γ-干扰素释放试验在肺外结核诊断中的应用与评价

Evaluation of interferon-gamma release technique in extra-pulmonary tuberculosis detection

目的探讨γ-干扰素释放试验(T细胞斑点试验)在肺外结核诊断中的使用效能。方法通过对265例入组的肺外结核疑似患者进行T细胞斑点试验检测,分析该技术在肺外结核中的诊断效能和影响该检测结果的风险因素。结果 265例患者中,确诊肺外结核147例、可疑肺外结核32例、排除结核感染86例。在去除可疑样本之后,T细胞斑点试验灵敏度和特异性分别为81%和53%。其中,T细胞斑点试验对淋巴结核与结核性腹膜炎检测灵敏度最高,均为88%;结核性胸膜炎检测的灵敏度最低,为75%;T细胞斑点试验对淋巴结核检测的特异性最高,为67%;而肠结核检测的特异性最低,仅为44%。在免疫功能低下人群中,其灵敏度较免疫功能正常人群显著降低(P<0.05)。此外,年龄(≥65岁)对T细胞斑点试验灵敏度及对阳性预测值和阴性预测值的影响具有统计学意义(P<0.05)。结论 T细胞斑点试验能够作为疑似肺外结核鉴别的辅助诊断工具,具有较高的灵敏度,但在不同感染部位的检测效能不同。T细胞斑点试验检测结果受到患者免疫功能状态与年龄的影响,因此在进行该项检测之前有必要对患者免疫状态等相关因素进行评估。

Objective To evaluate the clinic presentation of interferon-gamma release method（ T cell spot test） in extra-pulmonary tuberculosis（ E-TB） diagnosis. Methods Totally 265 suspect E-TB patients were included in the study. The clinic practice and risk factors were analyzed. Results Among the 265 cases,there were 147 were diagnosed as E-TB infection that confirmed by bacteriology or histology. E-TB was excluded in 86 patients,and the rest of 32 cases still cannot be diagnosed. After the suspicious cases removed,the sensitivity and specificity of T cell spot test assay were 81% and 53%. Among them,the sensitivity in crewels and tuberculous peritonitis detection was higher than others（ both 88%）; in tuberculous pleuritis detection was75%. The specificity in crewels was higher than others（ 67%）; in tuberculosis of intestine detection was only44%.The sensitivity in immunecompromised group were decreased significantly（ P〈0. 05）,besides,the sensitivity was also affected by age factor（ ≥ 65 y,P〈0.05）. There was statistically significant in potitive predictive value and negative predictive value（ P〈0.05）. Conclusions T cell spot test TB is an effective tool for extra-pulmonary tuberculosis diagnosis with high sensitivity. Besides,the results can be affected by the condition of patients＇ immunologic function and age factor（ ≥65y）. So,it is necessary to test the the immune status of the patient before making the T cell spot test detection,and age factor should also be considered.