Relevance of complotyping and subtyping of MHC class I gene products in haplotype definition for allogeneic bone marrow transplantation.

In preparation for a bone marrow transplantation 217 patients and their families were complotyped for Bf, C4A and C4B in addition to the routinely performed HLA-A,B,C,DR and HLA-D typing. In 147 families uncertainties in haplotype definition occurred which could be solved in 37 cases (25%) by complotyping. Additionally, patients and their relatives were subtyped for class I gene products by one-dimensional isoelectric focusing, a method by which serologically identical HLA-A, B, or C antigens could be split in five out of 22 cases tested. The results obtained clearly show the relevance of both methodologies for finding the best match of donor/recipient pairs to help to prevent MHC-induced graft-versus-host disease after bone marrow transplantation.