Frequency of positivity of the tuberculin intradermorreaction test in a cohort of patients with rheumatoid arthritis

Introduction: Rheumatoid arthritis is an autoimmune, chronic, and deforming condition associated with disability. Patients are immunosuppressed and at high risk of developing tuberculosis. The tuberculin skin test is used to screen candidates for biological therapy. Objective: To evaluate the frequency of positivity of the tuberculin skin test in a cohort of Colombian patients with rheumatoid arthritis. Materials and methods: We conducted a descriptive cross-sectional study including patients with rheumatoid arthritis receiving the tuberculin skin test prior to the start or at the time of the change of biological therapy. The patients’ condition was moderate or severe and they were candidates for initiation or change of biological therapy. We defined the value of ≥6 mm as the cut-off point for a positive tuberculin skin test and performed a descriptive analysis for each of the variables considered. Results: In total, 261 patients with rheumatoid arthritis were included, 92 % of whom were women; the average age was 55 years (SD=13.92) and the time from diagnosis, 12.3 years (SD=8.54). The frequency of positive tuberculin skin tests was 15.71% (n=41). Of the 41 positive patients, nine had previously had the test (1 to 6 years before), all of them with negative results; 18 of these were receiving glucocorticoids (43.9%) and all of them (100%) were being treated with methotrexate. Conclusions: The frequency of positivity of the tuberculin skin test in these Colombian patients diagnosed with rheumatoid arthritis was around 16%. We reco0mmend optimizing strategies aimed at an optimal detection of this condition and the timely initiation of treatment to reduce the risk of tuberculosis reactivation.