T细胞酶联免疫斑点试验在HIV感染合并结核潜伏性感染筛查诊断中的研究

Exploratory study on an enzyme-linked immunospot assay for diagnosing latent tuberculosis infec-tion in HIV-positive individuals

目的：探讨T细胞酶联免疫斑点试验（ TSPOT）在人类免疫缺陷病毒（ HIV）感染人群中诊断结核潜伏性感染的应用价值。方法用TSPOT试剂盒检测380例明确诊断的HIV感染者进行结核分枝杆菌（ Mtb）特异性T细胞的检测,同时对所有入组病例进行结核菌素纯蛋白生物（ PPD）试验和流式细胞术检测外周血CD4细胞计数水平。结果在HIV感染者总体、CD4〉200/μl和CD4〈200/μl的各组中,TSPOT检测阳性率分别为57.4%、72.2%和67.3%,均显著高于相应的PDD试验结果（36.8%,27.7%,32.6%）。同时,进一步分析发现TSPOT检测结果与患者外周血CD4＋T淋巴细胞计数水平无关。结论 TSPOT检测在我国HIV感染合并结核潜伏感染的筛查诊断中有较大的应用价值。

Objective To investigate the application of a new enzyme-linked immunospot assay （TSPOT-TB） in diagnosing latent tuberculosis（TB） infection in HIV-positive individuals. Methods The TSPOT-TB assay was employed to detect ESAT-6-and CFP-10-specific T cells in blood samples from 380 HIV-positive individuals. Simultaneously, a PPD skin test and flow cytometry of CD4 cell counts were performed on all patients. Results Using the TSPOT-TB assay, positivity rates for the total 380 HIV-positive individuals, individuals with CD4 cell counts greater than 200/μl and individuals with CD4 cell counts less than 200/μl were 57. 4%, 72. 2% and 67. 3%, respectively. The positive rates of the PPD skin test were 36. 8%, 27. 7% and 32. 6% in these three groups, respectively. These results indi-cate that the positive rates obtained from the use of the TSPOT-TB assay were all significantly higher than those obtained from the PPD skin test （P〈0. 05）. Furtherly, the CD4 cell counts had no effect on the results of TSPOT-TB assay. Conclusions The TSPOT-TB assay will be a useful tool in screening diagno-sis of latent tuberculosis infection in HIV-positive individuals in China.