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.