Abstract
INTRODUCTION: No direct comparative study assessing QuantiFERON-TB Gold In-Tube (QFT-GIT) and QuantiFERON-TB Gold Plus (QFT-Plus) for Mycobacterium tuberculosis infection among persons living with HIV (PLHIV) in China has been conducted. METHODS: Simultaneous QFT-GIT and QFT-Plus tests were conducted on PLHIV in a prison hospital. Positivity and negativity results from both assays were compared, and their diagnostic agreement was assessed. RESULTS: A total of 232 PLHIV individuals were included in this study. Among them, 57 patients (24.6%) and 56 patients (24.1%) were diagnosed with Mycobacterium tuberculosis infection based on QFT-GIT results and QFT-Plus, respectively. The overall agreement between the two assays was 98.3%, with a Cohen's kappa value of 0.954. Consistency rates were observed between QFT-GIT plus, QFT-Plus TB1 and TB2 with QFT-GIT were 98.3%, 97.4% and 97.8%. The IFN-γ levels measured in QFT-GIT were found to surpass those in QFT-Plus TB1 (P = 0.04), while the difference compared to QFT-Plus TB2 exhibited a marginal trend (P = 0.134). Among the subgroup of 52 individuals who underwent dual QFT-GIT tests, a significant proportion of 23.1% (12 individuals) experienced a change in their QFT-GIT results, transitioning from a positive to a negative outcome. CONCLUSIONS: The diagnostic performance of QFT-GIT and QFT-Plus for Mycobacterium tuberculosis infection among PLHIV with relatively higher CD4 counts was found to be comparable. Additionally, our investigation revealed that irrespective of the treatment regimen, whether it involved chemotherapy or immunotherapy, preventive Mycobacterium tuberculosis infection interventions among PLHIV consistently led to a reduction in IFN-γ levels.