全血γ-干扰素释放试验与ELISA检测结核分枝杆菌抗体在痰菌阴性肺结核辅助诊断中的比较应用

目的：探讨γ-干扰素释放试验（interferon-gamma release assays, IGRA）与酶联免疫吸附试验（enzyme linked immunosorbent assay, ELISA）在痰菌阴性肺结核诊断中的应用价值。方法：收集93例痰菌阴性肺结核患者和40例健康体检者的肝素钠抗凝全血,采用IGRA试剂盒检测其血浆γ-干扰素含量,其血清标本应用ELISA试剂盒检测结核分枝杆菌抗体（Tuberculosis antibody, TBAb）,并将2种结果进行比较分析。将痰菌阴性肺结核患者分为老年组和中青年组进行比较,分析IGRA检测在不同年龄段间是否有差异。结果：IGRA诊断痰菌阴性肺结核,灵敏度为84.94%,特异度为90.00%,阳性预测值为95.18%,阴性预测值为72.00%;TBAb诊断痰菌阴性肺结核灵敏度为52.69%,特异度为85.00%,阳性预测值为67.20%,阴性预测值为40.96%。2种方法相比较,差异有统计学意义。不同年龄患者间,IGRA检测结果差异无统计学意义。结论：与ELISA相比,IGRA对诊断痰菌阴性肺结核有更高的灵敏度、特异度和阳性预测能力。

Comparison and application of whole blood interferon-gamma release assays and ELISA for detection of antibodies against Mycobacterium tuberculosis in auxiliary diagnosis of bacterium-negative pulmonary tuberculosis

Objective: To investigate the value of interferon gamma release (IGRA) in the diagnosis of bacterial-negative pulmonary tuberculosis. Methods: A total of 93 patients with bacterial-negative tuberculosis and 40 healthy volunteers were enrolled in this study. Heparin sodium anticoagulant whole blood was collected. IGRA kit was used to detect the plasma IFN-γ level. Serum samples were collected for detection of Mycobacterium tuberculosis antibody(TBAb) by ELISA kit. Patients were divided into the elderly group and the young group for comparative analysis. Routine test indice ADA, erythrocyte sedimentation rate and lymphocyte count were performed. Results: The positive rate of IGRA was 84.94%, the sensitivity was 84.94%, the specificity was 90.00%, the positive predictive value was 95.18% and the negative predictive value was 72.00%. The positive rate of TBAb diagnosis was 52.69%, the sensitivity was 52.69%, the specificity was 85.00%, the positive predictive value was 67.20% and the negative predictive value was 40.96%. Rate of diagnosing tuberculosis using two methods, was statistically significant. There was no difference in age when using IGRA assays. There was significant differences in erythrocyte sedimentation rate between the two groups. Conclusion: Compared with ELISA, IGRA has higher sensitivity, specificity and positive predictive for diagnosing bacterium negative tuberculosis.