Jeon You La, Kim Min-Jeong, Lee Woo-In, Kim Myeong Hee, Kang So Young
Department of Laboratory Medicine, School of Medicine, Kyung Hee University and Kyung Hee University Hospital at Gangdong, South Korea.
Department of Consumer Economics, Sookmyung Women's University, Seoul, South Korea.
Lab Med. 2017 Aug 1;48(3):214-219. doi: 10.1093/labmed/lmx022.
We derived a new equation to include interferon-γ (IFN-γ) levels in the QuantiFERON-Gold In-Tube (QFT-GIT) assay to discriminate active tuberculosis (ATB) infection from latent TB, and compared the diagnostic performance of the QFT-GIT assay and the new equation.
From January 2013 through May 2015, we retrospectively enrolled 159 and 408 patients with and without ATB, respectively, in this study. Discriminant analysis was performed to derive an equation to distinguish the ATB group from the non-ATB group.
The sensitivity and specificity of the QFT-GIT assay for diagnosing ATB were 90.6% and 63.0%, respectively. The positive and negative predictive values of the QFT-GIT assay were 48.8% and 94.5%, respectively. When the optimal cutoff for the new equation [Z = (0.031 × Nil) + (0.007 × TBAg) - 0.978] was set to -0.435, the sensitivity and specificity were 84.3% and 69.1% (positive predictive value, 51.5%; negative predictive value, 91.9%), respectively.
The QFT-GIT assay and the equation derived from each IFN-γ could not discriminate ATB from latent TB without considering other cytokines involved in immunity against TB.
我们推导了一个新方程，将定量γ-干扰素（IFN-γ）水平纳入管内QuantiFERON-金标检测法（QFT-GIT）中，以区分活动性结核病（ATB）感染与潜伏性结核，并比较了QFT-GIT检测法和新方程的诊断性能。
从2013年1月至2015年5月，我们分别回顾性纳入了159例患有ATB的患者和408例未患ATB的患者。进行判别分析以推导一个区分ATB组和非ATB组的方程。
QFT-GIT检测法诊断ATB的敏感性和特异性分别为90.6%和63.0%。QFT-GIT检测法的阳性预测值和阴性预测值分别为48.8%和94.5%。当新方程[Z = (0.031 × Nil) + (0.007 × TBAg) - 0.978]的最佳截断值设定为-0.435时，敏感性和特异性分别为84.3%和69.1%（阳性预测值为51.5%；阴性预测值为91.9%）。
在不考虑其他参与抗结核免疫的细胞因子的情况下，QFT-GIT检测法和由各IFN-γ推导的方程无法区分ATB和潜伏性结核。
