Mycobacterial Diseases
Open Access

Abstract

The Quantiferon^®-TB Gold In-Tube Assay Detects Interferon-Γ Release Responses to Mycobacterium Tuberculosis Antigens for Extended Periods of Time

Takashi Hirama, Shohei Minezaki, Minoru Kanazawa, Hidetoshi Nakamura and Makoto Nagata

The development and wide usage of interferon (IFN)-γ release assays (IGRAs) brought remarkable advances in the diagnosis of tuberculosis (TB). QuantiFERON®-TB Gold In-Tube (QFT-GIT), one of the IGRAs, employs three TB antigens, ESAT-6, CFP-10, and TB7.7, to which cell-mediated immune responses are measured in a single tube. In this regard, the QFT-GIT in patients with active TB was hypothesized to detect TB positivity for a longer period after the initiation of treatment. The change of IFN-γ values in patients with pulmonary TB serially registered to the study was examined with QFT-GIT before initiating anti-TB drugs, after completion of treatment and 12 months after the cessation of treatment. The data demonstrates that the IFN-γ levels remained consistently positive for a period of one year after treatment.