Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India.
Department of Endocrinology, All India Institute of Medical Sciences, New Delhi, India.
Eur J Clin Nutr. 2014 Jan;68(1):38-42. doi: 10.1038/ejcn.2013.216. Epub 2013 Oct 30.
BACKGROUND/OBJECTIVES: Data on performance of QuantiFERON-TB Gold In-Tube test (QFT) and tuberculin skin test (TST) in children with active tuberculosis from high burden countries in the context of micronutrient deficiency are scarce. The objective of this study was to evaluate the effect of micronutrient deficiency on the performance of TST and QFT in children with intrathoracic tuberculosis.
SUBJECTS/METHODS: Children with probable intrathoracic tuberculosis underwent TST, QFT, gastric lavages and induced sputum examination for AFB (Acid-Fast Bacilli) smear and culture. Zinc, copper, ferritin and vitamin D were measured on stored serum samples. The study used cross-sectional data at initiation of anti-tubercular therapy.
Three hundred and sixty-two children (median age 115.5 months (interquartile range: 73, 144), 200 (55.3%) girls) were enrolled in the study. Microbiological confirmation of tuberculosis could be obtained in 128 patients. TST and QFT were positive in 337 (93%) and 297 (82%) children, respectively. Performance of both the tests was unaffected by weight-for-age and height-for-age 'z-scores' or by serum copper levels. TST was not affected by serum zinc and ferritin levels. Children with negative QFT results had lower mean serum zinc level (P=0.01) and higher ferritin levels (P=0.007) as compared to those with positive test. Higher proportion of children with positive TST were vitamin D deficient/insufficient (P=0.003).
Micronutrient status, especially serum levels of zinc, may influence the performance of QFT in children with intrathoracic tuberculosis. Considering the high prevalence of zinc deficiency in developing countries, QFT should be used cautiously for diagnosing tuberculosis.
背景/目的：来自高负担国家的活动性肺结核患儿的 QuantiFERON-TB Gold In-Tube 试验（QFT）和结核菌素皮肤试验（TST）的数据在微量元素缺乏的情况下很少。本研究的目的是评估微量元素缺乏对儿童胸腔内结核患者 TST 和 QFT 表现的影响。
受试者/方法：疑似患有胸腔内结核的儿童接受 TST、QFT、胃液和诱导痰检查，以进行抗酸杆菌（AFB）涂片和培养。在开始抗结核治疗时，对储存的血清样本进行锌、铜、铁蛋白和维生素 D 测量。本研究使用了横断面数据。
362 名儿童（中位年龄 115.5 个月（四分位距：73，144），200 名（55.3%）女孩）入组本研究。128 名患者获得了结核病的微生物学证实。TST 和 QFT 在 337 名（93%）和 297 名（82%）儿童中分别呈阳性。这两项检测的性能均不受体重年龄和身高年龄“Z 评分”或血清铜水平的影响。TST 不受血清锌和铁蛋白水平的影响。QFT 结果阴性的儿童的平均血清锌水平较低（P=0.01），铁蛋白水平较高（P=0.007），而 QFT 结果阳性的儿童则相反。更多的 TST 阳性儿童存在维生素 D 缺乏/不足（P=0.003）。
微量元素状况，特别是血清锌水平，可能会影响胸腔内结核患儿 QFT 的表现。考虑到发展中国家锌缺乏症的高患病率，QFT 用于诊断结核病时应谨慎使用。
