T细胞酶联免疫斑点法对风湿性疾病患者潜伏性结核感染诊断价值的初步研究

Enzyme-linked immunospot assay for the diagnosis of latent tuberculosis infection in rheumatic diseases

目的探讨T细胞酶联免疫斑点法（TSPOT）对风湿性疾病患者潜伏结核感染的诊断价值。方法应用TSPOT—TB试剂盒对126例明确诊断的风湿性疾病患者血液标本进行结核分枝杆菌（Mtb）特异性T细胞应答的检测，同时对所有病例做结核菌素纯蛋白衍生物（PPD）试验进行联合分析。结果TSPOT检测阳性率23．8％，PPD试验阳性率为34．9％，两者一致率为71．4％。其中PPD（-）者中11例TSPOT（＋），占13．4％；PPD（＋）中有25例TSPOT（-），占56．8％。有卡介苗接种史的患者PPD试验的阳性率显著高于无卡介苗接种史的患者（41％与19％，P〈0．05），但有无卡介苗接种史的两组患者在TSPOT检测的阳性率上差异无统计学意义（22％与27％，P〉0．05）。结论卡介苗接种影响风湿性疾病患者PPD试验的结果，但对TSPOT检测结果未造成影响。TSPOT技术检测显示本研究风湿性疾病患者中的结核潜伏感染率为23．8％。

Objective To evaluate a new enzyme-linked immunospot assay （TSPOT-TB） for the diagnosis of latent tuberculosis infection in patients with rheumatic diseases. Methods The rapid TSPOT-TB assay was applied to detect ESAT-6 and CFP-10 specific T cells in blood samples from 126 rheumatic disease patients. A PPD skin test was performed on all patients simultaneously. Results The positive rate of TSPOT assay was 23.8% and that of PPD skin test was 3d.9%.The overall agreement between the 2 tests was 71.4%. Among PPD（-） patients （n=82）, 11 were TSPOT（＋） （13.4%）. Among PPD（＋） patients （n=44）, 25 were TSPOT（-） （56.8%）. The patients who got BCG vaccination showed a significantly higher rate of positive results of PPD skin test than those who did not（41% vs 19%, P〈0.05）. While in TSPOT assay, the BCG vaccina-tion did not show any influence on TSPOT results （22% vs 27%, P〉0.05）. Conclusion BCG vaccina-tion affects the results of PPD test in patients with rheumatic diseases, but has no influence on TSPOT results. The infection rate of latent tuberculosis in patients with rheumatic diseases in our study is 23.8% detected by TSPOT.