Division of Preventive Medicine, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA.
Clin Infect Dis. 2011 Aug 1;53(3):234-44. doi: 10.1093/cid/cir321.
The interferon-γ release assays (IGRAs) are increasingly being used as an alternative to the tuberculin skin test (TST). Although IGRAs may have better specificity and certain logistic advantages to the TST, their use may contribute to overtesting of low-prevalence populations if testing is not targeted. The objective of this study was to evaluate the accuracy of a risk factor questionnaire in predicting a positive test result for latent tuberculosis infection using the 3 commercially available diagnostics.
A cross-sectional comparison study was performed among recruits undergoing Army basic training at Fort Jackson, South Carolina, from April through June 2009. The tests performed included: (1) a risk factor questionnaire; (2) the QuantiFERON Gold In-Tube test (Cellestis Limited, Carnegie, Victoria, Australia); (3) the T-SPOT.TB test (Oxford Immunotec Limited, Abingdon, United Kingdom); and (4) the TST (Sanofi Pasteur Ltd., Toronto, Ontario, Canada). Prediction models used logistic regression to identify factors associated with positive test results. RFQ prediction models were developed independently for each test.
Use of a 4-variable model resulted in 79% sensitivity, 92% specificity, and a c statistic of 0.871 in predicting a positive TST result. Targeted testing using these risk factors would reduce testing by >90%. Models predicting IGRA outcomes had similar specificities as the skin test but had lower sensitivities and c statistics.
As with the TST, testing with IGRAs will result in false-positive results if the IGRAs are used in low-prevalence populations. Regardless of the test used, targeted testing is critical in reducing unnecessary testing and treatment.
NCT00804713.
干扰素-γ 释放试验（IGRAs）越来越多地被用作结核菌素皮肤试验（TST）的替代方法。虽然 IGRAs 可能比 TST 具有更高的特异性和某些优势，但如果不针对目标人群进行检测，它们的使用可能会导致低流行人群的过度检测。本研究的目的是评估风险因素问卷在预测潜伏性结核感染阳性检测结果方面的准确性，使用了 3 种市售诊断方法。
2009 年 4 月至 6 月，在南卡罗来纳州杰克逊堡接受陆军基础训练的新兵中进行了一项横断面比较研究。进行的检测包括：（1）风险因素问卷；（2）QuantiFERON Gold In-Tube 试验（Cellestis Limited，Carnegie，Victoria，Australia）；（3）T-SPOT.TB 试验（Oxford Immunotec Limited，Abingdon，United Kingdom）；和（4）TST（Sanofi Pasteur Ltd.，Toronto，Ontario，Canada）。预测模型使用逻辑回归来确定与阳性检测结果相关的因素。为每个测试独立开发了 RFQ 预测模型。
使用 4 变量模型预测 TST 阳性结果的敏感性为 79%，特异性为 92%，C 统计量为 0.871。使用这些危险因素进行靶向检测可将检测量减少>90%。预测 IGRA 结果的模型与皮肤试验具有相似的特异性，但敏感性和 C 统计量较低。
与 TST 一样，如果在低流行人群中使用 IGRAs，IGRAs 的检测结果也会出现假阳性。无论使用哪种检测方法，靶向检测对于减少不必要的检测和治疗都至关重要。
NCT00804713。
