Retesting for latent tuberculosis in patients with inflammatory bowel disease treated with TNF-alpha inhibitors

摘要

Patients treated with TNF-a inhibitors (TNFi) are at high risk of reactivation of latent tuberculosis (LTB). Prospective studies on monitoring of TB reactivation and/or infection in this risk group are lacking.To test the conversion and reversion rate of screening tests for latent TB serial tuberculin skin test (TST) and interferon-y release assay (IGRA) under ongoing TNFi therapy.We retested consecutive patients with IBD receiving TNFi therapy for a minimum of 5 months for LTB using IGRA and TST. A detailed patient history and concomitant therapy were recorded for each subject.After a median of 34.9 weeks (20.7-177.7), IGRA was retested in 184/227 patients (81.1%; Crohn's disease n = 139, ulcerative colitis n = 45) still under index TNFi. TST was available in 144/184 subjects (78.2%). The majority of patients were TNFi naive (147/184, 79.9%). In a subgroup of patients who received isoniazid due to diagnosis of latent TB at baseline in = 32), 6/13 patients (46.2%) with baseline positive IGRA and 3/22 patients (13.6%) with baseline positive TST reverted to negative at retesting. In patients without diagnosis of LTB at baseline no permanent IGRA conversion was observed, but there were 6/144 (4.2%) TST conversions from negative to positive. No single case of TB reactivation or infection was recorded during the observation period.During treatment TNF-a inhibitors conversion was observed for tuberculin skin test, but not interferon-y release assay. As compared with tuberculin skin test, interferon-y release assay reverted in nearly half of isoniazid-trea-ted patients for latent tuberculosis. However, the fact that patients in whom the interferon-y release assay test result remained positive did not develop active tuberculosis during follow-up questions the utility of interferon-y release assay as a monitoring tool during chemoprevention.