探讨γ-干扰素释放试验在HIV/AIDS患者中的结核病诊断价值

目的 探讨γ-干扰素释放试验（IGRA试验）在HIV/AIDS患者中诊断结核病应用价值及CD4⁺T淋巴细胞对IGRA试验结果影响程度。方法 选取789例HIV/AIDS患者血标本和痰标本,进行IGRA试验、CD4⁺T淋巴细胞计数及结核分枝杆菌培养,并对检测结果加以分析。结果 789例HIV/AIDS患者中,结核分枝杆菌培养阳性有42例,其中 IGRA阳性率为50.00%（21/42）;HIV/AIDS合并活动性肺结核患者中,结核分枝杆菌培养阳性率为29.20%(33/113),IGRA阳性率为30.09%（34/113）;无肺结核主要临床症状和胸片无肺结核病灶的HIV/AIDS患者中,结核分枝杆菌培养阳性率为1.22%（6/490）,IGRA检测阳性率为26.94%（132/490）;在CD4⁺T淋巴细胞等级计数≥300个/mm³组、200~<300个/mm³组、100~<200个/mm³组及0~<100个/mm³组中,IGRA阳性率分别为30.58%、20.18%、25.42%、17.02%,IGRA阳性率有随CD4⁺T淋巴细胞计数降低而降低的趋势（χ²=14.852,P<0.05）;IGRA结果不确定率分别为5.81%、10.09%、9.32%、20.43%, IGRA结果不确定率有随CD4⁺T淋巴细胞计数降低而增高的趋势（χ²=30.021,P<0.05）。结论 IGRA试验作为HIV/AIDS感染者合并结核病的辅助诊断有一定临床使用价值,但作用非常有限,患者免疫力下降对IGRA试验结果影响较大,出现不确定性结果也随着免疫力下降而增高。

Diagnostic value of IGRA for tuberculosis in HIV/AIDS patients

Objective To discuss the application of interferon-gamma release assays (IGRAs)in the detection of HIV infected person, and the effect of CD4T lymphocytes on IGRA results. Methods The blood and sputum samples of 789 patients with HIV/AIDS were selected for IGRA test, the count of CD4T lymphocyte and the culture of Mycobacterium tuberculosis (MTB), and the result was analyzed. Results Among the 789 HIV/AIDS patients,42 cases were cultured positive of MTB, and the positive rates of IGRA in these 42 cases was 50.00%(21/42).Among the TB/ HIV(AIDS) co-infection patients, the positive rate of sputum culture was 29.20%(33/113) and the positive rate of IGRA was 30.09%(34/113). The positive rate of MTB culture was 1.22% (6/490) and the positive rate of IGRA was 26.94% (132/490) in HIV/AIDS patients without pulmonary tuberculosis main clinical symptoms and without pulmonary tuberculosis lesions in chest radiography.The positive rate of IGRA were 30.58%, 20.18%, 25.42%, 17.02%, respectively in 300 cells /mm³ group, 200 cells /mm³ group, 100 cells /mm³ group and 0 cells /mm³ group of CD4⁺T lymphocyte grade count, the positive rate of IGRA decreased with the decrease of CD4T lymphocyte count (χ²=14.852, P<0.05); the uncertainty rates of IGRA were 5.81%, 10.09%, 9.32% and 20.43%, respectively in the above 4 groups. The uncertainty rate of IGRA increased with the decrease of CD4 cells count (χ²=30.021, P<0.05). Conclusions IGRA can be used as an auxiliary diagnosis of HIV/AIDS infected patients with tuberculosis, but its effect is very limited. Patients' immunity has a great impact on the results of the IGRA, and the uncertainty results increase with the decline of immunity.