[HLA-amino acid residue matching standard and immunogenic response]

To provide a standard for HLA-amino acid residue matching (Res M) for Chinese population and to evaluate its immunogenic response and sensitization to allograft.

Based on the setting up of DNA typing technique and the analysis of the distribution of HLA antigen frequencies, a new matching policy of Res M of 17 residues (10 amino acid residues for class I and 7 DR supertypic groups for class II) was presented and prospectively applied to 163 first-cadaver kidney transplants. Comparing with the 6-antigen matching program, the immunogenic response and sensitization of Res M to allograft were assayed using the mixed lymphocyte culture (MLC), cytokine in culture liquid, immune competent cells in the peripheral blood and specific anti-HLA IgG antibodies with PRA-STAT technique.

The rate of Res-matched transplants increased significantly from 1.2% by Ag M to 39.9%. Immunogenic response and sensitization to allograft of recipients with Res-matched, containing index of stimulation (SI) of MLC, gamma-IFN representing Th1 cell, IL-10 representing Th2 cell, CD4+, CD8+, CD28+ T cell and the ratio of CD4/CD8, as well as the level of sHLA-IgG representing sensitization to allograft, were similar to those of Ag-matched transplants. Those parameters showed no difference between Res-matched and Ag-matched recipients, but showed significant difference in Res-mismatched or Ag-mismatched transplants.

The New Res M can increase the rate of Res-matched transplants by a big margin, minimize the sensitization and immunogenic response to allograft, and be suitable to the clinical application to organ transplantation in Chinese Han population.