新生儿甲状腺功能减退症筛查中的年龄依赖性临界值。

Age-dependent cutoff values in screening newborns for hypothyroidism.

作者信息

Lott John A, Sardovia-Iyer Marlinda, Speakman Karen S, Lee Kevin K

机构信息

The Ohio Department of Health Newborn Screening Laboratory, Columbus, OH 43201, USA.

出版信息

Clin Biochem. 2004 Sep;37(9):791-7. doi: 10.1016/j.clinbiochem.2004.05.019.

DOI:10.1016/j.clinbiochem.2004.05.019

PMID:15329318

Abstract

OBJECTIVES

We wanted to develop age-related reference (cutoff) values and an algorithm to identify babies at low, moderate, and high risk for hypothyroidism of any cause. We used thyroid-stimulating hormone (TSH) as the primary tool, and thyroxine (T4) as part of a confirmatory test. Our data permitted us to estimate cutoff values for newborns at <24 h, 24 to 47 h, 48 to 71 h, 72 to 95 h, and > or =96 h after birth.

METHODS

We used a time-resolved fluoroimmunoassay method for TSH and T4 with the AutoDELPHIA instrument (Perkin-Elmer Life Sciences, Turku, Finland). TESTING ALGORITHM: We developed a conservative algorithm for TSH and T4 testing. In the initial screening, we used a > or =20 microIU/ml cutoff for TSH to identify those babies of any age who required confirmatory testing on a repunched filter paper blood specimen.

RESULTS

In 161,244 newborns tested during 2002, we found 8,035 babies with TSH values > or =20 microIU/ml. Graphs of the values for TSH vs. age in hours revealed the possibility of using more than one cutoff value. The general finding was that the cutoff values decreased with increasing age of the newborn.

CONCLUSIONS

Based on our findings, we conclude that testing babies who are <24 h old is not recommended and should only be performed if no other specimen is available. A high TSH in babies <24 h old is unreliable for screening newborns for hypothyroidism. We routinely stipulate that the infant be at least 48 h old for TSH and T4 testing. If not, the cutoff value must be set to a higher value to prevent an excessive number of false-positive results; however, this increases the chance of missing a truly hypothyroid baby. We designated newborns as being at "low" (LR), "moderate" (MR), or at "high" risk (HR) for hypothyroidism. The TSH test continues to be a screening test; and follow-up quantitative testing and clinical evaluation are needed for all babies identified as being at MR or HR for hypothyroidism.

SETTING

Newborn Screening Laboratory of the Ohio Department of Health, Columbus, Ohio.

摘要

目的

我们希望制定与年龄相关的参考（临界）值及一种算法，以识别任何原因导致的甲状腺功能减退低、中、高风险婴儿。我们将促甲状腺激素（TSH）作为主要检测工具，将甲状腺素（T4）作为确证检测的一部分。我们的数据使我们能够估计出生后<24小时、24至47小时、48至71小时、72至95小时以及≥96小时新生儿的临界值。

方法

我们使用时间分辨荧光免疫分析法，通过AutoDELPHIA仪器（珀金埃尔默生命科学公司，芬兰图尔库）检测TSH和T4。检测算法：我们制定了一种用于TSH和T4检测的保守算法。在初始筛查中，我们将TSH的临界值设定为≥20微国际单位/毫升，以识别任何年龄需要对重新打孔的滤纸血标本进行确证检测的婴儿。

结果

在2002年检测的161,244例新生儿中，我们发现8,035例婴儿的TSH值≥20微国际单位/毫升。TSH值与出生后小时数的关系图显示使用多个临界值的可能性。总体发现是临界值随新生儿年龄增加而降低。

结论

基于我们的研究结果，我们得出结论，不建议对<24小时的婴儿进行检测，仅在没有其他标本时才进行检测。<24小时婴儿的高TSH值用于筛查新生儿甲状腺功能减退不可靠。我们常规规定婴儿进行TSH和T4检测时至少48小时大。如果不是，临界值必须设定为更高值以防止过多假阳性结果；然而，这增加了漏诊真正甲状腺功能减退婴儿的可能性。我们将新生儿分为甲状腺功能减退的“低”（LR）、“中”（MR）或“高”风险（HR）。TSH检测仍然是一种筛查检测；所有被确定为甲状腺功能减退MR或HR的婴儿都需要进行后续定量检测和临床评估。