Lee Hyun Woo, Lee Yeon Joo, Kim Se Joong, Park Jong Sun, Cho Young-Jae, Yoon Ho Il, Lee Choon-Taek, Lee Jae-Ho
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
Korean J Intern Med. 2017 May;32(3):486-496. doi: 10.3904/kjim.2015.344. Epub 2017 Jan 24.
BACKGROUND/AIMS: The tuberculin skin test (TST) and interferon γ release assay are currently used as diagnostic tools to detect latent tuberculosis (TB) infection; however, there are inconsistencies about the degree of agreement between the tests. We aimed to evaluate the concordance rate between the two tests in household contacts of a country with intermediate TB burden, where most people were vaccinated.
We recruited household contacts who spent > 8 hours daily with patients with microbiologically confirmed active pulmonary TB, and received both TST and T-SPOT.TB (Oxford Immunotec) simultaneously. The degree of agreement was analysed according to TST cutoff and Bacille Calmette-Guerin (BCG) vaccination status. Relevant factors were analysed to establish the association with TST or T-SPOT.TB.
Among 298 household contacts, 122 (40.9%) were spouses, and 250 (83.9%) had received BCG vaccination. In the contact sources, 117 (39.3%) showed a positive result for acid-fast bacillus (AFB) sputum smear and 109 (36.6%) had cavities. The highest agreement rate of 69.5% and κ value of 0.378 were found with a 10 mm cutoff. Spouse, time interval from TB diagnosis to test, and AFB sputum smear positivity were significantly associated with a positive result for T-SPOT.TB. Sex, BCG vaccination, and cavity on chest computed tomography were related to TST positivity.
The present study suggested it was not possible for TST and T-SPOT.TB to replace each other because of considerable discrepancy between the two tests in household contacts in a country with intermediate TB prevalence.
背景/目的：结核菌素皮肤试验（TST）和干扰素γ释放试验目前用作检测潜伏性结核感染的诊断工具；然而，这两种试验之间的一致程度存在不一致之处。我们旨在评估在一个结核病负担中等且大多数人接种过疫苗的国家中，家庭接触者中这两种试验之间的一致率。
我们招募了每天与微生物学确诊的活动性肺结核患者共处超过8小时的家庭接触者，并同时进行TST和T-SPOT.TB（牛津免疫技术公司）检测。根据TST临界值和卡介苗（BCG）接种状况分析一致程度。分析相关因素以确定与TST或T-SPOT.TB的关联。
在298名家庭接触者中，122名（40.9%）是配偶，250名（83.9%）接种过卡介苗。在接触源中，117名（39.3%）痰涂片抗酸杆菌（AFB）检测呈阳性，109名（36.6%）有空洞。临界值为10 mm时，一致率最高，为69.5%，κ值为0.378。配偶、从结核病诊断到检测的时间间隔以及痰涂片AFB阳性与T-SPOT.TB阳性结果显著相关。性别、卡介苗接种以及胸部计算机断层扫描显示的空洞与TST阳性相关。
本研究表明，在一个结核病患病率中等的国家，由于家庭接触者中这两种试验存在相当大的差异，TST和T-SPOT.TB不可能相互替代。
