Mikami-Saito Yasuko, Maekawa Masamitsu, Wada Yoichi, Kanno Tomoe, Kurihara Ai, Sato Yuko, Yamamoto Toshio, Arai-Ichinoi Natsuko, Kure Shigeo
Department of Pediatrics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Department of Pharmaceutical Sciences, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.
Mol Genet Metab Rep. 2020 Nov 5;25:100674. doi: 10.1016/j.ymgmr.2020.100674. eCollection 2020 Dec.
Newborn screening is a public health care program worldwide to prevent patients from critical illness or conditions. Tandem mass spectrometry allows multiplex, inexpensive, and rapid newborn screening. However, mass spectrometry used for newborn screening to date is not able to separate peaks of compounds with similar , which could lead to false-positive results without additional second-tier tests, such as fragmentation. We experienced three neonatal cases with high levels of markers, octanoylcarnitine and octanoylcarnitine/decanoylcarnitine ratio used to pick up possible cases of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. The babies were born consecutively in a maternity hospital. Their second acylcarnitine profiles were normal, and the genetic tests for were negative. Analysis of samples extracted from their first Guthrie cards where blood was not stained also showed peaks equivalent to octanoylcarnitine and decanoylcarnitine, indicating contamination. Environmental surveillance in the maternity ward suggested that essential oils used there might contain the contaminated compound. LC-HRMS/MS and analysis revealed that false-positive results might be due to contamination with the essential oils in Guthrie cards, and causal agents were sphinganine (d17:0) and 2-[2-hydroxyethyl(pentadecyl)amino]ethanol. Thus, health care providers should be cautioned about use of essential oils when collecting blood samples on Guthrie cards. False-positive results can waste costly social resources and cause a physical and psychological burden for children and parents.
新生儿筛查是一项全球范围内的公共卫生保健项目，旨在预防患者患上严重疾病或病症。串联质谱法可实现多重、低成本且快速的新生儿筛查。然而，迄今为止用于新生儿筛查的质谱法无法分离具有相似结构的化合物峰，这可能会导致在没有额外的二线检测（如碎片分析）的情况下出现假阳性结果。我们遇到了三例新生儿病例，其用于筛查中链酰基辅酶A脱氢酶（MCAD）缺乏症可能病例的标志物辛酰肉碱和辛酰肉碱/癸酰肉碱比值水平较高。这些婴儿在一家妇产医院相继出生。他们的第二次酰基肉碱谱正常，相关基因检测结果为阴性。对从他们第一张未被血液污染的格思里卡片（Guthrie card）中提取的样本进行分析，也显示出与辛酰肉碱和癸酰肉碱相当的峰，表明存在污染。对妇产病房的环境监测表明，那里使用的精油可能含有被污染的化合物。液相色谱-高分辨质谱联用（LC-HRMS/MS）和相关分析表明，假阳性结果可能是由于格思里卡片被精油污染所致，致病因子为鞘氨醇（d17:0）和2-[2-羟乙基（十五烷基）氨基]乙醇。因此，在使用格思里卡片采集血样时，应提醒医护人员注意精油的使用。假阳性结果会浪费昂贵的社会资源，并给儿童及其父母带来身心负担。
