Evaluation of Mycobacterium tuberculosis specific antigen-stimulated CD27(−)CD38(+)IFN-γ(+)CD4(+) T cells for discrimination of active tuberculosis

BACKGROUND: Active tuberculosis (ATB) originates from primary Mycobacterium tuberculosis (MTB) infection or reactivation of latent tuberculosis. Besides bacteriological examination, MTB-reactive immunocytes detection can be an alternative testing for discrimination of active tuberculosis. The purpose of this study is to investigate the accuracy of peripheral blood CD27(−)CD38(+)IFN-γ(+)CD4(+)T cells in ATB diagnosis. METHODS: This prospective diagnostic accuracy study was conducted at Shanghai Pulmonary Hospital between January 2019 and December 2021. Patients with ATB, non-tuberculosis mycobacterium infection (NTM), latent tuberculosis infection (LTBI), other respiratory diseases (OD), and healthy individuals (HC) were enrolled. The accuracy of CD27(−)CD38(+)IFN-γ(+)CD4(+)/CD4(+) and other phenotypic markers for ATB diagnosis was assessed. RESULTS: A total of 376 patients (237 ATB, 38 LTBI, 8 NTM, 50 OD, and 43 HC) were enrolled. The ratios of CD4(+)IFN-γ(+)CD27(−) and CD4(+)IFN-γ(+)CD27(−)CD38(+) profiles in CD4(+)IFN(−)γ(+) cells and the ratios of CD4(+)IFN-γ(+)CD38(+), CD4(+)IFN-γ(+)CD27(−), and CD4(+)IFN-γ(+)CD38(+)CD27(−) profiles in CD4(+) cells in the ATB group were significantly higher than in the other groups. The area under the curve (AUC) of CD27(−)CD38(+)IFN-γ(+)CD4(+)/CD4(+) for the diagnosis of ATB was the highest, with a value of 0.890. With the optimal cutoff value of 1.34 × 10(–4), the sensitivity and specificity of CD27(−)CD38(+)IFN-γ(+)CD4(+)/CD4(+) for ATB diagnosis was 0.869 and 0.849, respectively. CONCLUSION: CD27(−)CD38(+)IFN-γ(+)CD4(+)/CD4(+) might be a potential biomarker for active tuberculosis diagnosis.