Department of Pediatrics (CDRCP), Division of Endocrinology, Oregon Health & Science University, Portland, OR 97219, USA.
J Inherit Metab Dis. 2010 Oct;33(Suppl 2):S225-33. doi: 10.1007/s10545-010-9062-1. Epub 2010 Mar 2.
It is the purpose of this article to briefly review the initial development and subsequent evolution of newborn screening programs to detect infants with congenital hypothyroidism (CH) and then to provide an update of the advantages and disadvantages of the main test strategies. Pilot programs began screening newborn populations in North America in the mid-1970s using either primary thyroxine (T4)-follow-up thyroid stimulating hormone (TSH) or primary TSH testing. Many programs in the United States and around the world continue to prefer a primary T4-follow-up TSH test strategy. This approach has the advantage of detecting infants with primary CH, as well as cases of hypopituitary hypothyroidism, by follow-up of infants with a T4 below an absolute cutoff or with a persistently low T4 level, necessitating a higher recall rate. With increasing assay sensitivity and specificity, several programs in the United States and worldwide have elected to switch to a primary TSH test strategy. This test strategy has the advantage of detecting primary CH and subclinical hypothyroidism and at a lower recall rate. Programs considering switching to a primary TSH test strategy need to develop age-related TSH cutoffs to maintain an acceptable recall rate. Both test strategies have the potential to detect infants with CH characterized by "delayed TSH rise," but only if they collect a routine or discretionary second specimen, now recommended in low-birth-weight and acutely ill infants. Lastly, a lower TSH cutoff appears to be one of the explanations for the recently described increased incidence of CH.
本文旨在简要回顾先天性甲状腺功能减退症（CH）新生儿筛查项目的最初发展和后续演变，然后介绍主要检测策略的优缺点。20 世纪 70 年代中期，北美一些试点项目开始使用基础甲状腺素（T4）-促甲状腺激素（TSH）或基础 TSH 检测对新生儿人群进行筛查。美国和世界各地的许多项目仍然倾向于采用基础 T4-后续 TSH 测试策略。这种方法的优点是可以通过对 T4 低于绝对截止值或持续低 T4 水平的婴儿进行随访，检测出原发性 CH 婴儿以及垂体性甲状腺功能减退症病例，因此需要更高的召回率。随着检测方法敏感性和特异性的提高，美国和世界上的一些项目已选择转为基础 TSH 测试策略。这种测试策略的优点是可以检测出原发性 CH 和亚临床甲状腺功能减退症，且召回率较低。考虑转为基础 TSH 测试策略的项目需要制定与年龄相关的 TSH 截止值，以保持可接受的召回率。这两种检测策略都有可能检测出表现为“TSH 延迟升高”的 CH 婴儿，但前提是他们采集常规或选择性的第二份样本，目前建议对低出生体重和急性病婴儿进行采集。最后，较低的 TSH 截止值似乎是最近描述的 CH 发病率增加的原因之一。
