Screening for Latent Tuberculosis Infection at a Rheumatology and Medical Rehabilitation Center in Duhok City, Iraq

Abstract

Background: Patients with rheumatoid diseases are at increased risk of infection due to a combination of inherent energy or immunomodulating drugs used for its treatment. The study aimed to screen for latent tuberculosis infection (LTBI) among patients with rheumatologic diseases. Materials and Methods: In the present prospective cross-sectional study, a total of 149 patients diagnosed with different types of rheumatoid diseases were included. The rheumatic diseases were diagnosed based on the American College of Rheumatology criteria for rheumatoid arthritis (RA) or the European Spondyloarthropathy Study Group preliminary criteria for the classification of spondyloarthropathy. The patients were screened by interferon-gamma release assay and tuberculin skin tests using purified protein derivative. Results: The mean age of the patients was 39.91. The most common types of diseases were ankylosing spondylitis (37.6%) and RA (34.9%). The prevalence rate of LTBI was 12.1% among rheumatic patients. The patients with positive LTBI had significantly longer therapy duration (4.51 vs. 2.81 years, P< 0.001) and were older (48.61 vs. 38.72 years, P= 0.005), respectively. There was no statistically significant association between the disease types and LTBI positivity (P = 0.512). However, LTBI positive was more prevalent in patients who received rituximab (16.7%; P= 0.035) and those patients with past medical history (20.9% vs. 8.5%, respectively; P= 0.035) and those did not receive the bacillus Calmette–Guérin vaccination (36.4% vs. 10.1%; P= 0.029). Conclusions: This study suggests that patients with rheumatoid diseases and treated with anti-tumor necrosis factor therapies are at an increased risk of tuberculosis infection.