The impact of HLA-DR compatibility on cadaver kidney graft survival in a prospective study with special emphasis on the quality of typing.

The survival data of 151 consecutive cadaver kidneys transplanted by the two transplantation centres of Copenhagen from September 1, 1980 to September 30, 1982 with an observation period of at least 3 months have been analyzed. The HLA-DR types could not be established in 4 out of 130 donors. In most of the analyses only the well-defined antigens DR1, 2, 3, 4, 5, 7, and w8 were included. Inclusions of the DRw6, w9, and w10 antigens in the matching did not change the results. The one-year graft survival (GS) was 72.1% for 97 HLA-DR compatible kidneys as compared to 41.4% for 49 incompatible kidneys (p = .0007); this difference remained highly significant when stratified for the recipient status of pretransfusion, risk, and age. Non-transfused recipients had a fairly good GS but had received significantly better matched kidneys than the remaining recipients. The transfusion “effect” became barely significant (p = .054) when stratified for DR. There was no significant influence of donor or recipient DRw6-type as defined in this study. The GS was not significantly influenced by HLA-A, B matching, recipient antibody status, B cell cross-matches, transplant, or donor centre. Special efforts were made to assign the HLA-DR phenotypes of the recipients and donors as accurately as possible. In 39 cases, there was a discrepancy between the result of the acute DR-typing of the donor and the final result based on subsequent typings. The acute DR match had no influence on GS in these recipients whereas the final match had a significant influence in the same group, which in a way comprise a randomized trial. In the total material, the acute DR match still showed an influence on GS, but the significance decreased by a factor 20. This illustrates how the quality of DR typing may influence the results of the analyses. The overall GS (62.5%) was significantly (p = .05) better in this series than that (48.2%) in our preceding series, but it is uncertain whether this is due to better matching alone.