HLA Matching, Blood Transfusion and Renal Transplantation

Analysis from the Eurotransplant data base reveals that matching for HLA-A and -B antigens has a beneficial effect not only on cadaveric kidney graft survival but also on patient survival. This beneficial effect can be demonstrated most clearly after five years follow-up time with a sufficient number of donor-recipient combinations in the various HLA-A and -B mismatch categories.

Matching for the HLA-DR determinants also improves kidney graft survival significantly. The best kidney graft survival is obtained when donor and recipient are matched for the HLA-DR determinants as well as for the HLA-A and -B antigens.

Concerning pretransplant blood transfusions, it is unequivocally clear from the prospective study in The Netherlands that one leucocyte-poor blood transfusion is a good pretransplant blood transfusion protocol. Furthermore, transfusions which are depleted of leucocytes, i.e. leucocyte-free blood, do not improve kidney graft survival.

The interaction between the two important factors, HLA-matching and pretransplant blood transfusion, shows that HLA-A and -B matching as well as HLA-DR matching is most apparent in non-transfused recipients, although it should be stressed that the best kidney graft survival is obtained when donor and recipient are well matched for HLA and the recipient has been transfused.

In an attempt to identify patients before transplantation in high or low responders, it can be shown that typing for HLA-DRw6 antigen can be helpful in this respect. HLA-DRw6 positive patients are high responders and should be transplanted with HLA-DRw6 positive kidneys. Furthermore, it can be demonstrated that HLA-DRw6 positive donor kidneys have a better than average graft survival, independent of the match. Good kidney graft survival was obtained with such donors even in the face of one or two HLA-DR mismatches (see Table 8).

In conclusion, the role of HLA-A, -B and -DR matching was, and still is, a very important factor in kidney graft survival. However, they are certainly not the only factors at play. Others, such as clinical management, immunosuppressive treatment, warm ischaemia time, monitoring of T-cell subset ratios, etc., should be considered as well in further analyses (van Es et al, 1983). Predicting renal allograft survival remains extremely difficult, as it is dependent on a multitude of interacting factors.