Walfish P G
Lancet. 1976 Jun 5;1(7971):1208-10. doi: 10.1016/s0140-6736(76)92159-0.
Three thyroid-function detection methods were evaluated concomitantly for possible application as routine screening tests for the early diagnosis of neonatal hypothyroidism. Dried capillary-blood thyroxine (T4) was measured on eluted filter-paper discs for 9734 3-5-day old neonates. Serum T4 and thyroid-stimulating hormone (T.S.H.) assays from cord blood were studied as alternative screening tests on 4911 and 3733 infants, respectively. To avoid false-negative results, neonatal blood-T4 and cord serum-T4 screening methods were followed up for the lower 10th and 6th percentile, respectively. This resulted in a false-positive recall incidence greater than 92% owing to various additional factors which also influence T4 levels: thyroxine-binding-globulin deficiency, prematurity, and maternal drug ingestion. In marked contrast, cord T.S.H. as an initial screening test had a higher specificity and sensitivity for the diagnosis of primary hypothyroidism with the two affected cases, having values greater than 70 muU/ml (with only 0-24% of the screened population having values greater than 50 muU/ml). In order to avoid the impracticably high recallrate and false-positive incidence resulting from an initial T4 screening test, and to reduce the estimated follow-up recall to less than 0-2% of the screened infant population, it is recommended that infants with low T4 be selected for a supplementary T.S.H. screening test.
同时评估了三种甲状腺功能检测方法，以确定其作为新生儿甲状腺功能减退症早期诊断常规筛查试验的可能性。对9734名3 - 5日龄新生儿的洗脱滤纸圆盘上的干毛细血管血甲状腺素（T4）进行了测量。分别对4911名和3733名婴儿进行了脐血血清T4和促甲状腺激素（TSH）检测，作为替代筛查试验。为避免假阴性结果，分别对新生儿血T4和脐血血清T4筛查方法在第10百分位数和第6百分位数下限进行随访。由于甲状腺素结合球蛋白缺乏、早产和母亲药物摄入等多种也影响T4水平的额外因素，导致假阳性召回率大于92%。与之形成鲜明对比的是，脐血TSH作为初始筛查试验，对原发性甲状腺功能减退症的诊断具有更高的特异性和敏感性，两例受影响病例的值大于70 μU/ml（筛查人群中只有0 - 24%的值大于50 μU/ml）。为避免因初始T4筛查试验导致的高得离谱的召回率和假阳性发生率，并将估计的随访召回率降低至筛查婴儿人群的0 - 2%以下，建议对T4低的婴儿进行补充TSH筛查试验。
