Immunoassay for diagnosis of Babesia infection

描述（由申请方提供）：本项目旨在开发用于临床诊断试验的巴托溴铵抗体的酶免疫测定法（EIA）。巴贝斯虫病是一种新出现的蜱传寄生虫病，可能导致免疫功能低下或其他虚弱患者的严重至致命疾病，并且可能在流行地区高达1%的人口中亚临床地携带在血液中。最近发生的致命的输血传播巴贝虫病病例也使人们将这种病原体确定为一种重大威胁 血液供应。然而，目前没有商业的、经验证的和FDA批准的检测可用于B。显微镜巴贝斯虫病目前通过免疫荧光染色、血涂片显微镜检查和/或PCR进行诊断。这些程序都不容易适应常规临床实验室使用。我们建议使用新的合成B开发基于微孔板的ELISA。授权给Immunetics的microti抗原先前已被证明是诊断上重要的标志物。将在来自非流行区和其他对照的献血者血清中评估抗原的特异性。将使用来自美国东北部和中西部流行地区的巴贝斯虫病患者的充分表征的血清评价检测试剂盒性能。为了鉴定可能进一步提高检测灵敏度的免疫显性表位，我们鉴定了一系列推定的巴贝斯虫抗原序列，这些序列将以重叠肽文库形式用巴贝斯虫病患者血清进行筛选，这一策略导致发现了许多具有诊断价值的抗原。我们还提出了策略，以确定其他致病性巴氏杆菌物种，B的免疫优势表位。分歧者/MO-1和B。duncani/WA 1.通过这些策略发现的新的免疫显性表位将被合成为具有适当结构的肽抗原，用于掺入当前的测定形式中，这使得能够在单孔测定中组合多种不同的肽。一旦开发出具有符合临床诊断要求的灵敏度和特异性特征的单孔检测格式，我们将为II期临床试验和FDA申报做准备。

DESCRIPTION (provided by applicant): This project is aimed at development of an enzyme immunoassay (EIA) for antibodies to Babesia for use as a clinical diagnostic test. Babesiosis is an emerging tick-borne parasitic disease which may cause severe to fatal illness in immunocompromised or otherwise weakened patients, and may be carried in the blood subclinically in up to 1% of the population in endemic areas. Recent cases of fatal transfusion-transmitted babesiosis have also led to the identification of this pathogen as a significant threat to the blood supply. However, currently no commercial, validated and FDA approved tests are available for B. microti. Babesiosis is currently diagnosed by immunofluorescence staining, microscopy of blood smears, and/or PCR. None of these procedures are easily adaptable to routine clinical laboratory use. We propose to develop a microplate-based ELISA using novel synthetic B. microti antigens licensed to Immunetics that have previously been shown to be diagnostically significant markers. Specificity of the antigens will be assessed in blood donor sera from nonendemic areas and other controls. Assay performance will be evaluated on well-characterized sera from babesiosis patients from both U.S. Northeast and Midwest endemic regions. To identify immunodominant epitopes that may further improve assay sensitivity, we have identified a series of putative Babesia antigenic sequences that will be screened with babesiosis patient serum in an overlapping peptide library format, a strategy that has led to discovery of a number of antigens of diagnostic value. We also propose strategies to identify immunodominant epitopes of other pathogenic Babesia species, B. divergens/MO-1 and B. duncani/WA1. Novel immunodominant epitopes discovered through these strategies will be synthesized as peptide antigens with an appropriate structure for incorporation into current assay formats, which enable combination of multiple distinct peptides in a single-well assay. Once a single-well assay format is developed with sensitivity and specificity characteristics consistent with clinical diagnostic requirements, we will prepare for clinical trials and FDA submission in Phase II.