Diagnostic value of TB-IGRA combined with XpertMTB/RIF in AIDS patients with CD4+decline and pulmonary tuberculosis

Liu Can; Cao Yawei; Zhao Yue

doi:10.3969/j.issn.1674-3245.2025.03.014

Abstract：Objective To analyze the diagnostic value of tuberculosis-specific interferon-gamma release assay(TB-IGRA)combined with Xpert Mycobacterium tuberculosis/rifampicin(Xpert-MTB/RIF)in acquired immune deficiency syndrome(AIDS)patients with CD4+decline and pulmonary tuberculosis(PTB).Methods A retrospective analysis was conducted on the clinical data of 110 AIDS patients with suspected PTB who were admitted to the hospital from August 2021 to July 2024.The patients were grouped according to the gold standard of MTB culture and bacterial type identification.69 AIDS patients with PTB were included in the AIDS with PTB group,and 41 AIDS patients without PTB were included in the AIDS without PTB group.The diagnostic efficacy of TB-IGRA and Xpert MTB/RIF for PTB in AIDS was compared.Results Among the 110 AIDS patients,there were 69 patients with PTB and 41 patients without.In the diagnosis of AIDS complicated with PTB,TB-IGRA and Xpert MTB/RIF showed moderate consistency with the gold standard(Kappa=0.590,0.450).Combination of the two showed good consistency with the gold standard(Kappa=0.764).The accuracy rates of TB-IGRA,Xpert MTB/RIF,and their combination were 80.91％,74.55％and 89.09％.Comparison of the accuracy between TB-IGRA,Xpert MTB/RIF and combined detection found statistically significant differences(x2=7.763,P＜0.05).The sensitivity,specificity,accuracy and negative predictive value of combined detection(92.75％,82.93％,89.09％and 87.18％)were higher than those of Xpert MTB/RIF(81.16％,63.41％,74.55％and 87.18％)(x2=4.089,3.976,7.822,4.622,all P＜0.05).There were no statistically significant differences in the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value between TB-IGRA and Xpert MTB/RIF(P＞0.05).The AUC values of TB-IGRA and Xpert MTB/RIF for diagnosing AIDS complicated with PTB were 0.793 and 0.723,respectively.The combined AUC was 0.878.The sensitivity and specificity of combined diagnosis were 92.75％and 82.93％.The AUC of combined diagnosis was higher than that of separate diagnosis(Z=7.153,4.968,both P＜0.05).Conclusion TB-IGRA and Xpert MTB/RIF both demonstrate significant diagnostic value in AIDS patients with PTB and CD4+＜200 cells/μl.The combined assay significantly improves diagnostic accuracy.