CONFERENCE--ISOLATED FETAL CELLS IN MATERNAL BLOOD

从母血中恢复胎儿细胞的可能性由来已久 一直是对产前诊断感兴趣的遗传学家的目标。这将会 将产前诊断(至少对细胞遗传学疾病)扩展到 整个人口，而不仅仅是那些风险增加的人。1979年， Hertzenberg和他的同事使用流分类技术恢复 具有父系但不含母系人类白细胞抗原A2抗原的淋巴细胞，因此 可能是胎儿出身的。然而，相当大的怀疑态度 坚持是因为确认胎儿来源是基于Y染色质 分析。在近十年的表面上不活动之后，几个团体 最近使用了聚合酶链式反应(PCR)来显示胎儿 母血中很可能存在细胞。第一个这样做的群体是 Lo等人的研究，他们使用嵌套引物进行Y序列。女人 事实证明，怀孕的男性胎儿更有可能表现出Y特有的信号 而不是怀上女性胎儿。我们大学的候选人单元 田纳西集团以及其他人正在追求的是有核胎儿红 细胞(红细胞)因此，我们使用了原位荧光技术 与染色体特异DNA探针的杂交(FISH)。在我们的一家 第一次成功，在CVS之前采集血液样本并进行流动分类 发现了三体18细胞。使用不同的浓缩策略分离 有核的红细胞与鱼结合，其他人随后 还检测到了胎儿非整倍体。在这次会议上，我们将回顾 胎儿细胞复苏的科学基础和临床现状 申请。所有寻求恢复各种细胞类型的活动工作人员 都会被邀请。我们将探索文章背后的科学基础。 胎儿细胞(滋养层细胞、淋巴细胞、有核红细胞)进入 母体循环、分流的科学基础等 富集技术、原位杂交的缺陷和潜力 用于诊断。以及临床前的道德和后勤要求 引言。会议应首先对以下方面进行总体概述 历史方面的问题。接下来，我们将考虑胎盘发育， 包括生理和解剖学的发展可能有利于 一种细胞类型与另一种细胞类型的胎儿循环中的通道。 母亲和胎儿之间的免疫信号将被视为一条线索 用于解释母体血液中的胎儿细胞现象。海流 寻求恢复胎儿细胞的10-12个小组的工作状态将是 已审阅。随后将深入审议以下两个领域 根本性的进展似乎对临床应用至关重要。其中一个涉及到 稀有细胞的浓缩，即通过流动分选或磁化细胞 分离。另一种是原位杂交，尤其是多基因原位杂交。 色彩技巧。然后，我们将考虑基本技术基础流程 分类，荧光探针的使用，最后，In的应用 原位杂交以流动分选细胞。我们讨论的基本内容将是 对这项技术的敏感性和特异性进行评估 普通人口。总体而言，我们预计这次会议将更新当前 在该领域的地位，帮助确定几个中最赚钱的 可能的方法，并允许制定合作研究 将包括交换样本以确定敏感性和特异性。

The possibility of recovering fetal cells from maternal blood has long been a goal for geneticists interested in prenatal diagnosis. This would extend prenatal diagnosis (at least for cytogenetic disorders) to the entire population, not merely those at increased risk. In 1979, Hertzenberg and colleagues used flow-sorting techniques to recover lymphocytes having a paternal but not maternal HLA-A2 antigen, thus presumably being fetal in origin. However, considerable skepticism persisted because confirmation of fetal origin was based on Y chromatin analysis. After nearly a decade of ostensible inactivity, several groups have recently used polymerase chain reaction (PCR) to show that fetal cells very likely exist in maternal blood. The first group to do so was that of Lo et al., who used nested primers for a Y sequence. Women carrying male fetuses proved far more likely to show a Y-specific signal than those carrying female fetuses. The candidate cell our University of Tennessee group as well as others are pursuing is the nucleated fetal red cell (erythroblast.) We thus are employing fluorescence in situ hybridization (FISH) with chromosome-specific DNA probes. In one of our first successes, a blood sample taken prior to CVS and flow-sorted revealed trisomy 18 cells. Using various enrichment strategies to isolate nucleated red cells in combination with FISH, others have subsequently detected fetal aneuploidies also. In this conference, we will review the scientific basis of fetal cell recovery, and current state of clinical application. All active workers seeking to recover the various cell types will be invited. We shall explore the scientific basis underlying passage of fetal cells (trophoblasts, lymphocytes, nucleated red blood cells) into the maternal circulation, the scientific basis of flow sorting and other enrichment techniques, the pitfalls and potential of in situ hybridization for diagnosis. and ethical and logistical requirements before clinical introduction. The conference shall begin with a general overview of historical aspects. Next, we shall consider placenta development, including physiological and anatomical developments that could favor passage in the fetal circulation of one cell type versus another. Immunologic signals between mother and fetus will be considered as a clue for explaining the phenomena of fetal cells in maternal blood. The current status of work by the 10-12 groups seeking to recover fetal cells will be reviewed. In-depth consideration will then focus on two areas in which fundamental advances appear pivotal to clinical application. One involves enrichment for rare cells, namely by either flow sorting or magnetic cell separation. The other is in situ hybridization (ISH), especially multi- color techniques. We will then consider basic technology underlying flow sorting, use of fluorescent probes and, finally, the application of in situ hybridization to flow sorted cells. Underlying our discussion will be assessment of the sensitivity and specificity of this technology in the general population. Overall, we expect this conference to update current status in the field, help identify the most profitable of several potential approaches and allow formulation of collaborative studies that will include exchange of samples to determine sensitivity and specificity.