Steroids Decrease Prevalence of Positive Tuberculin Skin Test in Rheumatoid Arthritis: Implications on Anti-TNF Therapies

Shweta Agarwal,Siddharth Kumar Das,Girdhar G Agarwal,Ragini Srivastava

doi:10.1155/2014/430134

Abstract

Tuberculin skin test has been used as an indicator of latent tuberculosis in patients with Rheumatoid Arthritis (RA) before administration of biologicals. Effect of Disease modifying antirheumatic drugs (DMARDs) and steroids on the result of tuberculin skin test (TST) may have important implications in interpretation of results of this test. Objectives. To find the prevalence of positive TST in rheumatoid patients and the effect of standard treatment on the results of TST. Method. In this cross-sectional study two hundred and fifty patients of RA above 18 years of age, classified using 1987 ACR criteria for RA, were enrolled from rheumatology outdoor. Demographics, disease activity, disease duration, and therapy were recorded. All patients underwent TST. Results. Fifty-one (20.4%) patients were found to be tuberculin positive. Tuberculin positivity was not affected by MTX intake but it was significantly low in patients with recent steroid intake as compared to patients who had not taken steroids in last 3 months (3% versus 25%, P = 0.002). Conclusion. Prevalence of tuberculin positivity in patients with RA was found to be low. Results were not affected by methotrexate; however tuberculin skin test results in patients with recent use of steroids are likely to be negative.

Highlights

The association between rheumatoid arthritis (RA) and tuberculosis (TB) dates back to more than nine decades ago, when several clinicians in Germany and Forrestier in France related the chronic inflammation of tuberculosis to that of rheumatoid arthritis and used gold salts for the treatment of RA in the 1920s [1, 2] based on the fact that aurothiosulfate sodium was effective in the treatment of pulmonary tuberculosis [3]
Similar results have been reported from Spain and Sweden even before the anti-TNF era whereas studies from US reveal no difference in incidence of tuberculosis between the general population and those suffering from RA on standard therapy [6,7,8]
The patients were middle aged (47.2 ± 10.9 years), females (85.2%), nonsmokers (77.2%) with a mean duration of RA of 80.8 ± 63.7 months and moderate disease activity (43.6%) at study entry. 69.2% of the patients were found to be positive for rheumatoid factor

Summary

Introduction

The association between rheumatoid arthritis (RA) and tuberculosis (TB) dates back to more than nine decades ago, when several clinicians in Germany and Forrestier in France related the chronic inflammation of tuberculosis to that of rheumatoid arthritis and used gold salts for the treatment of RA in the 1920s [1, 2] based on the fact that aurothiosulfate sodium was effective in the treatment of pulmonary tuberculosis [3]. With the advent of steroids and DMARDs in the treatment of RA, researchers started debating the increased incidence of tuberculosis in RA due to immunosuppression. A large observational cohort study from Japan reported a 3.2-fold increased risk of tuberculosis in patients with RA treated with standard therapy [5]. Similar results have been reported from Spain and Sweden even before the anti-TNF era whereas studies from US reveal no difference in incidence of tuberculosis between the general population and those suffering from RA on standard therapy [6,7,8]. Various studies suggest 5- to 10-fold increased risk of reactivation of latent TB with the use of anti-TNF antibodies [9,10,11,12]

Methods

Results

Conclusion