抗原诱发的γ干扰素测定在结核诊断中的应用

Application of antigen-induced interferon-gamma assay in diagnosis of tuberculosis

目的探讨结核分枝杆菌特异性抗原早期分泌抗原靶6000（ESAT-6）体外诱发的-γ干扰素反应在结核感染和结核病诊断中的价值。方法外周全血中加入ESAT-6抗原，诱导产生γ干扰素，以酶联免疫吸附法测定γ干扰素浓度，以增加的百分率为ESAT-6抗原诱发的γ干扰素反应值。对比结核密切接触者（60例）、痰培养证实的结核患者（46例）以及健康人（55例）及追踪调查儿童（68例）、青少年（52例）、老年（45例）的反应值。动态观察20例结核患者治疗过程中的反应值变化，比较HIV（＋）TB（＋）者（78例）和HIV（＋）TB（-）者（60例）的反应值。结果结核密切接触者与痰培养证实的结核患者的ESAT-6反应具有很高的敏感性。儿童与青少年的ESAT-6反应与临床诊断和预后具有很高的-致性。65％的结核患者在治疗过程中ESAT-6反应呈下降趋势。ESAT-6反应在HIV（＋）TB（＋）的诊断中敏感度为87．2％。结论体外ESAT-6诱发的γ干扰素测定对活动胜结核病尤其是儿童和青少年结核病的诊断有-定意义，也可用于鉴别HIV阳性者合并结核。

Objective To evaluate the value of early secreted antigen terget 6000 （ESAT-6）- induced interferon- gamma （IFN-γ） response in vitro in diagnosis of tuberculosis and Mycobacterium tuberculosis infections. Methods ESAT-6 was added into peripheral whole blood to induce IFN-γ, and concentration of IFN-γ was detected by ELISA. Comparied with saline control, the percentage of increase was regarded as the value of ESAT-6 induced IFN-γ response. ESAT-6-induced IFN-γ response was analysed in the following four aspects： comparison among the people in intimate contact with tuberculosis （60 cases）, the sputum culture-confirmed active tuberculosis patients （46 cases） and healthy people （55 cases）; comparison among children （68 cases）, adolescents （52 cases） and elder people （45 cases） by follow up; dynamically observation of 20 tuberculosis patients during long-term treatment; companison of HIV（＋） and TB（＋） people （78 cases） with HIV（＋ ） and TB（-） people （60 cases）. Results Of people in intimate contact with tuberculosis and active tuberculosis patients, ESAT-6 response had high sensitivity. ESAT-6 response in children and adolescents was completely consistent with the following clinical diagnosis and prognosis. ESAT- 6 response decreased during treatment duration in 65% tuberculosis patients. In HIV（＋） and TB（＋） cases, the sensitivity of tuberculosis diagnosis by ESAT-6 response was 87.2%. Conclusions In vitro IFN-γ response induced by ESAT-6 is helpful in diagnosis of tuberculosis, especially for children and adolescents. And it is also available for differential diagnosis of HIV（＋） patients with tuberculosis.