Prenatal HLA typing of uncultured amniocytes prior to the collection of related allogeneic cord blood.

Abstract

DNA samples isolated from corresponding uncultured amniotic fluid, cord blood and maternal blood (n=5) were subjected to low resolution typing of the HLA-A, -B and -DRB loci by the polymerase chain reaction using sequence-specific primers (PCR-SSP). Furthermore, the effect of ethylene diamine tetraacetate disodium salt (EDTA) on the quality of genomic DNA isolated from amniotic fluid samples after long-term storage was evaluated. Unambiguous results of HLA typing could be achieved from all amniotic fluid samples stabilized with EDTA. PCR-SSP typing failed in DNA samples from amniotic fluid without the addition of EDTA. In all cases the fetal HLA type could be confirmed by the result from the corresponding cord blood typing. Contamination with maternal DNA led to additional weak PCR-SSP bands in one case, but data interpretation was still unambiguous. Reliable fetal HLA typing can be achieved directly from amniotic fluid and culturing of amniocytes is not required.