Department of Paediatrics, The University of Melbourne, Royal Children's Hospital Melbourne, Parkville, Victoria, Australia.
Int J Tuberc Lung Dis. 2011 Jun;15(6):767-9. doi: 10.5588/ijtld.10.0339.
The tuberculin skin test (TST) has been the established screening method for tuberculosis (TB) for over a century. Interferon-gamma release assays (IGRAs) using Mycobacterium tuberculosis-specific antigens are increasingly used as diagnostic tests for TB. Tuberculin comprises multiple antigens, including the antigens used in the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay. Exposure to these antigens by means of a TST may prime an immune response that leads to a false-positive result in a subsequent IGRA, limiting the validity of IGRAs in patients in whom these tests are performed sequentially. The current data on the influence of prior TST on IGRAs show inconsistent results.
Sixteen non-bacille Calmette-Guérin immunised medical students with no history of TB exposure and minimal risk of exposure to TB during the study period were tested simultaneously with a TST and QFT-GIT. The QFT-GIT assay was repeated 6 and 10 weeks later.
At baseline, all TST and QFT-GIT results were negative and remained negative 6 and 10 weeks after the TST.
These data show that negative QFT-GIT results are reproducible and suggest that a TST does not result in conversion of subsequent QFT-GIT assays in the absence of concomitant TB exposure. Therefore, a positive QFT-GIT should not be attributed to boosting induced by a previous TST.
结核菌素皮肤试验（TST）作为一种筛查结核病（TB）的方法，已经有一个多世纪的历史。使用结核分枝杆菌特异性抗原的干扰素-γ释放检测（IGRAs）作为 TB 的诊断检测方法越来越受到关注。结核菌素包含多种抗原，包括用于 QuantiFERON-TB Gold In-Tube（QFT-GIT）检测的抗原。通过 TST 暴露于这些抗原可能会引发免疫反应，导致随后的 IGRA 出现假阳性结果，从而限制了这些测试在这些测试连续进行的患者中的有效性。目前关于 TST 对 IGRAs 影响的数据显示结果不一致。
16 名未接种卡介苗的医学学生进行了 TST 和 QFT-GIT 同时检测，他们没有 TB 暴露史，在研究期间接触 TB 的风险很小。6 周和 10 周后重复 QFT-GIT 检测。
基线时，所有 TST 和 QFT-GIT 结果均为阴性，且在 TST 后 6 周和 10 周时仍为阴性。
这些数据表明，QFT-GIT 结果具有可重复性，且在没有同时接触 TB 的情况下，TST 不会导致随后的 QFT-GIT 检测结果转化。因此，阳性的 QFT-GIT 不应归因于之前 TST 引起的增强。
