特异性抗体标记法检测母血中的胎儿细胞

目的　探讨免疫组化法检测孕妇外周血中胎儿有核红细胞 (nucleated red blood cell,NRBC)进行产前基因诊断的可行性。方法　对 30名孕 8～ 2 6周孕妇外周血进行密度梯度离心 ,初步富集胎儿 NRBC,细胞涂片离心机制片 ,胎儿血红蛋白 (fetal hemoglobin,Hb F)特异性抗体标记、识别 ,显微操作法获取全部阳性细胞 ,经全基因组扩增后 ,产物进行性别检测及杜氏肌营养不良 (Duchenne musculardystrophy,DMD)的基因诊断。结果　 30名孕 8～ 2 6周孕妇外周血中均发现与 Hb F呈阳性反应的胎儿NRBC。性别检测结果 30名孕妇中共检出 17名男性胎儿 ,13名女性胎儿 ,结果经孕妇引产及羊水细胞对照证实准确率达 10 0 % ,并完成 8例 DMD的产前基因诊断。结论　免疫组化法以胎儿血红蛋白 Hb Fγ链抗体标记胎儿的 NRBC进行产前基因诊断是一种很有应用前景的方法。

Use of specific antibody to detect fetal erythroblasts in maternal circulation

OBJECTIVE: To investigate the feasibility of using immunohistochemical technique to detect the presence of fetal erythroblasts in the maternal circulation for prenatal diagnosis. METHODS: Maternal blood was obtained from 30 pregnant women at 8 to 26 weeks of gestation. Nucleated red blood cells (NRBCs) were separated with Percoll using a discontinuous density gradient method, and then smeared on microscope slides using cytocentrifugation. Slides were stained with antibody against the gamma-chain of fetal hemoglobin (HbF). All positive NRBCs were collected by micromanipulator under microscopic observation, and then amplified by improved primer extension preamplification(PEP). Sex and Duchenne's musclar dystrophy (DMD) genetic diagnosis were determined from a small aliquot of the PEP reaction. RESULTS: NRBCs stained with HbF were found in all of the blood from the 30 pregnant women at 8 to 26 weeks of gestation. 17 male fetuses and 13 female fetuses were detected in the 30 cases. These results coincided with those of induced labor or amniotic fluid control, and 8 fetuses at the risk of DMD were diagnosed. CONCLUSION: This diagnostic method using immunohistochemical technique to mark fetal NRBC shows good application prospects.