new associations. Thus, novel subgroups of RA could be identified with potential relevance for prognosis and therapy.

Mechanisms for Heart Disease Risk in RA Explored

Mechanisms for Heart Disease Risk in RA Explored