A novel approach for the in vivo isolation of fetal cells directly from the maternal circulation for prenatal diagnostics using a functionalized structured medical wire (FSMW)

Abstract

The prenatal diagnosis of chromosomal defects gains in importance due to the fact, that the average maternal age increases and therefore the risk of chromosomal aberrations. In the presented approach, a functionalized and structured medical wire (FSMW) was developed for the in vivo isolation of fetal trophoblasts directly from the maternal circulation. The FSMW was coated with human or murine antibodies directed against the HLA-G-antigen, which is highly expressed on the surface of fetal trophoblasts. The safety of the FSMW was tested with 18 (6+12) healthy non-pregnant female volunteers in two studies with different antibodies. Subsequently, 36 (24+12) healthy pregnant subjects participated in the study with the FSMW. The medical wire was inserted through a standard venous cannula into the cubital vein for 30 to 45 minutes. After removal of the FSMW trophoblasts were identified by PCR or immunocytochemical staining and subsequent counting under a fluorescence microscope. The FSMW showed very good biocompatibility and no side effects in all healthy volunteers and all pregnant subjects. After the application of the detector functionalized with the murine antibody no human anti-mouse antibodies (HAMAs) were detected in all 24 participating non-pregnant and pregnant women. The detection of male fetal cells on the FSMW was accomplished by PCR.