Diagnostic Performance of Interferon-Gamma Releasing Assay in HIV-Infected Patients in China

Yanhua Yu,Wei Li,Ting Wei,Xiuying Zhao,Ming Chen,Yanmei Jiao,Guizhen Sun,Hao Wu,Huizhu Wang,Wen Wang,Wenhao Hua,Yuxian He

doi:10.1371/journal.pone.0070957

Abstract

BackgroundActive tuberculosis infection represents a very common and significant threat to HIV-infected patients. But measures to accurately detect it are limited.ObjectiveTo compare and analyze the diagnostic efficacy of T-SPOT.TB alone and in combination with TST in HIV-infected patients in China.MethodTST (tuberculin skin test) and T-SPOT.TB were performed on 131 HIV-infected patients admitted in Beijing You’an Hospital and Beijing Ditan Hospital between Oct, 2010 and Jul, 2012, who were initially diagnosed as suspected ATB (active TB). The patients were further categorized into ATB and Not ATB based on clinical and cultural evidences. The performance of TST and T-SPOT.TB were analyzed and compared.ResultsThe sensitivity and specificity of T-SPOT.TB were 41.3% and 94.6%, respectively, both higher than TST (12.9% and 91.8%). By combining T-SPOT.TB and TST, the sensitivity did not increase, but specificity was elevated to 100%. TST, T-SPOT.TB and their combinations all performed better in patients with extra-pulmonary diseases than with pulmonary disorders. False-positive T-SPOT.TB results were found to be associated with history of prior TB. In addition, concomitant bacterial infections and low CD4 counts were associated with increased ATB risk.ConclusionsT-SPOT.TB is superior in screening ATB in HIV-infected patients in China over traditional TST. Additional TST would help to confirm a positive T-SPOT.TB result. Both tests work better for patients with extra-pulmonary conditions.

Highlights

Tuberculosis (TB) is one of the most historical and common infectious diseases in the world
T-SPOT.TB is superior in screening active tuberculosis (ATB) in HIV-infected patients in China over traditional TST
Despite the widely used Bacille Calmette-Guerin (BCG) vaccine, around one third of the global population are infected with Mycobacterium tuberculosis (M.TB) according to the report from the World Health Organization (WHO) [1]

Summary

Introduction

Tuberculosis (TB) is one of the most historical and common infectious diseases in the world. Despite the widely used Bacille Calmette-Guerin (BCG) vaccine, around one third of the global population are infected with Mycobacterium tuberculosis (M.TB) according to the report from the World Health Organization (WHO) [1]. Most of the TB patients are in developing countries, including China. The incidence of active tuberculosis (ATB) is doubled and death rate rises 7-fold in the past decade in China [2]. The risk of the progression of latent TB infection to active diseases is around 5–10% [3]. The most important risk factor is HIV infection [4,5]. The risk of progression to active TB is 10% in HIV-infected patients [6]. Active tuberculosis infection represents a very common and significant threat to HIV-infected patients.

Methods

Results

Conclusion