Abstract: Objective Exploring the diagnostic value of T-cell enzyme-linked immunospot assay (T-SPOT.TB) combined with rifampicin-resistant Mycobacterium tuberculosis real-time fluorescence quantitative nucleic acid amplification detection (XpertMTB/RIF) in geriatric AIDS patients with Mycobacterium tuberculosis(MTB) infection. Methods From May 2022 to May 2024, 86 elderly patients with AIDS suspected MTB in Hengshui Third People's Hospital were gathered and separated into AIDS complicated with MTB (research group) and AIDS without MTB (control group) according to the pathological examination results. MTB culture, T-SPOT.TB and XpertMTB/RIF were performed. Kappa analysis was applied to evaluate the consistency between T-SPOT.TB combined with XpertMTB/RIF and the gold standard for diagnosing MTB coinfection in AIDS patients. ROC curve and four grid table were plotted to analyze the value of the combination of T-SPOT.TB and XpertMTB/RIF in the diagnosis of AIDS complicated with MTB infection. Results The blood γ-interferon, the positive detection rates of T-SPOT.TB and XpertMTB/RIF in the research group were higher than those in the control group (P＜0.05). The AUC of T-SPOT.TB in diagnosing AIDS with MTB infection was 0.810, that of Xpert MTB/RIF in diagnosing AIDS with MTB infection was 0.835, and the AUC of the two in diagnosing AIDS with MTB infection was 0.910. The Kappa values of T-SPOT.TB, Xpert MTB/RIF and their combined diagnosis for AIDS with MTB infection were 0.624, 0.674 and 0.825, respectively. The accuracy of T-SPOT.TB in the diagnosis of AIDS with MTB was 82.56%, the accuracy of XpertMTB/RIF in the diagnosis of AIDS with MTB was 84.88%, and the accuracy of the combined diagnosis for AIDS with MTB was 91.86%. Conclusions T-SPOT.TB combined with XpertMTB/RIF can improve the accuracy of diagnosis of AIDS with MTB, and can be used as a clinical auxiliary diagnosis method for AIDS patients complicated with MTB.

Key words: T cell enzyme-linked immunospot assay, rifampicin-resistant real-time fluorescence quantitative nucleic acid amplification detection technology, acquired immunodeficiency syndrome, Mycobacterium tuberculosis