Post-treatment change in Mycobacterium tuberculosis antigen-stimulated tumor necrosis factor-alpha release in patients with active tuberculosis

The central dogma of protective immunity to Mycobacterium tuberculosis (MTB) is the interplay between MTB-infected macrophages and T cells, which is mediated by numerous cytokines produced by both cell types (1). In particular, CD4+ T cells play a major role by producing interferon-gamma (IFN-γ), which synergizes with tumor necrosis factor-alpha (TNF-α) and potentiates macrophages that are capable of restricting the growth of MTB (1,2). Thus, the evaluation of cytokine expression elicited by the cellular responses to MTB-specific antigen (Ag) has been exploited as one way to detect TB infection. As such, the interferon-gamma release assay (IGRA) has led to further advances in the diagnosis of TB infection