A special report: histocompatibility testing guidelines for hematopoietic stem cell transplantation using volunteer donors

The World Marrow Donor Association has formulated guidelines for establishi ng the extent and quality of histocompatibility testing for unrelated donor registries, umbilical cord blood banks, and transplant centers involved in international exchange of hematopoietic stern cells for allogeneic transpl antation. Registry and cord blood bank guidelines suggest that, at a minimu m, initial HLA typing should be performed for three HLA loci HLA-A, -B, and DR, at low resolution/split antigen level. DNA-based testing methods shoul d be utilized for HLA-DR typing. DNA-based testing for HLA-A and -B should replace serologic testing of new volunteer donors and cord blood units as r obust protocols and reagents become available to the laboratories. Transpla nt center guidelines for typing of patient, family and to confirm the HLA t ypes of potential unrelated donors should include, at the minimum, typing H LA-A, B, and -DR loci using primarily DNA based testing methods at allele l evel resolution for DRB1 and low resolution/split antigen level for HLA-A a nd -B. It is strongly recommended that the typing of a patient and the sele cted donor be performed using the same set of reagents, methodology, and in terpretation criteria with fresh tissue samples to ensure HLA identity Guid elines for laboratory accreditation, approaches to quality assurance and qu ality control for HLA testing, and suggestions for the format of the HLA da tabase of donor types are also outlined.