QuantiFERON-TB Gold in the diagnosis of active tuberculosis.

QuantiFERON-TB Gold (QFT) is an indirect diagnostic test for latent tuberculosis (TB) infection and active TB. This study aimed to evaluate and compare QFT and the tuberculin skin test (TST) for the diagnosis of active TB disease, not bacteriologically verified at the time of therapy initiation. Seventy-three patients with suspected active TB were examined. Further diagnostic steps confirmed the diagnosis of active TB in 53 persons. QFT was positive in 43 persons (81%), negative in seven (13%), and indeterminate results were found in three (6%). The sensitivity of the test was 86% in those with valid results, significantly higher than that for the TST (62%), and the correlation between the two tests was not high (55%). The QFT test is a useful addition to existing methods for the diagnosis of active TB.