The Latent Tuberculin Test after 1-year Therapy with Anti-TNF in Babylon, Iraq

Abstract

Background: Rheumatoid arthritis (RA) patients receiving receive anti-TNF agents are at increased risk of reactivation of latent tuberculosis infection (LTBI). The tuberculin skin test (TST) is widely used to screen LTBI and providing preventive treatment, in an effort to meet the WHO target of a 90% reduction in TB by 2035.
 Objectives: To determine the proportion of TST conversion among RA patients after 1 year of anti-TNF treatment and association of positive TST result with patients’ socio-demographic characteristics and medical history.
 Methods: This community-based cross-sectional study was conducted at the Department of Rheumatology of Marjan Teaching Hospital in Iraq, for a period of 1 year. Patients with RA/and spondyloarthropathy, and who received anti-TNF therapy for >1 year, underwent TST. Their demographic data and medical history were also obtained. All statistical analysis was performed using SPSS (Version 20) and, p < 0.05 was considered as a sign. Data from the baseline and 1 year follow-up was subjected to the Kolmogorov-Smirnov test to determine whether they were normally distributed. Chi-Square test used to test significance of TST among etanrecept and infliximab at the end of the study.
 Results: A total of 96 patients were enrolled, including 55 (57.3%) males and 41 (42.3%) females with an average age of 41.1, and mostly 68 (70.8%) from Babylon Governorate of Iraq. A total of 40 (41.7%) patients had rheumatoid arthritis alone, and the remaining 56 (58.3%) had a comorbidity of spondyloarthropathy. Majority of the patients 65 (67.7%) received the biological agent infliximab, while 31 (32.3%) patients received Etanercept for RA for a period of 1 year. There was a statistically significant decreasing in the median ESR and disease activity from the baseline to the end of the study (p-value <0.01). There was no significant difference in TST results based on gender or age. Both infliximab and etanercept were significantly associated with a decreasing in ESR and disease activity
 Conclusion: This study has shown that there was very low TST conversion among RA patients after 1 year of anti-TNF treatment and, age and gender were not associated with TST.