The search for HLA-compatible bone marrow donors. Procedure currently used in the Institute of Hematology and Blood Transfusion, Prague.

The search for compatible donors is based on the HLA types of donors and recipients. HLA-A, -B and -DRB1 antigens or alleles must be unequivocally typed in donors and recipients. The typing of HLA-DQB, -DPB and -C gene products is also useful to characterize the HLA phenotype, but it is not absolutely necessary in the donor selection. The standard serological methods using alloantisera and one-dimensional isoelectric focusing are used for the typing of HLA class I antigens. Recently, DNA analysis of class I alleles has been introduced. In HLA class II typing the serological analysis was generally replaced by DNA analysis. In addition to typing techniques that determine the individual HLA alleles or HLA gene products, the cellular matching techniques are used in the selection procedure (mixed lymphocyte culture, cytotoxic T lymphocyte precursor frequency assay, and IL-2-producing helper T lymphocyte precursor frequency assay). The cellular matching techniques determine the compatibility in the regions of HLA comprising several HLA loci; some of them may detect minor histocompatibility (non-HLA) gene disparities as well.