γ-干扰素释放实验联合Xpert MTB/RIF诊断低CD4+T淋巴细胞计数艾滋病合并肺结核病效能OA

Objective To evaluate the clinical efficacy of interferon-γ(IFN-γ)release assay(IGRA)combined with real-time fluorescence quantitative nucleic acid amplification assay(Xpert MTB/RIF)in the diagnosis of pulmonary tuberculosis in AIDS patients with low CD4+T lymphocyte counts.Methods A total of 140 AIDS patients with low CD4+T counts admitted to Hengshui Second People's Hospital from January 2023 to January 2025 were selected as the research subjects.Based on PTB status,patients were divided into a non-tuberculosis group(26 cases without tuberculosis),a bacteria-negative group(68 cases with bacteria-negative tuberculosis),and a bacteria-positive group(46 cases with bacteria-positive tuberculosis).Blood IFN-γ levels were compared among the three groups,and the detection rates of IGRA,Xpert MTB/RIF,and their combination were analyzed.Baseline characteristics were compared between IGRA-negative and IGRA-positive patients.Patients were further stratified into three subgroups based on CD4+T-cell count:＜50 cells/μL,50～99 cells/μL,and 100～199 cells/μL.Detection rates of the three diagnostic strategies were compared across subgroups.Agreement between each diagnostic strategy and the final clinical diagnosis was assessed.ROC curve was used to analyze the diagnostic value of each strategy for patients with different CD4+T lymphocyte count levels.Results The detection rates of IGRA,Xpert MTB/RIF and their combination were significantly lower in the non-TB group compared to those in the negative bacteria group and the positive bacteria group(P＜0.05).The mycobacterial culture positivity rate was higher in the positive bacteria group than that in the non-tuberculosis group and the negative group(P＜0.05).Among the 68 patients with negative pulmonary tuberculosis,68(100.00％)had positive pathological findings.The IGRA-positive group was younger(P＜0.05)and had a higher proportion of patients with symptom duration＜1 month compared to the IGRA-negative group(P＜0.05).The detection rates of IGRA,Xpert MTB/RIF and their combination were significantly lower in the＜50 cells/μL subgroup compared to the 50～99 cells/μL and 100～199 cells/μL subgroups(P＜0.05).In AIDS patients with PTB and CD4+T-cell counts of 50～99 cells/μL or 100～199 cells/μL,all three diagnostic strategies showed good agreement with the clinical diagnosis(Kappa ≥ 0.75).For patients with counts＜50 cells/μL,agreement was moderate(0.4≤Kappa＜0.75).Conclusion The diagnostic accuracy of IGRA combined with Xpert MTB/RIF may be superior to either test alone.Diagnostic accuracy decreases with declining CD4+T-cell counts,yet the combined approach may retain a relative advantage.