Enrichment, Identification And Isolation Of Fetal Nucleated Red Blood Cells From Maternal Blood

Objective: To compare mononuclear cells labeled by CD71 single-staining method with CD71 and CD45 double-staining one, and study the relationship between the proportion of fetal cells and gestational age.Methods: Samples of peripheral blood in 81 women of 7~34 gestational weeks were collected. The proportion of NRBCs was sorted by flow cytometry. The blood from nonparous women and the cord blood were compared as controls.Results: Frequency of CD71+ and CD45 dim cells in maternal peripheral blood during 7~34 week's gestation was (0.107±0.063)×10-2. There were significant difference among the gravida and nonparous and newborn cord blood. Frequency of CD71+ and CD45 dim cells was the highest at 17~18 week's gestation, (0.144±0.096)×10-2.Conclusions: Different frequency of NRBCs was presented in women's peripheral blood of various gestational weeks. The frequency of NRBCs in peripheral blood of 17~18 gestational weeks was the highest. The best optimum time of prenatal diagnosis using fetal cell in maternal blood was at the 17~18 gestational weeks. Objective: To identify epsilon-haemoglobin-chain(Hbε) positive nucleated red blood cells (NRBCs) in the maternal peripheral blood after enriching fetal nucleated red blood cells (FNRBCs) via flow cytometry, and to find out the more suitable time to perform the identification and isolation.Methods: To collect the maternal peripheral blood during 10~25 gestational weeks to enrich FNRBCs via density gradient and flow cytometry, then to identify and isolate Hbεpositive NRBCs.Results: Hbεpositive NRBCs were identified in 13 cases among 14 cases during 10~15 gestational weeks. The positive rate was 92.86%. Among positive cases, the average number of Hbεpositive NRBCs was 6.92±2.75 per 10ml maternal peripheral blood. Meanwhile, Hbεpositive NRBCs were identified in 9 cases among 12 cases during 16~25 gestational weeks. The positive rate was 75.00%. Among positive cases, the average number of Hbεpositive NRBCs was 2.67±1.32 per 10ml maternal peripheral blood.Conclusions: After enriching FNRBCs via flow cytometry, Hbεpositive NRBCs could be identified in maternal peripheral blood. It seemed that the more suitable time of identification and isolation was during 10~15 gestational weeks.