Comparison of intracellular cytokine flow cytometry and an enzyme immunoassay for evaluation of cellular immune response to active tuberculosis.

A prospective cross-sectional blinded study of 28 patients (21 male and 7 female patients; mean age, 44 years) with suspected active tuberculosis (TB) attending a TB and chest clinic is described. Blood was taken for immune cell enumeration, a whole-blood enzyme-linked immunosorbent assay (ELISA) for the detection of gamma interferon (IFN-gamma) by the QuantiFERON-TB Gold (QFT-G) assay, and intracellular cytokine flow cytometry (ICC) analysis; and sputum was simultaneously taken for bacteriological culture for Mycobacterium tuberculosis. Twelve healthy subjects were included as controls.