Rapid Test Kit for Measurement of Urinary Iodine

碘是甲状腺激素的基本成分，在孕期、婴儿期和一生中对正常的生长、发育和新陈代谢是必不可少的。碘缺乏症(IDD)影响着全球10多亿人，而孕期和婴儿期的IDD是智力障碍和脑损伤的主要原因。碘缺乏通过对发育中的大脑的影响，使数百万人的生活前景渺茫，继续处于不发达状态。从世界范围来看，缺碘是导致脑损伤的最重要的可预防原因。因此，对人群碘状况的准确评估对于公共卫生政策和有关碘营养的临床研究是必要的。尿碘浓度(UIC)直接反映膳食碘摄入量，是世界范围内用来评估人群碘状况的最常用指标。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、仪器核激活分析)，要么需要氧化样品消化以消除潜在的干扰，然后用Sandell和Kolthoff最初引入的动力学比色法进行分析。桑德尔-科尔霍夫方法需要长达一小时(S)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。这需要将冷冻的尿样运往中央实验室进行分析，这增加了复杂性和成本，可能需要几天到几周的时间才能获得检测结果。因此，迫切需要一种易于使用和成本效益高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、创新的检测试剂盒，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检测试剂盒，该试剂盒由干试纸盒组成，只需三个简单的步骤即可使用廉价的色度计测量UIC。该试剂盒结合了许多与尿碘定量相关的具有挑战性的步骤的解决方案，包括在存在明显更高浓度的潜在干扰阴离子和有色化合物的情况下检测ppb水平的碘，以及去除有机基质。SBIR项目第二阶段的目标是将该技术转化为实用的检测试剂盒，方法是开发一种用于扩大测试盒生产规模的设计，并使用学龄儿童、育龄妇女和孕妇的大量尿样测试原型测试试剂盒。测试试剂盒的适用性将通过将结果与标准分光光度方法的结果进行比较来验证。这项技术可能会对公众健康产生重大影响，因为它可以更方便、更频繁地测量尿碘含量，并提供对个人缺碘的准确评估。

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.