Service of Infectious Diseases, Bellvitge University Hospital-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain; Department of Clinical Sciences, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain.
Service of Immunology, Bellvitge University Hospital-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
Clin Microbiol Infect. 2016 Dec;22(12):1007.e1-1007.e5. doi: 10.1016/j.cmi.2016.09.004. Epub 2016 Sep 16.
Previous reports have identified interleukin-2 (IL-2), quantified in the supernatants of QuantiFERON-TB Gold In-tube (QFT) after 72 h of incubation, as a potential biomarker for distinguishing between latent and active tuberculosis (TB). However, its validity has not been tested in an appropriate clinical cohort.
A multicentre study of 161 consecutive adult patients undergoing evaluation for active TB at eight TB Units in Spain. Interferon-γ (IFN-γ) and IL-2 were assessed in the supernatant of QFT after 16-24 h and 72 h of incubation. The accuracy of IL-2 for indicating latent TB infection (LTBI) was assessed by receiving operating characteristic curves. .
Twenty-eight participants were not infected, 43 had LTBI, 69 had TB, and 21 were not classifiable. Median (interquartile range) IL-2 concentrations after 72 h of incubation were 0.0 pg/mL (0.0-0.0) in uninfected individuals, 261.0 pg/mL (81.0-853.0) in LTBI individuals, 166.5 pg/mL (33.5-551.5) in patients with extrapulmonary TB, 95.0 pg/mL (26.0-283.0) in patients with smear-negative pulmonary TB, and 38.5 pg/mL (7.5-178.0) in patients with smear-positive pulmonary TB (p <0.0001). The area under the curve of the receiving operating characteristic curve (95% CI) of IL-2 after 72 h of incubation for the diagnosis of LTBI was 0.63 (0.53-0.74) when all TB cases were considered as a single group, ranging from 0.59 (0.47-0.71) to 0.72 (0.58-0.85) when only extrapulmonary and smear-positive pulmonary TB cases respectively were considered.
Quantification of IL-2 in the supernatant of QFT after a prolonged incubation is not useful to distinguish between LTBI and active disease in clinical practice.
先前的报告已经确定白细胞介素 2（IL-2），在经过 72 小时孵育后在 QuantiFERON-TB Gold In-tube（QFT）的上清液中进行定量，是区分潜伏性和活动性肺结核（TB）的潜在生物标志物。然而，其有效性尚未在适当的临床队列中进行测试。
对西班牙八个结核病单位的 161 名连续进行活动性结核病评估的成年患者进行了一项多中心研究。在 16-24 小时和 72 小时孵育后，评估 QFT 上清液中的干扰素-γ（IFN-γ）和 IL-2。通过接收操作特征曲线评估 IL-2 指示潜伏性 TB 感染（LTBI）的准确性。
28 名参与者未感染，43 名患有 LTBI，69 名患有结核病，21 名无法分类。未感染者 72 小时孵育后 IL-2 浓度的中位数（四分位数范围）为 0.0pg/mL（0.0-0.0），LTBI 个体为 261.0pg/mL（81.0-853.0），肺外 TB 患者为 166.5pg/mL（33.5-551.5），痰涂片阴性肺结核患者为 95.0pg/mL（26.0-283.0），痰涂片阳性肺结核患者为 38.5pg/mL（7.5-178.0）（p<0.0001）。当所有结核病病例均视为一个单一组时，IL-2 在 72 小时孵育后的接收操作特征曲线（95%CI）的曲线下面积（AUC）用于诊断 LTBI 的范围为 0.63（0.53-0.74），范围为 0.59（0.47-0.71）至 0.72（0.58-0.85），当仅考虑肺外和痰涂片阳性肺结核病例时分别为。
在临床实践中，长时间孵育后 QFT 上清液中 IL-2 的定量不能用于区分 LTBI 和活动性疾病。
