Negative Screening Does Not Rule out the Risk of Tuberculosis in Patients with Inflammatory Bowel Disease Undergoing Anti-TNF Treatment: A Descriptive Study on the GETAID Cohort

AIM to describe the characteristics of incident cases of tuberculosis [TB] despite negative TB screening tests, in patients with inflammatory bowel disease [IBD] undergoing anti-TNF treatment, and to identify the risk factors involved. METHODS A retrospective descriptive study was conducted at GETAID centers on all IBD patients undergoing anti-TNF treatment who developed TB even though their initial screening test results were negative. The following data were collected using a standardized anonymous questionnaire: IBD, and TB characteristics and evolution, initial screening methods and results, and time before anti-TNF treatment was restarted. RESULTS A total of 44 IBD patients [including 23 men; median age 37 years] were identified at 20 French and Swiss centers at which TB screening was performed [before starting anti-TNF treatment] based on Tuberculin Skin Tests [n = 25], Interferon Gamma Release Assays [n = 12], or both [n = 7]. The median interval from the start of anti-TNF treatment to TB diagnosis was 14.5 months (interquartile range [IQR] 25-75: 4.9-43.3). Pulmonary TB involvement was observed in 25 [57%] patients, and 40 [91%] had at least one extrapulmonary location. One TB patient died as the result of cardiac tamponade. Mycobacterium tuberculosis exposure was thought to be a possible cause of TB in 14 cases [32%]: 7 patients [including 6 health care workers] were exposed to occupational risks, and 7 had travelled to endemic countries. Biotherapy was restarted on 27 patients after a median period of 11.2 months [IQR 25-75: 4.4-15.2] after TB diagnosis without any recurrence of the infection. CONCLUSION Tuberculosis can occur in IBD patients undergoing anti-TNF treatment, even if their initial screening results were negative. In the present population, TB was mostly extrapulmonary and disseminated. TB screening tests should be repeated on people exposed to occupational risks and/or travelers to endemic countries. Restarting anti-TNF treatment seems to be safe.