Rapid Test Kit for Measurement of Urinary Iodine

碘是甲状腺激素的重要组成部分，甲状腺激素在妊娠期、婴儿期和整个生命过程中对正常生长、发育和新陈代谢都是必需的。全世界有超过10亿人患有缺碘症，孕期和婴儿期缺碘症是造成智力损伤和脑损伤的一个主要原因。碘缺乏症对发育中的大脑造成影响，导致数百万人生活无望，持续发育不足。在世界范围内，碘缺乏是造成脑损伤的最重要的可预防原因。因此，准确评估人群碘状况对公共卫生政策和碘营养临床研究具有重要意义。尿碘浓度（UIC）直接反映膳食碘摄入量，是世界范围内评估人群碘状况最常用的指标。目前使用的尿碘测量方法要么需要昂贵的仪器和合格的人员（电感耦合等离子体质谱，仪器核活化分析），要么需要氧化样品消化，以消除潜在的干扰，然后再使用Sandell和Kolthoff最初引入的动力学比色法进行分析。Sandell-Kolthoff方法需要几个小时的样品消化过程，涉及非常苛刻的化学物质和高温，因此仅限于设备齐全的实验室。这需要将冷冻的尿液样本运送到中心实验室进行分析，这增加了复杂性和成本，并且可能需要几天到几周的时间才能获得测试结果。因此，迫切需要一种易于使用和具有成本效益的尿碘现场检测方法，以支持全球卫生界的使命。Lynntech正在开发一种简单的创新测试试剂盒，用于快速准确地测量尿碘浓度。在第一阶段的SBIR研究中，我们开发并演示了一种快速测试试剂盒，该试剂盒由干燥测试盒组成，只需三个简单的步骤即可使用廉价的色度计测量UIC。该检测试剂盒包含许多具有挑战性的步骤，涉及尿碘定量的解决方案，包括检测ppb水平的碘存在显著较高浓度的潜在干扰阴离子和有色化合物，以及去除有机基质。该SBIR项目第二阶段的目标是将该技术转化为一种实用的检测试剂盒，通过开发一种用于大规模生产检测试剂盒的设计，并使用大量学龄儿童、育龄妇女和孕妇的尿液样本对原型检测试剂盒进行测试。测试试剂盒的适用性将通过与标准分光光度法所得结果的比较来验证。这项技术可以方便地更频繁地测量UIC，并在个人基础上提供对碘缺乏症的准确评估，从而可能对公共卫生产生重大影响。

Iodine is an essential component of the thyroid hormones which are necessary for normal growth, development, and metabolism during gestation, infancy, and throughout life. Iodine deficiency disorders (IDD) affect more than a billion people worldwide, and IDD during pregnancy and infancy are a major cause of intellectual impairment and brain damage. Iodine deficiency, through its effects on the developing brain, has condemned millions of people to a life of few prospects and continued underdevelopment. On a worldwide basis, iodine deficiency is the single most important preventable cause of brain damage. Thus, an accurate assessment of population iodine status is necessary to inform public health policies and clinical research on iodine nutrition. Urinary iodine concentration (UIC) directly reflects dietary iodine intake and is the most common indicator used worldwide to assess population iodine status. Currently used methods for urinary iodine measurement either require expensive instrumentation with qualified personnel (inductively coupled plasma-mass spectrometry, instrumental nuclear activation analysis) or oxidative sample digestion to remove potential interferences prior to analysis by a kinetic colorimetric method originally introduced by Sandell and Kolthoff. The Sandell–Kolthoff method requires hour(s) long sample digestion process involving very harsh chemicals and high temperature and are therefore limited to well-equipped laboratories. This requires shipping frozen urine sample to the central laboratories for analysis, which adds complexity, cost and may take several days to weeks to get test results. Thus, there is a critical need for an easy-to-use and cost-effective method for on-site testing of urinary iodine to support the mission of the global health communities. Lynntech is developing a simple innovative test kit for rapid and accurate measurement of urinary iodine concentration. In a Phase I SBIR study we have developed and demonstrated a rapid test kit consisting of dry test cartridges that only requires three simple steps for measurement of UIC using an inexpensive colorimeter. This test kit incorporates solutions to many challenging steps involved with the quantitation of urinary iodine, including detection of ppb levels of iodide in presence significantly higher concentration of potentially interfering anions and colored compounds, as well as removal of organic matrix. The goal of this Phase II of this SBIR project is to transition the technology into a practical test kit by developing a design for scaled up production of the test cartridges and testing the prototype test kit with large number of urine samples from school-aged children, reproductive-aged women, and pregnant women. The applicability of the test kit will be validated by comparing the results with those obtained by a standard spectrophotometric method. This technology can potentially make a significant impact on public health by making it possible to conveniently measure UIC much more frequently and providing accurate assessment of iodine deficiency at an individual basis.