The influence of HLA-A,B and -DR matching on leucocyte infiltration in renal allografts

The influence of donor and recipient HLA-A,B and -DR matching on the cellular infiltration in renal allografts was examined in 78 transplant recipients who received either cyclosporin (Cy) or azathioprine and low-dose prednisolone (AP) immuno-suppression. Transplant biopsies (n = 161) were routinely obtained up to 40 days after transplantation, and biopsy material was therefore available from both rejecting grafts and grafts with stable function. Tissue sections were labelled with a panel of monoclonal antibodies and stained using an indirect immunoperoxidase technique. Cellular infiltration was assessed using a morphometric point counting technique. In AP-treated patients with well-functioning grafts, poor HLA-AB and HLA-DR matching was associated with increased leucocyte infiltration, while in patients receiving Cy therapy the effect of matching on cellular infiltration was seen only during rejection in grafts poorly matched for HLA-AB antigens. In addition, where an effect of HLA-AB matching on cellular infiltration was found, CD8+, but not CD4+ cells, were significantly increased in number, while when an HLA-DR matching effect was seen, a significant increase was observed in the CD4+ and not the CD8+ infiltration. Thus, HLA matching may influence the magnitude of the cellular response in renal allografts and the phenotype of the infiltrating cells.