Method dependency of blood group determination after bone marrow transplantation.

After minor-incompatible bone marrow transplantation (e.g. recipient A, donor 0), red cells are donor-type but absorb recipient-type AB0 substance from plasma. Because of discrepant results, we tested how such cells type with standard methods. In the tube test 7 of 8 patients showed donor type. In Diamed AB0 gel, weak-positive reactions were found with anti-AB in the patients (donor 0) tested. Commercial AB0 antibodies from different companies used in Diamed neutral gel trays differed widely in the results obtained. The strongest positive reactions were found with polyclonal anti-AB. The exact antibody and technique are crucial to the result of AB0 typing after minor-incompatible bone marrow transplantation.