Use of endocervical trophoblasts in noninvasive prenatal testing for common aneuploidies

Abstract

The article presents an experience of isolation of trophoblast cells from cervical samples of pregnant women and demonstrates a possibility of determining aneuploid cells in cervical samples using FISH analysis. Objective. To study methods of effective isolation and reliable detection of trophoblasts for genetic pathology analysis. Patients and methods. The participants of the study were three pregnant women, who according to the findings of the combined first trimester screening test were referred to the group with a high risk for fetal aneuploidy. The terms of gestation varied from 12 to 14 wks. Immunocytochemical detection of trophoblast cells was performed with FITC-labelled HLA-G antibodies. FISH was performed with the use of locus-specific DNA probes on chromosomes 13/21 and a DNA probe on chromosome 18 centromere. The chromosome set of a fetus was verified by the results of standard cytogenetic analysis of semi-direct chromosome preparations from cytotrophoblast cells obtained by chorionic villi biopsy. Results. HLA-G-positive cells were found in all examined cytological specimens. FISH analysis with the use of DNA probes on chronomomes, whose trisomies are compatible with live birth, detected aneuploid cells in all three cases. Conclusion. The use of cervical trophoblasts for noninvasive collection of information about the genetic status of the developing fetus at present needs further study of effective and reliable methods of their isolation, detection and analysis. Key words: aneuploidy, throphoblast cells, NIPT, prenatal diagnosis, HLA-G