MOLECULAR ANALYSIS OF HLA GENES FOR THE SELECTION OF UNRELATED BONE-MARROW DONOR

The selection of fully matched unrelated volunteer donors (UVD) in BMT requires a molecular characterization of MHC polymorphism, since most phenotypically HLA-identical donors can be non-identical when analyze d at a genomic level, The present report describes a molecular typing protocol for HLA genes developed for the selection of UVD, and its app lication to some donor-recipient pairs, The protocol involves three su ccessive steps, Firstly, PCR with sequence-specific primers for HLA-DR B1 and -DQB1 genes is performed to identify the major alleles of the r ecipient, PCR-fingerprint matching is then introduced for HLA-A, B, C and DRB, DQB and DPB genes to screen prospective donors. Those showing matched fingerprinting patterns are finally submitted to direct seque ncing of the DRB1 gene, DPB compatibility is assessed by oligotyping w hen there are several potential class I and DRB matched donors, This s trategy was applied retrospectively to three BMT recipients and their previously selected donors. Three other patients and their 12 prospect ive donors were submitted to our protocol before BMT, Clinical evaluat ion of transplant outcomes indicates the primary importance of complet e DRB and class I matching; while DQB and DPB compatibility seems to b e less critical.