Male DNA in female donor apheresis and CD34-enriched products.

Increased risk of graft-versus-host disease (GVHD) has been described in recipients of hematopoietic stem cell transplantations when the donor is a parous woman. Cells from prior pregnancies are now known to persist in women and could contribute to GVHD. We asked whether male DNA (presumed fetal microchimerism) is present in apheresis products of female donors. A total of 50 samples were studied by using real-time quantitative polymerase chain reaction (PCR) for the Y chromosome-specific sequence DYS14. Among 29 growth factor-mobilized peripheral blood mononuclear cell (G-PBMC) products, 34% were positive for male DNA. Quantitative results, expressed as DNA genome equivalent of male cells per million host cells (gEq/mil), ranged from 0 to 35 gEq/mil. Among 21 CD34-enriched cell fractions, 48% were positive with a range of 0 to 357 gEq/mil. In summary, male DNA was frequently detected in G-PBMC and CD34-enriched products from female donors. Whether fetal microchimerism contributes to GVHD merits further investigation.