HLA-DR typing of organ donors and allograft recipients by SSO typing: correlation with serotyping in the North Italy Transplant Program

Comparison of serological and molecular typing for HLA-A and -B on cord blood lymphocytes

HLA class I typing by standard microcytotoxicity testing has been unsatisfactory for 14.5% of 1644 cord blood samples. In this study, we evaluated the capacity of PCR-SSP in solving problems in HLA-A,B typing with serological methods. With this aim we have compared serology with PCR-SSP in 100 cord blood samples with doubtful or unreliable HLA-A,B typing. PCR-SSP was successful in amplifying HLA-A,B alleles in all 100 cord blood samples. Forty-six typings gave discrepant results with the 2 methods (serology and PCR-SSP). Typings were considered discrepant also in the case of inability to define a split. For 19 specimens, no serological conclusion was drawn due to high mortality of the cell suspension, while PCR-SSP allowed the definition of a clear typing. In 6 cases it was necessary to infer information from serology to define the current typing. Finally, in 3 other cases it was impossible to exclude or attribute the antigen/allele B67 or B4802. PCR-SSP for HLA-A,B can improve the overall reliability of HLA-A,B typing requiring a small amount of blood although, with the set of sequence specific primers adopted, a number of alleles are still poorly defined.

HLA-DRB1 compatibility in cadaver kidney transplantation: correlation with graft survival and function

The introduction of genomic HLA-DR typing has stimulated a re-evaluation of the role of HLA-DR compatibility on cadaver kidney transplantation. We retrospectively studied the influence of HLA-DRB1 matching on the survival of 416 patients using univariate and Cox regression analysis as well as its influence on the occurrence of rejection episodes and on creatinine level at the 3rd month in the 198 recipients for whom these data were available. The following parameters were also considered: HLA-A,B compatibility, donor and recipient age, graft number, pre-transplant blood transfusions and panel reactive antibodies (PRA). Twenty-four month graft survival was 100% for transplants with zero mismatches (n = 47), 87.9% for those with one mismatch (n = 191) and 81.3% for those with two mismatches (n = 178). In the Cox model, HLA-DRB1 matching was the most significant variable influencing graft survival (47% of chi 2 P = 0.001), followed by HLA-A,B matching (23%, P = 0.02) and donor age (19%, P = 0.04). Ninety-two percent of the patients with zero mismatches experienced no rejection episodes in the first 3 posttransplant months compared with 62% and 41% of patients with one and two mismatches, respectively. Mean creatinine level (mg/dl) was 1.2, 1.4, and 1.5 in patients with zero, one, and two mismatches, respectively. Should these results be confirmed by prospective studies, HLA-DRB1 compatibility will have to be considered as an organ allocation criterion.