Using Multi-Spectral Imaging with Microchip Electrophoresis to Accurately Screen Newborns for Sickle Cell Disease

项目摘要 血红蛋白（Hb）疾病是世界上最常见的单基因疾病之一。近7%的 世界人口携带Hb基因变异。镰状细胞病（SCD）发生时，血红蛋白突变遗传 同源突变（HbSS）或与另一种β-珠蛋白基因突变配对。全球估计有40万婴儿 每年出生的婴儿中有70%-75%患有SCD，其中70%-75%在撒哈拉以南非洲（SSA）。据估计，50-90%的 SSA在5岁生日前死亡，其中70%的死亡是可以预防的。SCD的有效管理包括 早期诊断和遗传咨询，以及重要的全国新生儿筛查（NBS）。NBS 在资源丰富的国家，利用集中实验室的项目已经大大降低了SCD的死亡率。 NBS需要在存在高胎儿Hb（HbF）的情况下灵敏地检测相对低水平的Hb变体。 在存在高水平（高达90%）HbF的情况下，应准确识别正常HbA和镰状HbS。 目前用于Hb变体测试的金标准是高效液相色谱法（HPLC），其 需要昂贵的设备和试剂、训练有素的人员和现代化的实验室。在低- 在资源丰富的地区，很少有中心实验室可以进行昂贵的Hb检测。测试不适用于 在大医院或大城市以外出生的婴儿比例很大。对负担得起的、 便携式、易于使用、准确的床旁（POC）检测，以促进分散式Hb检测， 国家统计局的全国性计划。2019年，世界卫生组织（WHO）将Hb电泳列为 低收入和中等收入国家的基本体外诊断。我们开发了一种POC微芯片 电泳Hb变体测试系统，微芯片电泳（MCE），产品名称为“Gazelle Hemex Health，Inc. MCE报告Hb表型、Hb定量（%Hb）和解释性 显示基因型的陈述（如SCD、镰状细胞性状或正常）。MCE已得到广泛验证 用于血红蛋白病，包括SCD、血红蛋白E病和地中海贫血。新生儿及以下婴儿 6周龄具有非常低浓度的Hb变体，而不是高浓度的Hb F，因此 需要改进以降低检测限（LoD），以支持NBS在全球范围内的项目。通过 将LoD从目前的10%降低到2%，新生儿和婴儿可以用这种负担得起的 系统SBIR第一阶段的创新是多光谱成像和基于机器学习的集成 MCE的数据分析能力，以开发MCE+，准确筛查新生儿常见的Hb变异。我们 提出以下目标：目标1：将多光谱成像和机器学习算法集成到 MCE平台，用于识别和定量新生儿血红蛋白变体。目标2：执行 MCE+多光谱新生儿筛查系统的临床测试。该项目的意义在于MCE+是 唯一负担得起的用于定量和客观血红蛋白变体检测的POC系统，可以在 出生

PROJECT SUMMARY Hemoglobin (Hb) disorders are among the world's most common monogenic diseases. Nearly 7% of the world’s population carry Hb gene variants. Sickle cell disease (SCD) arises when Hb mutations are inherited homozygously (HbSS) or paired with another β-globin gene mutation. Globally, an estimated 400,000 babies are born annually with SCD, and 70%-75% are in sub-Saharan Africa (SSA). It is estimated that 50-90% in SSA die by their 5th birthday, 70% of these deaths are preventable. Effective management of SCD involves early diagnosis, and genetic counselling, and, importantly, nationwide newborn screening (NBS). NBS programs utilizing centralized laboratories have dramatically reduced SCD mortality in high-resource countries. NBS requires sensitive detection of relatively low levels of Hb variants in the presence of high fetal Hb (HbF). Normal HbA and sickle HbS should be accurately identified in the presence of high levels (up to 90%) of HbF. The current gold standard for Hb variant testing is high-performance liquid chromatography (HPLC), which requires expensive equipment and reagents, highly trained personnel, and modern laboratories. In low- resource regions, very few centralized laboratories can perform costly Hb testing. Testing is not available to the large percentage of infants born outside of a major hospital or city. There is an unmet need for affordable, portable, easy-to-use, accurate, point-of-care (POC) tests to facilitate decentralized Hb testing to enable nationwide NBS programs. In 2019, the World Health Organization (WHO) listed Hb electrophoresis as an essential in vitro diagnostic in low- and middle-income countries. We have developed a POC microchip electrophoresis Hb variant testing system, MicroChip Electrophoresis (MCE), under the product name “Gazelle Hb Variant” by Hemex Health, Inc. MCE reports Hb phenotype, Hb quantification (%Hb), and an interpretive statement showing genotype (such as SCD, Sickle Cell Trait, or Normal). MCE has been extensively validated for hemoglobinopathies, including SCD, hemoglobin E disease, and thalassemia. Newborns and infants below 6 weeks of age have very low concentrations of Hb variants other than Hb F which is high, therefore an improvement to lower the limit of detection (LoD) is needed to support NBS programs worldwide. By decreasing the LoD from the current 10% to 2%, newborns and infants can be screened with this affordable system. The innovation in this SBIR Phase I is the integration of multi-spectral imaging and machine learning based data analysis capability to MCE to develop MCE+ to accurately screen newborns for common Hb variants. We propose the following aims: Aim 1: Integrate multi-spectral imaging and machine learning algorithm into the MCE platform to enable identification and quantification of hemoglobin variants in newborns. Aim 2: Perform clinical testing of the MCE+ multi-spectral newborn screening system. Significance of this project is that MCE+ is the only affordable POC system for quantitative and objective hemoglobin variant testing that allows screening at birth.