Development of tuberculosis in immunocompromised patients with a positive tuberculosis-specific IGRA.

There is a lack of data on the predictive value of tuberculosis (TB) specific interferon-gamma release assays (TIGRAs) for both immunocompetent and immunocompromised individuals. We retrospectively followed up 460 such patients after QuantiFERON®-TB Gold In-Tube (QFT-GIT) testing (mean follow-up 28 months) by reviewing patient charts. A total of 1/38 QFT-GIT-positive and no QFT-GIT-negative patients developed active TB. The incidence rate of progression to active TB assessed retrospectively in these patients after positive TIGRA was therefore low (1.2 events/100 person-years). The need for careful follow-up and prophylactic therapy after positive TIGRA in this patient group needs to be evaluated prospectively.