P348. Retesting for latent tuberculosis in patients with inflammatory bowel disease after exposure to biologics
P. Papay1, C. Primas2, A. Eser1, S. Winkler3, G. Novacek1, S. Angelberger1, A. Mikulits1, H. Vogelsang1, W. Reinisch1
1Medical University Vienna, Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Vienna, Austria; 2Medical University of Vienna, Div. Of Gastroenterology and Hepatology, Vienna, Austria; 3Medical university of Vienna, Deparment of Internal Medicine I, Division of Infectious Diseases, Vienna, Austria
Background: Patients treated with TNF‑α inhibitors (TNFi) are at high risk of reactivation of latent tuberculosis (TB). Prospective studies on monitoring for TB reactivation and/or infection in this risk group are lacking.
Methods: We retested consecutive patients with inflammatory bowel disease (IBD) under therapy with TNFi for a minimum of 5 months for latent TB by interferon-γ release assay (IGRA) and tuberculin skin test (TST). From each subject a detailed patient history and concomitant therapy were captured.
Results: 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) initially screened for latent TB and subsequently treated with TNFi. Additionally TST was re-administered in 144/227 subjects (63.4%). The majority of patients was TNFi naïve (147/227, 79.9%). In 32 subjects isoniazid was provided prior and concurrently to TNFi due to latent TB. In this subgroup retesting for latent TB resulted in a reversion to negative in 6/13 patients (46.2%) and in 3/24 patients (12.5%, P = 0.08) with a positive IGRA and positive TST at baseline, respectively. In patients without latent TB at baseline no permanent IGRA conversion, but 6/144 (4.2%) TST conversions from negative to positive were observed. No single case of TB reactivation or infection was observed during the observation period.
Conclusions: A conversion of IGRA during treatment with anti-TNF‑α agent was not observed, but occurred for TST. IGRA frequently reverts to negative in patients with latent TB after specific therapy and seems to be a sensitive method to monitor patients for latent TB under treatment with TNFi.