Comparison of different CD71 monoclonal antibodies for enrichment of fetal cells from maternal blood.

Different approaches have been proposed for the enrichment of fetal nucleated red blood cells (NRBC) from maternal blood as an alternative way to obtain fetal tissue for non-invasive prenatal diagnosis. The main purpose of this study was to compare two of our monoclonal antibodies (2E11.3 and 2B7.4 mAbs) with the most widely used commercial anti-CD71 mAb, in terms of their ability to isolate NRBC from maternal blood by magnetic activated cell sorting (MACS). Peripheral blood samples were obtained from 60 pregnant women at a mean gestational age of 16 weeks (range: 10-19 weeks). The number of NRBC isolated by our antibodies (median: 68, range: 0-2102) was significantly higher than that obtained by the commercial antibody (median: 38, range: 0-2165) in the same samples. However, in the final preparations, contamination by maternal nucleated blood cells was lower when the commercial antibody was used. Since fetal NRBC are rare in maternal blood, the improved NRBC recovery achieved by our non-commercial antibodies should facilitate the non-invasive detection of fetal aneuploidies in maternal blood.