磁激活细胞富集孕妇外周血中胎儿有核红细胞行产前诊断

Enrichment of fetal nucleated red blood cells from maternal peripheral blood by magnetically activated cell sorting for prenatal diagnosis.

目的 :研究磁激活细胞分离富集孕妇外周血胎儿有核红细胞进行产前诊断的可行性。方法 :2 1名孕 13 2 9周孕妇及 5名未妊娠妇女外周血 4 6ml,经单密度梯度离心和激活细胞分离 ,收集阳性组分抽提DNA ,经PCR扩增预测胎儿性别 ,并以出生后婴儿性别验证预测性别的准确性。结果 :以Y染色体特异引物介导的PCR扩增Y染色体特异片段检出的最低限量为 3 4个男性细胞或 3 4个男性细胞 / 3 5× 10 4 女性细胞。 2 1名孕妇分娩 13名男婴、8名女婴。男性DNA在 12名孕男胎孕妇外周血有核红细胞中被检出 ,在 1名孕男胎孕妇中未被检出 ;而在 8名孕女胎孕妇外周血有核红细胞及 5名未孕妇女外周血中均未检出男性DNA。预测胎儿性别的准确度为 95 2 3% ,假阴性率为 4 76 %。结论 :磁激活细胞分离富集孕妇外周血胎儿有核红细胞是一简单、快速、价廉的有效方法 ,被分离细胞DNA经PCR扩增后可用于胎儿性别的非侵入性产前诊断。

To study the possibility of fetal nucleated red blood cells enriched by magnetically activated cell sorting from maternal peripheral blood for prenatal diagnosis.Methods:4-6ml peripheral blood was obtained from 21 pregnant women between 13 and 28 weeks of gestation,and from 5 non-pregnant women as control.After single density gradient centrifugation followed by magnetic cell sorting. DNA was extracted from each enriched fetal nucleated erythrocytes for PCR amplification of Y chromosome-specific DNA to expect fetal sex.The accuracy of expected fetal sex could be verified by the babies'sex at delivery.Results: Ahighly specific PCR method primed by Y chromosome-specific primers was used,sensitive enough to detect Y chromosome specific DNA fragment in 3-4 male cells or in 3-4 male cells among 3.5×10 4 female cells. Of 21 pregnant women,13 delivered male babies and 8 delivered female babies. Male DNA was detected in the nucleated erythrocytes from maternal peripheral blood of 12 pregnant women with male fetuses and not detected in that from maternal peripheral blood of one pregnant woman with male fetus.Male DNA was not detected in the nucleated erythrocytes from maternal peripheral blood of 8 pregnant women with female fetuses and in maternal peripheral blood of 5 non-pregnant women.The accuracy rate of expected fetal sex was 95.23%. The false-negative rate was 4.76%.Conclusion:Enrichment of retal nucleated erythrocytes from maternal peripheral blood by magnetically activated cell sorting was a simple,rapid and inexpensive isolation method. The DNA from the enriched fetal nucleated erythrocytes could be amplified by PCR for non-invasive prenatal diagnosis of fetal sex.