Semi-Automated Prenatal Screening Using Maternal Blood

使用母血进行半自动产前筛查

• 批准号: 6727528
• 负责人: Fatima Aziz Merchant
• 金额: $ 38.59万
• 依托单位: ADVANCED DIGITAL IMAGING RESEARCH, LLC
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6727528
• 关键词: bioimaging /biomedical imaging; biomedical automation; biomedical equipment development; cell morphology; cell sorting; chromosome disorders; clinical research; cytodiagnosis; cytogenetics; diagnosis design /evaluation; digital imaging; embryo /fetus cell /tissue; female; fluorescence microscopy; fluorescent in situ hybridization; genetic screening; human subject; image processing; pregnancy circulation; prenatal diagnosis

DESCRIPTION (provided by applicant): Scientists have documented the phenomenon of fetal ceils in maternal blood, and envisioned using them for noninvasive prenatal screening. A key limiting factor is the small number of fetal cells in the maternal circulation, making fetal cell isolation difficult and limiting the accuracy of genetic analysis. Current emphasis is on simple, practical and reproducible methods for enrichment and genetic testing of fetal cells. The goal of this project is to develop simple semi-automated methods for enrichment, detection, and diagnosis of fetal cells in maternal blood. This project combines recent advances in fetal progenitor cell research, with a novel enrichment approach, and speedy automated cell detection for prenatal genetic analysis. In the Phase I study we evaluated the feasibility of automatically detecting May-Giemsa stained nucleated red blood cells (NRBCs) using transmitted light microscopy, followed by fetal gender and/or aneuploidy detection via fluorescent in-situ hybridization (FISH). Our results demonstrated that NRBCs are present in the maternal blood stream during pregnancy, and can be effectively enriched to proportions that are conducive to automated cell detection. We also observed that these cells may not be the ideal target cell, because most of these cells are at late stages of differentiation and undergoing apoptosis. Moreover, we found that the suitability of NRBCs for FISH analysis was highly variable as it is related to its state of differentiation. Consequently, we evaluated the potential of fetal progenitor cells as an alternative cell type for prenatal screening. For separation and enrichment, we employed a more simple isolation method that would allow for detection of more that one fetal progentior cell type. We adopted the Rosette Method (StemCell Technologies, Inc) to achieve the selective enrichment of hematopoietic progenitor cell types from whole blood with reduced cell loss. The enriched samples were then successfully processed via FISH to identify male fetal cells in maternal blood. In the Phase II study, we will (i) evaluate automated analysis for detection efficiency of fetal cells based on the presence of FISH signals in the clinical environment, and (ii) relocate fetal cells identified in aim 1 and record fetal cell descriptors based on cellular shape, density, and size. This information will then be used to further develop automated parameters for morphological identification of progenitor fetal cells, and (iii) based on the results of aim 1 and 2, we will implement the final modifications and/or optimizations to fully develop a semi-automated imaging system for the detection and analysis of fetal cells in maternal blood using transmitted and fluorescence microscopy. The ultimate goal of much of the current research in medical cytogenetics is to make low-cost, low-risk prenatal genetic screening widely available. This project will develop instrumentation that will be vital in the realization of this goal. The innovative technological approach presented here has the potential to revolutionize the future of prenatal diagnosis.

描述（由申请人提供）： 科学家已经记录了胎儿血液中胎儿天花板的现象，并设想使用它们进行非侵袭性产前筛查。一个关键的限制因素是孕产妇循环中少量的胎儿细胞，这使得胎儿细胞分离变得困难并限制了遗传分析的准确性。当前的重点是胎儿细胞富集和基因检测的简单，实用和可重复的方法。 该项目的目的是开发简单的半自动化方法来富集，检测和诊断孕产妇血液中的胎儿细胞。该项目将胎儿祖细胞研究的最新进展与一种新颖的富集方法和快速的自动细胞检测结合在一起，以进行产前遗传分析。 在第一阶段的研究中，我们评估了使用透射光学显微镜自动检测May-Giemsa染色的红细胞（NRBC），然后通过胎儿性别和/或非倍倍型检测通过荧光检测，并通过荧光检测（FISH）。我们的结果表明，怀孕期间的母体血流中存在NRBC，并且可以有效地富集有利于自动细胞检测的比例。我们还观察到这些细胞可能不是理想的靶细胞，因为这些细胞中的大多数处于分化和凋亡的晚期阶段。此外，我们发现NRBC对于鱼类分析的适用性与其分化状态有关，因此具有很高的变化。因此，我们评估了胎儿祖细胞作为产前筛查的替代细胞类型的潜力。为了分离和富集，我们采用了一种更简单的分离方法，该方法将允许检测到一种胎儿进展细胞类型。我们采用了玫瑰花结（Stemcell Technologies，Inc），以从全血中从全血中释放造血祖细胞类型的选择性富集，并减少细胞损失。然后通过鱼成功处理富集的样品，以鉴定孕妇血液中的雄性胎儿细胞。 在第二阶段的研究中，我们将（i）根据临床环境中鱼信号的存在评估自动分析，以评估胎儿细胞的检测效率，以及（ii）基于细胞形状，密度和大小，在AIM 1和记录胎儿细胞描述中鉴定的胎儿细胞。然后，该信息将用于进一步开发自动参数，以鉴定祖细胞细胞的形态学鉴定，（iii）基于AIM 1和2的结果，我们将实施最终修饰和/或优化，以完全开发半自动化成像系统，以使用传输和荧光的孕产妇中胎儿的检测和分析胎儿细胞。 当前大部分医学细胞遗传学研究的最终目标是使低成本，低风险的产前遗传筛查广泛可用。该项目将开发对实现这一目标至关重要的工具。这里提出的创新技术方法有可能彻底改变产前诊断的未来。