Liu F, Du F-J, Jia H-Y, Pan L-P, Zhang X, Xing A-Y, Du B-P, Sun Q, Nie L-H, Li H, Liu R-M, Ma Y, Zhang Z-D
Beijing Key Laboratory for Drug-Resistant Tuberculosis Research, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China.
Tuberculosis Department, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China.
Int J Tuberc Lung Dis. 2014 Dec;18(12):1496-501. doi: 10.5588/ijtld.14.0233.
To examine the usefulness of an interferon-gamma release assay (IGRA) for the diagnosis of smear-negative tuberculosis (TB) in China.
A total of 624 patients with presumed pulmonary TB were enrolled prospectively and categorised as smear-negative TB, smear-positive TB or no TB. All patients were tested using T-SPOT.TB.
Both the smear-negative and smear-positive TB groups had significantly more spot-forming cells (SFCs) than the no TB group (all P < 0.001), while the smear-negative group had fewer SFCs than the smear-positive TB group (P < 0.001). The specificity of T-SPOT.TB was 60.4% (95%CI 53.4-67.1). The sensitivities of T-SPOT.TB in the smear-negative and smear-positive TB groups were respectively 81.4% (95%CI 75.7-86.0) and 93.2% (95%CI 87.6-96.4). The sensitivity in the smear-negative TB group was much lower than that in the smear-positive TB (P < 0.05).
The sensitivity of T-SPOT.TB was lower due the paucibacillary nature of the samples, and the specificity was lower due to the high prevalence of latent tuberculous infection in the smear-negative TB patients. The T-SPOT.TB test should only be used as a supplementary test and not as a single test to rule in or rule out smear-negative TB.
探讨γ-干扰素释放试验（IGRA）在中国诊断涂片阴性肺结核（TB）中的应用价值。
前瞻性纳入624例疑似肺结核患者，分为涂片阴性肺结核组、涂片阳性肺结核组和非肺结核组。所有患者均采用T-SPOT.TB检测。
涂片阴性肺结核组和涂片阳性肺结核组的斑点形成细胞（SFC）均显著多于非肺结核组（均P<0.001），而涂片阴性肺结核组的SFC少于涂片阳性肺结核组（P<0.001）。T-SPOT.TB的特异性为60.4%（95%CI 53.4-67.1）。T-SPOT.TB在涂片阴性肺结核组和涂片阳性肺结核组中的敏感性分别为81.4%（95%CI 75.7-86.0）和93.2%（95%CI 87.6-96.4）。涂片阴性肺结核组的敏感性远低于涂片阳性肺结核组（P<0.05）。
由于样本中细菌数量少，T-SPOT.TB的敏感性较低；由于涂片阴性肺结核患者中潜伏结核感染的高患病率，其特异性较低。T-SPOT.TB检测仅应用作补充检测，而不能作为诊断或排除涂片阴性肺结核的单一检测方法。
