A comparison of in vitro culture of fetal nucleated erythroblasts from fetal chorionic villi and maternal peripheral blood for noninvasive prenatal diagnosis.

OBJECTIVE

We tested the feasibility of the in vitro culture of fetal nucleated erythroblasts from maternal blood for noninvasive prenatal screening as a substitute for culturing fetal nucleated erythroblasts from fetal villi.

METHOD

Nucleated blood cells separated via Percoll from 52 samples of fetal villi and maternal peripheral blood were cultured with or without magnetic-activated cell sorting glycophorin A (MACS-GPA+), and detected by an anti-hemoglobin-epsilon (FITC) antibody. Gender of the epsilon-positive cells were identified by FISH and further confirmed by PCR of the villi karyotype. Developmental stages of nucleated erythroblasts from villi and blood with MACS-GPA+ were analyzed by Wright-Giemsa staining.

RESULTS

In the maternal blood, epsilon-positive cells were found in 4 and 24 cultured samples with and without MACS-GPA+, respectively. Also, Y-signals were visualized in 3 out of 4 and in 15 out of 24 cases in the epsilon-positive cells. Although epsilon-positive cells were found in all villus samples irrespective of MACS-GPA+ sorting, Y-signals were visualized in 31 out of 52 cases. Proerythroblasts and basophilic erythroblasts occupied 7 and 1% in fetal and maternal samples (with MACS-GPA+), respectively.

CONCLUSIONS

The in vitro culturing of fetal nucleated erythroblasts from maternal blood is not feasible with the current techniques for prenatal diagnosis, because the fetal nucleated erythroblast is not well developed in vitro. This may be attributed to the low proportion of these erythroblasts at an early stage in the fetal circulation and the low permeability of these cells to the maternal blood.