- The recipient has an unrelated donor who with high resolution typing is either fully MHC matched at HLA-A, B, C and DRB1 with the recipient or is 1-antigen or 1-allele mismatched at A, B, C or DRB1 loci The recipient meets the transplant centre's criteria for unrelated donor allogeneic transplantation , either myeloablative or non-myeloablative (syn. RIC).