Streeton J A, Desem N, Jones S L
Mercy Private Hospital Consulting Suites, East Melbourne, VIC, Australia.
Int J Tuberc Lung Dis. 1998 Jun;2(6):443-50.
Victoria, Australia.
To determine the sensitivity and specificity of a gamma interferon (IFN-gamma) blood test for tuberculosis infection.
Heparinised blood samples from 952 volunteers were analysed using the QuantiFERON-TB blood test. The levels of IFN-gamma in whole blood aliquots stimulated in vitro with human, avian or bovine purified protein derivative (PPD), or phytohaemagglutinin (PHA), were compared to tuberculin reactivity and clinical presentation.
IFN-gamma (IU/ml) responses were expressed as % PPD/PHA response ratios. The proportion of responders detected by both the IFN-gamma assay and tuberculin skin test (TST) was not significantly different when the % human PPD response ratio was 15%. Using this threshold, the specificity of the IFN-gamma assay was 98% (407/417 individuals with no known exposure to tuberculosis were negative) and sensitivity was 90% (163/182 untreated TST reactors were positive). The test detected positive responses in 83% (10/12) of individuals with proven active disease, 59% (24/41) of those previously treated, 80% (134/168) of those with untreated inactive disease, and 43% (55/128) of those exposed but TST-negative.
The measurement of IFN-gamma released from PPD-stimulated blood lymphocytes is a specific, sensitive and rapid method of detecting Mycobacterium tuberculosis infection. The IFN-gamma assay may be a useful and practical tool for the early diagnosis of tuberculosis infection, especially in immunocompetent individuals.
澳大利亚维多利亚州。
确定γ干扰素（IFN-γ）血液检测对结核感染的敏感性和特异性。
采用结核菌素全血检测法对952名志愿者的肝素化血样进行分析。将用人、禽或牛纯化蛋白衍生物（PPD）或植物血凝素（PHA）体外刺激的全血样本中的IFN-γ水平与结核菌素反应性及临床表现进行比较。
IFN-γ（IU/ml）反应以PPD/PHA反应百分比表示。当人PPD反应百分比为15%时，IFN-γ检测和结核菌素皮肤试验（TST）检测出的反应者比例无显著差异。以此为阈值，IFN-γ检测的特异性为98%（417名无已知结核接触史的个体中有407名检测为阴性），敏感性为90%（182名未经治疗的TST反应者中有163名检测为阳性）。该检测在83%（10/12）的确诊活动性疾病个体、59%（24/41）的既往治疗个体、80%（134/168）的未经治疗的非活动性疾病个体以及43%（55/128）的接触过结核但TST阴性个体中检测到阳性反应。
检测PPD刺激的血液淋巴细胞释放的IFN-γ是一种检测结核分枝杆菌感染的特异性、敏感性和快速的方法。IFN-γ检测可能是早期诊断结核感染的一种有用且实用的工具，尤其是在免疫功能正常的个体中。
