Leflunomide discontinuation in rheumatoid arthritis and influence of associated disease-modifying anti-rheumatic drugs: a survival analysis

OBJECTIVES

The aims of this study were to describe the rate of leflunomide discontinuation in rheumatoid arthritis (RA) patients, in standard clinical practice, and to analyse which factors could influence this rate, paying particular attention to the concomitant treatment with other disease-modifying anti-rheumatic drugs (DMARDs).

METHOD

We selected RA patients, diagnosed according to the 1987 American College of Rheumatology (ACR) criteria, attending the rheumatology outpatient clinic of the San Carlos Clinical Hospital (Madrid, Spain), who had started treatment with leflunomide between 1 January 2006 and 1 January 2011. Clinical records were examined until withdrawal of the drug, loss of follow-up, or 1 October 2011. Kaplan-Meier curves were set to account for leflunomide withdrawal. Cox bivariate and multivariate regression models were conducted to examine risk factors for leflunomide discontinuation.

RESULTS

The incident rate (IR) for leflunomide discontinuation, regardless of the cause, was 27 per 100 patient-years [95% confidence interval (CI) 22-31]. We observed, in both the bivariate and multivariate regression analysis, that those aged > 75 years at the start of the leflunomide treatment and undergoing concurrent treatment with methotrexate (MTX) and/or hydroxychloroquine (HC) had a significantly higher risk of leflunomide discontinuation.

CONCLUSIONS

An older age at the start of the treatment with leflunomide, or concomitant treatment with MTX and/or HC, could be associated with a higher risk of leflunomide discontinuation, regardless of the cause. Therefore, when taking MTX or HC, patients receiving leflunomide should be closely monitored early to detect the occurrence of adverse reactions, and hence prevent their aggravation.

Influence of MHCIITA rs3087456 and rs4774 polymorphisms in the susceptibility to cardiovascular disease of patients with rheumatoid arthritis

OBJECTIVES

MHCIITA is a major regulator of MHC expression that has been reported to be involved in the susceptibility to rheumatoid arthritis (RA) and myocardial infarction. In this study we investigated the potential association of two MHCIITA gene polymorphisms with cardiovascular (CV) risk in patients with RA.

METHODS

1302 patients fulfilling the 1987 ACR classification criteria for RA were genotyped for the MHCIITA rs3087456 and rs4774 gene polymorphisms to determine the influence of MHCIITA variants in the development of CV events. The potential influence of these polymorphisms in the development of subclinical atherosclerosis was also analysed in a subgroup of patients with no history of CV events by the assessment of two surrogate markers of atherosclerosis; brachial and carotid ultrasonography to determine endothelial function and carotid artery intima-media thickness, respectively.

RESULTS

No statistically significant differences in the allele or genotype frequencies for each individual MHCIITA gene polymorphism between RA patients who experienced CV events, or not, were found. This was also the case when each polymorphism was assessed according to results obtained from surrogate markers of atherosclerosis. Also, in assessing the combined influence of both MHCIITA gene polymorphisms in the risk of CV disease after adjustment for gender, age at time of disease diagnosis, follow-up time, traditional CV risk factors, and shared epitope status, patients with CV events only showed a marginally decreased frequency of the MHCIITA rs3087456-rs4774 G-G allele combination (p=0.08; odds ratio: 0.63 [95% confidence interval: 0.37-1.05]).

CONCLUSIONS

Our data do not support an influence of MHCIITA rs3087456 and rs4774 polymorphisms in the increased risk of CV events of patients with RA.

Association of acid phosphatase locus 1*C allele with the risk of cardiovascular events in rheumatoid arthritis patients

Introduction

Acid phosphatase locus 1 (ACP1) encodes a low molecular weight phosphotyrosine phosphatase implicated in a number of different biological functions in the cell. The aim of this study was to determine the contribution of ACP1 polymorphisms to susceptibility to rheumatoid arthritis (RA), as well as the potential contribution of these polymorphisms to the increased risk of cardiovascular disease (CV) observed in RA patients.

Methods

A set of 1,603 Spanish RA patients and 1,877 healthy controls were included in the study. Information related to the presence/absence of CV events was obtained from 1,284 of these participants. All individuals were genotyped for four ACP1 single-nucleotide polymorphisms (SNPs), rs10167992, rs11553742, rs7576247, and rs3828329, using a predesigned TaqMan SNP genotyping assay. Classical ACP1 alleles (*A, *B and *C) were imputed with SNP data.

Results

No association between ACP1 gene polymorphisms and susceptibility to RA was observed. However, when RA patients were stratified according to the presence or absence of CV events, an association between rs11553742*T and CV events was found (P = 0.012, odds ratio (OR) = 2.62 (1.24 to 5.53)). Likewise, the ACP1*C allele showed evidence of association with CV events in patients with RA (P = 0.024, OR = 2.43).

Conclusions

Our data show that the ACP1*C allele influences the risk of CV events in patients with RA.

Lack of association of NAMPT rs9770242 and rs59744560 polymorphisms with disease susceptibility and cardiovascular risk in patients with rheumatoid arthritis

OBJECTIVES

Visfatin is an adipokine encoded by the NAMPT (PBEF1) gene. In this study we assessed the potential association of two NAMPT gene polymorphisms with disease susceptibility and cardiovascular (CV) risk in patients with rheumatoid arthritis (RA).

METHODS

A total of 1,395 patients fulfilling the 1987 ACR classification criteria for RA and 1,230 matched controls, were genotyped for the NAMPT rs9770242 and rs59744560 gene polymorphisms, located within the proximal promoter, using predesigned TaqMan single nucleotide polymorphism genotyping assay. Also, HLA-DRB1 genotyping was performed using molecular based methods. In a second step, 1,196 patients in whom full information was available were assessed to determine the influence of NAMPT rs9770242 and rs59744560 polymorphisms in the development of CV events. Also, the potential influence of these polymorphisms in the development of subclinical atherosclerosis was assessed in a subgroup of patients with no history of CV events by brachial artery reactivity to determine flow-mediated endothelium-dependent and endothelium-independent vasodilatation (n=125) and by B-mode ultrasonography to determine the carotid artery intima-media thickness (n=105).

RESULTS

No statistically significant differences in the allele or genotype frequencies for the NAMPT gene polymorphisms between RA patients and controls were found. A modest non significant lower frequency of the minor allele G of rs9770242 polymorphism was observed among patients with CV disease (20.62%) compared to those without CV disease (22.83%) (p=0.39). Also, a slight nonsignificant lower frequency of the minor allele T of rs59744560 polymorphism in patients with CV events (9.81%) compared with those RA patients who did not experience CV disease (13.07%) (p=0.11) was observed. Likewise, no significant association between the NAMPT polymorphisms with surrogate markers of subclinical atherosclerosis was found in patients with RA.

CONCLUSIONS

NAMPT rs9770242 and rs59744560 polymorphisms are not markers of disease susceptibility and CV disease in RA.

Lack of association between LEP rs2167270 (19 G>A) polymorphism and disease susceptibility and cardiovascular disease in patients with rheumatoid arthritis

OBJECTIVES

To assess the potential association between LEP rs2167270 (19 G>A) gene polymorphism and disease susceptibility and cardiovascular disease (CV) in patients with rheumatoid arthritis (RA).

METHODS

773 patients fulfilling the 1987 American College of Rheumatology classification criteria for RA, seen at the rheumatology outpatient clinics of Hospital Xeral-Calde, Lugo, and Hospital San Carlos, Madrid, Spain, and 957 matched controls, were studied. Patients were genotyped for the LEP rs2167270 (19G>A) polymorphism, located within the 5´UTR, using predesigned TaqMan single nucleotide polymorphism genotyping assay. Also, HLA-DRB1 genotyping was performed using molecular based methods. Subclinical atherosclerosis was assessed in a subgroup of patients with no history of CV events by brachial artery reactivity to determine flow-mediated endothelium-dependent and endothelium-independent vasodilatation (n=133) and by B-mode ultrasonography of the carotid artery intima-media thickness (n=113).

RESULTS

No statistically significant differences in the genotype or allele frequencies of the LEP rs2167270 gene polymorphism between patients with RA and controls were seen. Likewise, LEP rs2167270 polymorphism did not influence the development of CV events. Also, no significant differences in LEP rs2167270 genotype or allele distribution were seen when results of surrogate markers of subclinical atherosclerosis were assessed.

CONCLUSIONS

LEP rs2167270 polymorphism does not seem to be a genetic risk factor for disease susceptibility or clinically evident CV disease and subclinical atherosclerosis in patients with RA.