HLA-DR-MT matching improves graft survival rate in cadaver kidney transplantation. A prospective multicenter analysis of the South German Cooperative Study Group for Kidney Transplantation.

The influence of prospective HLA-DR matching on the graft survival rate was investigated in a multicenter analysis of 85 transplants. Simultaneously in a retrospective analysis of graft outcome the importance of matching for MT-antigens MT1, MT2 and MT3 as a newly defined B-cell alloantigen system was evaluated. HLA-DR antigens and MT-specificities were determined on B-cells enriched by nylon-wool filtration using locally well characterised HLA-DR antisera and the antiserum set of the 8th International Histocompatibility Workshop ("disease set") which allowed the definition of the HLA-DR specificities HLA-DR 1-9 and of the MT-antigens MT1-3. HLA-DR matching showed a significantly improved graft outcome only in HLA-DR identical donor-recipient combinations. In 11 of 60 patients with one HLA-DR compatibility additional matching for two MT-antigens, however, improved the two year graft survival rate from 60% to 91%. Altogether 17 patients were matched for two MT-specificities with their kidney donor and showed a superior prognosis of 94% at two years compared to 53% or 17% of recipients with one or zero MT compatibility. Graft outcome in this patient group was also superior to that of HLA-DR identical or HLA-AB identical grafts. These data suggested that the MT-system rather than the HLA-DR antigens may be of critical importance in cadaver kidney transplantation. In addition a favorable influence of pretransplant blood transfusions on less HLA-DR matched grafts was confirmed.