Background: Whether T-cell interferon-γ responses to Mycobacterium tuberculosis-specific antigens can be influenced by tuberculosis preventive treatment in a high-endemic country is uncertain.
Methods: In this prospective, open-label, controlled study, 513 individuals with silicosis were randomly selected for TB preventive treatment with rifapentine and isoniazid or for observation. QuantiFERON-TB Gold in-tube (QFT-GIT) assay was used to measure IFN-γ response to M. tuberculosis antigens at baseline (T0) and at 6 (T1) and 33 (T2) months after completion of therapy.
Results: A total of 220 subjects were included in the final analysis: 105 and 115 in the prevention and observation arms, respectively. The proportions of QFT-GIT reversion from baseline to T1 were similar in the prevention and observation arms (18.4% vs 12.8%, P=0.566). However, reversion from baseline to T2 was more frequent in the prevention arm than in the observation arm, but the difference was not significant (24.2% vs 6.3%, P=0.881). No significant difference was observed in the quantitative responses of QFT-GIT between the two arms during follow-up at T1 (P=0.648) and T2 (P=0.918).
Conclusions: Preventive tuberculosis treatment has no effect on interferon-γ responses measured by serial QFT-GIT assays in a high tuberculosis-endemic country.
Clinical trials registration: http://www.clinicaltrials.gov NCT02430259.
Keywords: QuantiFERON TB-Gold in-tube; Randomized clinical trial; Serial tests; Tuberculosis preventive treatment.
Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.