Yonsei Med J.  2000 Apr;41(2):258-265. 10.3349/ymj.2000.41.2.258.

Prenatal genetic diagnosis from maternal blood: simultaneous immunophenotyping and FISH of fetal nucleated erythrocytes isolated by negative and positive magnetic activated cell sorting

• Yang YH
• Jee KJ
• Kim SK
• Park YW
• Kim IK
• Cha DH
• Chung JE
• Kim SH

• KMID: 1758518
• DOI: http://doi.org/10.3349/ymj.2000.41.2.258

Abstract

Fetal nucleated red blood cells (nRBCs) are rare in maternal circulation, but their presence constitutes a potential source of non-invasive prenatal genetic diagnosis. This study was undertaken to establish a non-invasive prenatal genetic diagnosis method using isolated fetal nRBCs. A multi-step method including triple density gradient and magnetic activated cell sorting (MACS) using CD45 and CD71, cytospin centrifugation, K-B staining, and glycophorin A-immuno fluorescence in situ hybridization (GPA-immuno FISH) was performed. The study population included 65 patients from 8 to 41 weeks of gestation, and fetal nRBC was separated from all cases. The number of fetal nRBCs retrieved was 12.8 +/- 2.7 in 8 to 11 gestational weeks, 15.2 +/- 6.5 in 12 to 18 gestational weeks, 16.4 +/- 6.5 in 19 to 23 gestational weeks, 10.6 +/- 3.2 in 24 to 28 gestational weeks, and 5.5 +/- 1.9 in 35 to 41 gestational weeks: the mean number of nRBCs collected from 20 ml of maternal peripheral blood was 13.7 +/- 6.2. The highest value of yield was 45.6% from 12 to 18 weeks gestation. The fetal sex determination confirmed by amniocentesis or chorionic villus sampling showed 100% sensitivity and 91.7% specificity for males; 91.7% sensitivity and 100% specificity for females. We showed that fetal cells can be reliably enriched from maternal blood and that they can be used for detecting specific chromosomes by FISH with a specificity superior to current non-invasive methods.

Keyword

Prenatal diagnosis; fetal nRBC; density gradient; MACS; GPA-immuno FISH

MeSH Terms

Erythrocytes/immunology*
Female
Fetal Blood/immunology*
Gestational Age
Glycophorin
Human
Immunomagnetic Separation
Immunophenotyping
In Situ Hybridization, Fluorescence*
Pregnancy
Prenatal Diagnosis*