title: Levels of interferon-gamma increase after treatment for latent tuberculosis infection in a high-transmission setting.
abstract: Objectives. We investigated IFN-γ levels before and after a six month course of isoniazid among individuals with latent tuberculosis infection (LTBI) in a high-transmission setting. Design. A total of 26 household contacts of pulmonary tuberculosis patients who were positive for LTBI by tuberculin skin test completed six months of treatment and submitted a blood sample for a follow-up examination. The IFN-γ response to Mycobacterium tuberculosis-specific antigens was measured, and the results before and after the completion of LTBI treatment were compared. Results. Of the 26 study participants, 25 (96%) showed an IFN-γ level higher than their baseline level before treatment (P ≤ 0.001). Only one individual had a decreased IFN-γ level after treatment but remained positive for LTBI. Conclusion. In a high-transmission setting, the IFN-γ level has increased after LTBI treatment. Further studies must be undertaken to understand if this elevation is transient.
authors: Advanced Laboratory of Public Health, Oswaldo Cruz Foundation, Gonçalo Moniz Research Center, Salvador, Bahia 40296 710, Brazil.
authors: Iukary
authors: I
authors: Takenami
authors: Brook
authors: B
authors: Finkmoore
authors: Almério
authors: A
authors: Machado
authors: Krisztina
authors: K
authors: Emodi
authors: Lee W
authors: LW
authors: Riley
authors: Sérgio
authors: S
authors: Arruda