γ-干扰素释放试验在诊断结核分枝杆菌感染中的应用价值

Application value of interferon γ-release assay in diagnosis of tuberculosis

目的回顾性分析γ-干扰素释放试验(IGRA)在结核病诊断中的应用价值。方法选择2018年1月—2019年6月甘肃省武威肿瘤医院收治的208例疑似结核病住院患者,采用IGRA检测患者的γ-干扰素释放量,以临床诊断为确诊标准,评价IGRA检测结果诊断结核病的敏感度、特异度、准确度、阳性预测值和阴性预测值,同时评价IGRA检测结果与结核分枝杆菌免疫球蛋白G(IgG)检测、结核分枝杆菌培养、结核分枝杆菌DNA检测以及结核涂片抗酸染色检测结果的一致性。结果IGRA检测、结核分枝杆菌IgG检测、结核分枝杆菌培养、结核分枝杆菌DNA检测、结核涂片抗酸染色诊断结核病的敏感度分别为86.14%、47.59%、54.82%、49.52%、29.52%,特异度分别为76.19%、85.71%、80.95%、83.87%、97.62%,准确度分别为84.13%、55.29%、60.10%、66.53%、43.27%,阳性预测值分别为93.46%、92.94%、91.92%、92.21%、98.00%,阴性预测值分别为58.18%、29.27%、31.19%、66.38%、25.95%。结核分枝杆菌IgG检测、结核分枝杆菌培养和结核涂片抗酸染色对结核病的诊断敏感度均明显低于IGRA检测(分别为47.59%、54.82%、29.52%比86.14%,均P<0.05)。结核分枝杆菌IgG检测和结核分枝杆菌培养对肺外结核的诊断敏感度明显低于IGRA检测(分别为18.52%、33.33%比85.19%,P<0.05)。结核病组和非结核病组的IGRA检测与结核分枝杆菌IgG检测结果比较差异均无统计学意义(χ^2值分别为0.004和1.685,均P>0.05),结核病组与非结核病组的IGRA检测与结核分枝杆菌培养结果比较差异均有统计学意义(χ^2值分别为6.326和3.848,均P<0.05),表明结核分枝杆菌IgG检测对结核病的诊断效能较弱。结论IGRA检测具有较高的敏感度和特异度,且阳性预测值和阴性预测值均明显高于结核分枝杆菌IgG检测、结核分枝杆菌培养和结核涂片抗酸染色,IGRA检测在结核病的诊断中具有较好的诊断价值,值得在临床推广应用。

Objective To retrospectively analyze the application value of interferon γ-release assay(IGRA)in the diagnosis of tuberculosis.Methods Two hundred and eight patients suspected of tuberculosis hospitalized in Gansu Wuwei Tumor Hospital from January 2018 to June 2019 were selected in this study,and the IGRA was used to detect the patients' γ-interferon release amount.The clinical diagnosis was recognized as the confirmed diagnosis standard to evaluate the degrees of sensitivity,specificity,accuracy,positive predictive value and negative predictive value for diagnosis of tuberculosis by IGRA detection results,and simultaneously,the application values of Mycobacterium tuberculosis IgG assay,Mycobacterium tuberculosis culture,Mycobacterium tuberculosis DNA assay and tuberculous bacillus smear acid-fast staining were evaluated and compared with the results of IGRA to show whether they were consistent.Results The sensitivities of IGRA,Mycobacterium tuberculosis IgG assay,Mycobacterium tuberculosis culture,Mycobacterium tuberculosis DNA assay and tuberculosis bacillus smear acid-fast staining for detection of tuberculosis were 86.14%,47.59%,54.82%,49.52% and 29.52%,respectively,the specificities were 76.19%,85.71%,80.95%,83.87%,and 97.62%,respectively,the accuracy degrees were 84.13%,55.29%,60.10%,66.53%,and 43.27%,respectively,the positive predictive values were 93.46%,92.94%,91.92%,92.21%,and 98.00%,respectively,and the negative predictive values were 58.18%,29.27%,31.19%,66.38%,and 25.95%,respectively.The susceptibilities of Mycobacterium tuberculosis IgG detection,Mycobacterium tuberculosis culture and tuberculosis smear acid-fast staining for diagnosis of tuberculosis were significantly lower than that of IGRA(47.59%,54.82%,29.52% vs.86.14%,respectively,all P<0.05).The diagnostic sensitivities of Mycobacterium tuberculosis IgG and Mycobacterium tuberculosis culture for extra-pulmonary tuberculosis were significantly lower than that of IGRA(18.52%,33.33% vs.85.19%,P<0.05).The results of IGRA for Mycobacterium tuberculosis diagnosis in tuberculosis and non-tuberculosis groups compared with those of Mycobacterium tuberculosis IgG assay(χ^2 values were 0.004 and 1.685 respectively,all P>0.05)showed no statistical significant differences.The results of IGRA for Mycobacterium tuberculosis detection in tuberculosis and non-tuberculosis groups compared with those of Mycobacterium tuberculosis culture indicated that there were statistical significant differences(χ^2 values were 6.326 and 3.848,respectively,all P<0.05),showing that the performance of Mycobacterium tuberculosis IgG assay was weaker in the diagnosis of tuberculosis.Conclusion The IGRA detection for tuberculosis has high sensitivity and specificity,the positive predictive value and negative predictive value are significantly higher than those of Mycobacterium tuberculosis IgG detection,Mycobacterium tuberculosis culture and tuberculosis smear acid-fast staining,so that the IGRA detection for tuberculosis diagnosis has a good diagnostic value and is worthy for wide clinical application.