Search

© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/., Background: Rheumatic diseases are associated with an increase in overall risks of tuberculosis (TB). The aim of this study was to evaluate the frequency of TB and the frequency of latent TB infection (LTBI), in clinical practice, for juvenile idiopathic arthritis (JIA) patients from high and low risk of TB incidence endemic countries. Methods: This is an international, multicenter, cross-sectional, observational study of data collection from Brazil and Registry of Portugal at REUMA.PT. The inclusion criteria were patients with Juvenile Idiopathic Arthritis (JIA) with age ≤ 18 years who underwent screening for Mycobacterium tuberculosis infection [tuberculin skin test (TST) and/or interferon gamma release assay (IGRA)]. Chest X-rays and history of exposure to TB were also assessed. Results: 292 JIA patients were included; mean age 14.3 years, mean disease duration 7.5 years, 194 patients (66.4%) performed only TST, 14 (4.8%) only IGRA and 84 (28.8%) both. The frequency of LTBI (10.6%) and TB was similar between the two countries. The reasons for TB screening were different; in Brazil it was performed more often at JIA onset while in Portugal it was performed when starting Disease Modified Anti-Rheumatic Drugs (DMARD) treatment (p < 0.001). Isoniazid therapy was prescribed in 40 (13.7%) patients (31 with LTBI and 9 with epidemiologic risks and/or due to contact with sick people). Only three patients (1%) developed active TB. Conclusion: We found nearly 10% of patients with LTBI, a small percentage of patients with treatment due to epidemiologic risks and only 1% with active TB. Distinct reasons and screening methods for LTBI were observed between the two countries.

Renal transplant recipients (RTRs), as all immunosuppressed patients, are at increased risk of reactivating latent tuberculosis infection (LTBI). Detecting LTBI in this population is therefore important to prevent active TB. The tuberculin skin test (TST) has a poor sensitivity in this setting.The aim of this prospective study was to compare the diagnostic performance of the TST and two interferon-γ release assays (IGRAs): T-SPOT.TB (Oxford Immunotec, Oxford, UK) and QuantiFERON Gold In-Tube (QGIT; Cellestis, Australia), performed simultaneously, for the detection of patients with risk factors for LTBI or a definite history of TB among RTRs under stable immunosuppression.Two hundred five patients (ages 59±13 years, tested 10.4±7.1 years after transplantation) were studied. Positivity rate was 4.5% for TST, 20.5% for T-SPOT.TB, and 23.5% for QGIT. Agreement between IGRAs was fair (κ=0.71). Sensitivity of T-SPOT.TB and QGIT for detection of prior active TB was 55.6% (95% confidence interval [CI], 21.2-86.3) and 44.4 (95% CI, 13.7-78.8), respectively. Sensitivity of both IGRAs for detection of risk factors for LTBI was 33.3% (95% CI, 19.6-49.5). Specificity was 85.5% (95% CI, 78.9-90.7) for T-SPOT.TB and 80.1% (95% CI, 72.9-86.2) for QGIT. Combining IGRAs did not significantly improve sensitivity.Because their sensitivity for detecting prior active TB and probable LTBI in RTRs is very low, IGRAs cannot be used to exclude LTBI. These results emphasize the limitations of IGRAs in the setting of chronic immunosuppressive therapy.