Abstract:

Objective: To evaluate the performance of a domestically produced Mycobacterium tuberculosis (MTB) T-cell immune response test kit (referred to as the “test kit”) for in vitro qualitative detection of MTB-specific T-cell immune responses in fresh peripheral venous anticoagulated blood from suspected tuberculosis patients. Methods: A comparative study was conducted using the domestic test kit and an already marketed imported product (referred to as the “control kit”). The study included 335 suspected tuberculosis patients treated at the Shaanxi Provincial Tuberculosis Hospital from November 2020 to June 2021, and 343 suspected tuberculosis patients treated at the First Affiliated Hospital of the Fourth Military Medical University from July 2021 to June 2022. Results: Among the 678 peripheral venous anticoagulated blood samples, using the control kit as the reference standard, the test kit showed a sensitivity of 93.97% (327/348), a specificity of 96.06% (317/330), and an overall agreement rate of 94.99% (644/678). When using pathogen diagnosis and clinical diagnosis as reference standards, the test kit showed a sensitivity of 82.93% (277/334), a specificity of 81.69% (281/344), and an overall agreement rate of 82.30% (558/678). In comparison, the control kit showed a sensitivity of 87.13% (291/334), a specificity of 83.43% (287/344), and an overall agreement rate of 85.25% (578/678). Among the 204 peripheral venous anticoagulated blood samples from pathogen-positive patients, the tuberculosis detection rate was 82.35% (168/204) for the test kit and 88.24% (180/204) for the control kit. Among the 130 peripheral venous anticoagulated blood samples from pathogen-negative patients, the tuberculosis detection rate was 83.85% (109/130) for the test kit and 85.38% (111/130) for the control kit. For the 344 peripheral venous anticoagulated blood samples from patients with non-tuberculous pulmonary diseases, the agreement rate between the two kits was 95.35% (328/344). The specificity was 81.69% (281/344) for the test kit and 83.43% (287/344) for the control kit. Conclusion: The domestic MTB T-cell immune response test kit demonstrates high consistency with the marketed imported kit for in vitro detection of MTB-specific T-cell immune responses in fresh peripheral venous anticoagulated blood from suspected tuberculosis patients. It can be considered a viable alternative diagnostic tool for suspected tuberculosis patients.

Key words: Tuberculosis, Enzyme-linked immunosorbent assay, Reagent kits, diagnostic, Sensitivity and specificity