Detjen A K, Keil T, Roll S, Hauer B, Mauch H, Wahn U, Magdorf K
Department of Pediatric Pneumology and Immunology, Charite University Medical Center, Berlin, Germany.
Clin Infect Dis. 2007 Aug 1;45(3):322-8. doi: 10.1086/519266. Epub 2007 Jun 15.
Diagnosis of childhood tuberculosis (TB) is challenging. The widely used tuberculin skin test (TST) may produce -positive results because of cross-reactivity with nontuberculous mycobacteria or bacille Calmette-Guerin vaccination, resulting in unnecessary treatment. Two recently developed interferon- gamma release assays (IGRAs) show good diagnostic accuracy for active TB in adults; pediatric data are limited, particularly in areas with a low incidence of TB. We assessed the diagnostic accuracy of IGRAs for TB in children in an area with a low incidence of TB.
In a hospital-based study, the diagnostic accuracy of the TST and 2 IGRAs (T SPOT-TB [T-SPOT; Oxford Immunotec] and QuantiFERON-TB Gold In-Tube [QFT-IT; Cellestis]) were assessed in a cohort of 73 children (median age, 39 months); 28 children with bacteriologically confirmed TB were compared with children without TB (23 with bacteriologically confirmed nontuberculous mycobacterial lymphadenitis and 22 with other nonmycobacterial respiratory tract infections).
The specificity for TB of QFT-IT was 100% (95% confidence interval [CI], 91%-100%), and the specificity of T-SPOT was 98% (95% CI, 87%-100%), both of which were considerably higher than the specificity of TST (58%; 95% CI, 42%-73%). The specificity of the TST was 10.5% (95% CI, 1%-33%) in children with nontuberculous mycobacterial lymphadenitis and was 100% (95% CI, 83%-100%) in children with other nonmycobacterial respiratory tract infections. The sensitivity of both QFT-IT and T-SPOT was 93% (95% CI, 77%-99%), and the sensitivity of the TST was 100% (95% CI, 88%-100%). Agreement between the IGRAs was 95.6% ( kappa =0.91); 6.8% of the IGRAs showed indeterminate results.
Both IGRAs showed high diagnostic value in bacteriologically confirmed childhood TB. Their advantage in this study, when performed in addition to the TST, was the ability to distinguish -positive TST results caused by nontuberculous mycobacterial disease, thereby reducing overdiagnosis of TB and guiding clinical management.
儿童结核病的诊断具有挑战性。广泛使用的结核菌素皮肤试验（TST）可能因与非结核分枝杆菌交叉反应或卡介苗接种而产生阳性结果，导致不必要的治疗。最近开发的两种干扰素-γ释放试验（IGRAs）对成人活动性结核病显示出良好的诊断准确性；儿科数据有限，尤其是在结核病发病率低的地区。我们评估了IGRAs在结核病低发地区儿童结核病诊断中的准确性。
在一项基于医院的研究中，对73名儿童（中位年龄39个月）队列评估了TST和两种IGRAs（T SPOT-TB [T-SPOT；牛津免疫技术公司]和QuantiFERON-TB Gold In-Tube [QFT-IT；Cellestis]）的诊断准确性；将28例细菌学确诊的结核病患儿与无结核病患儿（23例细菌学确诊的非结核分枝杆菌淋巴结炎患儿和22例其他非分枝杆菌呼吸道感染患儿）进行比较。
QFT-IT对结核病的特异性为100%（95%置信区间[CI]，91%-100%），T-SPOT的特异性为98%（95%CI，87%-100%），两者均显著高于TST的特异性（58%；95%CI，42%-73%）。TST在非结核分枝杆菌淋巴结炎患儿中的特异性为10.5%（95%CI，1%-33%），在其他非分枝杆菌呼吸道感染患儿中的特异性为100%（95%CI，83%-100%）。QFT-IT和T-SPOT的敏感性均为93%（95%CI，77%-99%），TST的敏感性为100%（95%CI，88%-100%）。IGRAs之间的一致性为95.6%（kappa=0.91）；6.8%的IGRAs结果不确定。
两种IGRAs在细菌学确诊的儿童结核病中均显示出较高的诊断价值。在本研究中，它们除TST外的优势在于能够区分由非结核分枝杆菌疾病引起的TST阳性结果，从而减少结核病的过度诊断并指导临床管理。
