B.M.B.Ch., Ed.M., Department of Paediatric Allergy and Infectious Diseases, Imperial College London, Norfolk Place, London W2 1NY, UK.
Am J Respir Crit Care Med. 2012 Aug 15;186(4):378-84. doi: 10.1164/rccm.201201-0026OC. Epub 2012 Jun 14.
Interferon-γ (IFN-γ) release assays are widely used to diagnose latent infection with Mycobacterium tuberculosis in adults, but their performance in children remains incompletely evaluated to date.
To investigate factors influencing results of IFN-γ release assays in children using a large European data set.
The Pediatric Tuberculosis Network European Trials group pooled and analyzed data from five sites across Europe comprising 1,128 children who were all investigated for latent tuberculosis infection by tuberculin skin test and at least one IFN-γ release assay. Multivariate analyses examined age, bacillus Calmette-Guérin (BCG) vaccination status, and sex as predictor variables of results. Subgroup analyses included children who were household contacts.
A total of 1,093 children had a QuantiFERON-TB Gold In-Tube assay and 382 had a T-SPOT.TB IFN-γ release assay. Age was positively correlated with a positive blood result (QuantiFERON-TB Gold In-Tube: odds ratio [OR], 1.08 per year increasing age [P < 0.0001]; T-SPOT.TB: OR, 1.14 per year increasing age [P < 0.001]). A positive QuantiFERON-TB Gold In-Tube result was shown by 5.5% of children with a tuberculin skin test result less than 5 mm, by 14.8% if less than 10 mm, and by 20.2% if less than 15 mm. Prior BCG vaccination was associated with a negative IFN-γ release assay result (QuantiFERON-TB Gold In-Tube: OR, 0.41 [P < 0.001]; T-SPOT.TB: OR, 0.41 [P < 0.001]). Young age was a predictor of indeterminate IFN-γ release assay results, but indeterminate rates were low (3.6% in children < 5 yr, 1% in children > 5 yr).
Our data show that BCG vaccination may be effective in protecting children against Mycobacterium tuberculosis infection. To restrict use of IFN-γ release assays to children with positive skin tests risks underestimating latent infection.
干扰素-γ（IFN-γ）释放试验被广泛用于诊断成人潜伏性结核分枝杆菌感染，但迄今为止，其在儿童中的应用效果尚未得到充分评估。
利用欧洲的大型数据集，研究影响儿童干扰素-γ释放试验结果的因素。
儿科结核网络欧洲试验组汇集并分析了来自欧洲 5 个地点的 1128 名儿童的数据，这些儿童均接受了结核菌素皮肤试验和至少一种 IFN-γ释放试验来调查潜伏性结核感染。多变量分析将年龄、卡介苗（BCG）接种状态和性别作为结果的预测变量。亚组分析包括了家庭接触者的儿童。
共有 1093 名儿童接受了 QuantiFERON-TB Gold In-Tube 检测，382 名儿童接受了 T-SPOT.TB IFN-γ 释放检测。年龄与血液检测阳性结果呈正相关（QuantiFERON-TB Gold In-Tube：每增加 1 岁，比值比[OR]为 1.08[P<0.0001]；T-SPOT.TB：OR 为 1.14/年[P<0.001]）。结核菌素皮肤试验结果<5mm 的儿童中有 5.5%出现 QuantiFERON-TB Gold In-Tube 阳性结果，结果<10mm 的儿童中有 14.8%，结果<15mm 的儿童中有 20.2%。BCG 接种前与 IFN-γ释放试验阴性结果相关（QuantiFERON-TB Gold In-Tube：OR 为 0.41[P<0.001]；T-SPOT.TB：OR 为 0.41[P<0.001]）。年龄小是 IFN-γ释放试验不确定结果的预测因素，但不确定率较低（<5 岁儿童为 3.6%，>5 岁儿童为 1%）。
我们的数据表明，BCG 接种可能对儿童预防结核分枝杆菌感染有效。如果仅将 IFN-γ释放试验用于皮肤试验阳性的儿童，可能会低估潜伏性感染。
