Tuberculosis infection in BCG vaccinated children and adolescents with rheumatological diseases treated by tumor necrosis factor-α inhibitors.

UNLABELLED: Tumor necrosis factor-alpha (TNF-α) inhibitors increase the risk of developing active tuberculosis (TB) disease through reactivation of latent TB infection (LTBI). We aimed to analyze TB infections in BCG-vaccinated children and adolescents with rheumatologic diseases treated with TNF-α inhibitors in a country of moderate risk for TB. This retrospective study included 261 children with a rheumatic disease who were treated with TNF-α inhibitors and followed up on a fixed schedule between January 2018 and December 2022. Demographic and clinical characteristics, as well as TB screening results, were recorded. The mean age of the patients was 14.0 ± 4.1 years; 56.7% were female. The mean age at initiation of TNF-α inhibitors was 11.0 ± 5.1 years, the mean duration of TNF-α inhibitor use was 4.1 ± 2.7 years, and the mean follow-up time was 4.1 ± 2.6 years. During the study period, 75 (29.0%) patients were diagnosed with LTBI: 44% at the initial evaluation and 56% during follow-up. None of them progressed to TB disease. Only two cases of active TB disease were seen without prior documented LTBI. Age and duration of TNF-α inhibitor use were significantly associated with LTBI positivity.

CONCLUSION:  TB screening is necessary in children and adolescents at the initiation of and during TNF-α inhibitor therapy. The risk of LTBI positivity increases with age and longer use of TNF-α inhibitors. No cases progressed from LTBI to active TB, which may support the effectiveness of current screening and prophylaxis strategies in our country.

WHAT IS KNOWN: • TNF-α inhibitors are associated with an increased risk of developing active tuberculosis (TB) disease as a result of the reactivation of latent TB infection (LTBI).

WHAT IS NEW: • Screening for LTBI at initiation and during TNF-α inhibitor treatment, along with appropriate LTBI prophylaxis, prevented LTBI reactivation into active TB disease in BCG-vaccinated patients receiving TNF-α inhibitors. • Increasing age and duration of TNF-α inhibitor treatment are associated with the risk of LTBI positivity.