Prevalence of latent tuberculosis infection determined by interferon-gamma release assays in patients with immune-mediated diseases

Background Patients with Immune-mediated inflammatory diseases (IMIDs) are at high risk of reactivation of tuberculosis, the risk is determined on the type of drug disease-modifying antirheumatic drugs (DMARDs). The objective of this study was to determine the prevalence of latent tuberculosis infection (LTBI) and associated factors in people who started or who were on DMARDs treatment. Methods A cross-sectional study was conducted in Mexico City from January 2021 to June 2024. People ≥ 18 years old, in the clinic of IMIDs, on mainly biological DMARDs treatment or before it was started. The prevalence of LTBI was determined by gamma interferon release assay (QuantiFERON-TB Gold Plus). Categorical data were expressed as frequencies and percentages, quantitative data in median and interquartile ranges, prevalence of LTBI was presented as percentage. A bivariate analysis was performed with x ² test to identify associated factors. A multivariate analysis was performed using a logistic regression model. Results A total of 304 patients were analyzed, 154 (50.7%) were men, with median age of 53 (IQR 39–61) years. Prevalence of LTBI was 34.2% (95% CI 29.1%-39.7%). The most frequent IMIDs were psoriasis in 123 (40.4%) and, rheumatoid arthritis in 47 (15.4%). The most prescribed biological DMARDs were adalimumab in 132 (43.4%) and secukinumab in 46 (15.1%). After a logistic regression model, prior exposure to contacts diagnosed with tuberculosis OR 4.20 (95% CI 1.74–10.12, p = 0.001) and TST ≥ 5 mm OR 99.3 (95%CI 12.7-773.2) remain statistical significance. Conclusions A high prevalence of LTBI was found in patients with IMIDs treated with biological DMARDs. tumor necrosis factor alpha inhibitors were widely prescribed in these patients. The history of exposure to contacts diagnosed with tuberculosis and TST ≥ 5 mm were associated with positive IGRA for LTBI.