One of the adverse effects of the tumour necrosis factor alpha [[TNFα] monoclonal antibodies for the treatment of immune-mediated inflammatory diseases is a higher propensity for tuberculosis development. The aim of this study was to explore the utility and sensitivity of serial tuberculosis screening during anti-TNFα treatment.
A cohort of 46 inflammatory bowel disease patients receiving infliximab was prospectively recruited and followed for 26 months. During this period of time, a tuberculosis skin test and two different interferon ϒ release assays [QFT-GIT and T-SPOT.TB] were applied at 4-6-month intervals.
Overall, 16 patients were diagnosed with latent tuberculosis infection after having at least one test conversion: 12 patients had a positive tuberculosis skin test, seven patients had a positive T-SPOT.TB, and two patients had a positive QFT-GIT. Active tuberculosis was excluded in all; 15 were treated with isoniazid. A comparison between tests showed a moderate accuracy [72% to 85%] but low kappa values [0.063 to 0.377]. Concerning association with demographic and clinical characteristics, test conversion was more common among the male gender and those with a longer disease duration.
Tuberculosis tests conversions were common in inflammatory bowel disease patients treated with infliximab alone or in association with immunomodulators. In these immunosuppressed individuals, the classical tuberculosis skin test seems to have a higher sensitivity than the modern tests based on the release of interferonϒ.