Risk factors for false-negative results of QuantiFERON-TB Gold In-Tube assay in non-HIV-infected patients with culture-confirmed tuberculosis.

Abstract

Limited information is available on the risk factors for false-negative results with the new generation of QuantiFERON-TB Gold In-Tube (QFT-GIT) tests in non-HIV-infected patients with tuberculosis (TB). We sought to identify risk factors for false-negative QFT-GIT results in culture-confirmed TB patients. We reviewed the microbiological, laboratory, radiographic, and clinical data of 362 patients with positive M. tuberculosis cultures who received QFT-GIT tests at a Korean tertiary hospital between September 2006 and March 2010. Of these, 311 (85.9%) had true-positive and 51 (14.1%) had false-negative results. The false-negative group was more likely to have immunosuppressant diseases and lower platelet, protein, and albumin levels than the true-positive group. An immunosuppressive condition was an independent risk factor for false-negative QFT-GIT results in non-HIV-infected patients with active TB (odds ratio, 2.98; 95% confidence interval, 1.38-6.47; P = .006). Careful interpretation of negative QFT-GIT results is thus necessary in immunocompromised patients suspected of having active TB