R&D- MEDICAL: BIOMEDICAL (BASIC RESEARCH)

本项目旨在开发一种用于血液中微小巴贝斯虫抗体筛查的酶免疫分析方法(ELISA)。人类巴贝斯虫病是一种类似疟疾的疾病，由巴贝斯虫属的各种原生动物感染红细胞所致。美国报告的大多数人类感染是由微小杆菌引起的，这种病毒在美国东北部和中北部的部分地区流行。B.Microti感染通常是无症状的，但也可以发展为严重疾病甚至死亡，特别是在免疫抑制、脾功能不全或年长的人。 最近发生的通过输血传播的巴贝斯虫病致死性病例已导致将这种病原体确定为对血液供应的重大威胁。目前还没有商业的、经过验证的和FDA批准的微结核杆菌检测，而且捐赠者的问卷在防止巴贝斯虫进入血液供应方面被证明是无效的。目前使用的免疫荧光、显微镜和聚合酶链式反应等检测方法很难适用于高通量血液筛查。这项建议描述了一种基于微板的巴贝斯虫ELISA的开发和临床试验，该方法可以在自动化、高通量平台上进行，具有血液筛查所需的灵敏度和特异性。该研究计划有五个具体目标：1)完成化验开发，从优化的研发原型到可生产的试剂盒，2)扩大生产规模，3)在IND临床试验中评估来自巴贝西亚流行和非流行地区献血者的化验性能，4)对血清阳性献血者进行跟踪研究，以告知献血者推迟和重返政策，以及5)准备并向FDA提交BLA申请，以获得血液筛查使用许可证。

This project is aimed at the development of an enzyme immunoassay (ELISA) for screening blood for antibodies to Babesia microti. Human babesiosis is a malaria-like illness due to infection of red blood cells by various species of protozoan parasites belonging to the genus Babesia. Most human infections reported in the United States are caused by B. microti which is endemic in parts of the northeast and north central United States. B. microti infections are often asymptomatic but can also progress to severe illness and even death, particularly in individuals who are immunosuppressed, asplenic or elderly. Recent cases of fatal transfusion-transmitted babesiosis have led to the identification of this pathogen as a significant threat to the blood supply. Currently no commercial, validated and FDA approved test are available for B. microti, and donor questionnaires have proven ineffective in preventing introduction of Babesia into the blood supply. Tests now in use including immunofluorescence, microscopy and PCR are not easily adaptable to high throughput blood screening. This proposal describes the development and clinical trial of a microplate-based Babesia ELISA which can be performed on an automated, high throughput platform, with the sensitivity and specificity required for blood screening. The research plan has five specific aims: 1) completion of assay development, proceeding from an optimized R&D prototype to a manufacturable kit, 2) manufacturing scale up, 3) evaluation of assay performance on blood donors from Babesia endemic and non-endemic areas in an IND clinical trial, 4) follow-up study of seropositive donors to inform donor deferral and re-entry policy, and 5) preparation and submission of a BLA application to the FDA for licensure for blood screening use.