Lee Y-M, Park K-H, Kim S-M, Park S J, Lee S-O, Choi S-H, Kim Y S, Woo J H, Kim S-H
Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul, 138-736, Republic of Korea.
Infection. 2013 Dec;41(6):1089-95. doi: 10.1007/s15010-013-0478-z. Epub 2013 Aug 14.
T-SPOT.TB, a recently developed T cell-based assay, has shown promise in diagnosing extrapulmonary tuberculosis (EPTB). However, a limited number of reports have compared the risk factors for false-negative results of tuberculin skin tests (TSTs) and T-SPOT.TB assays in patients with EPTB. We, thus, conducted a prospective, blinded, observational study to evaluate the risk factors for false-negative T-SPOT.TB and TST results in patients with EPTB.
Between April 2008 and November 2011, all adult patients with suspected EPTB were prospectively enrolled at Asan Medical Center, Seoul, South Korea (an intermediate TB-burden country). Only patients with confirmed and probable EPTB who underwent TST and T-SPOT.TB were included in the final analysis.
Of the 324 patients who underwent both TST and T-SPOT.TB testing, 128 patients with 96 (75 %) culture- or polymerase chain reaction (PCR)-confirmed and 32 (25 %) probable EPTB were finally analyzed. T-SPOT.TB assays were less likely to yield false-negative results than TSTs [17 % (22/128) vs. 54 % (69/128), p < 0.001]. In a multivariate analysis, miliary TB was associated with false-negative TSTs [odds ratio (OR) = 5.3; 95 % confidence interval (CI) 1.7-16.1], while immunosuppression showed a trend toward false-negative TSTs (OR = 2.5; 95 % CI 0.9-6.8). Conversely, lymph node TB (OR = 0.2; 95 % CI 0.1-0.5) and skeletal TB (OR = 0.2; 95 % CI 0.1-0.5) were associated with true-positive TST results. The only risk factor for false-negative T-SPOT.TB results was TB meningitis (OR = 2.6; 95 % CI 1.0-6.6).
Our findings suggest that T-SPOT.TB has a better sensitivity to diagnose EPTB than TST, especially in patients with immunosuppression or miliary TB.
T-SPOT.TB是一种最近开发的基于T细胞的检测方法，在诊断肺外结核（EPTB）方面显示出前景。然而，仅有有限数量的报告比较了EPTB患者结核菌素皮肤试验（TST）和T-SPOT.TB检测出现假阴性结果的风险因素。因此，我们进行了一项前瞻性、盲法观察性研究，以评估EPTB患者T-SPOT.TB和TST出现假阴性结果的风险因素。
在2008年4月至2011年11月期间，韩国首尔峨山医学中心（一个结核病负担中等的国家）前瞻性纳入了所有疑似EPTB的成年患者。最终分析仅纳入接受了TST和T-SPOT.TB检测且确诊或可能患有EPTB的患者。
在324例同时接受TST和T-SPOT.TB检测的患者中，最终分析了128例患者，其中96例（75%）经培养或聚合酶链反应（PCR）确诊，32例（25%）可能患有EPTB。与TST相比，T-SPOT.TB检测产生假阴性结果的可能性更小[17%（22/128）对54%（69/128），p<0.001]。在多变量分析中，粟粒性结核与TST假阴性相关[比值比（OR）=5.3；95%置信区间（CI）1.7-16.1]，而免疫抑制显示出TST假阴性的趋势（OR=2.5；95%CI 0.9-6.8）。相反，淋巴结结核（OR=0.2；95%CI 0.1-0.5）和骨骼结核（OR=0.2；95%CI 0.1-0.5）与TST真阳性结果相关。T-SPOT.TB假阴性结果的唯一风险因素是结核性脑膜炎（OR=2.6；95%CI 1.0-6.6）。
我们的研究结果表明，T-SPOT.TB在诊断EPTB方面比TST具有更好的敏感性，尤其是在免疫抑制或粟粒性结核患者中。
