Calculated PRA and PIRCHE Algorithm in Kidney Transplant Recipients

Calculated PRA testing in kidney transplantation has revolutionized the field by enabling a more accurate assessment of compatibility and risk prediction for AMR. On the other hand, The PIRCHE algorithm aims to identify the potentially immunogenic human leukocyte antigens (HLA) epitopes on the donor graft that are recognized by the recipient's HLA antibodies.The aim of this analysis was to compare the actual immunological risk at the time of transplantation with the hypothetical risk that would be determined by cPRA and PIRCHE. Another aim was to compare this hypothetical risk also in the context of the development of DSA and the protocol graft biopsy at month 3.In a group of 20 patients we recorded the real immunological risk determined at the time of transplantation according to the induction immunosuppression protocol of the Transplant-Nephrology Department of the University Hospital Martin and compared it with the hypothetical calculated risk according to cPRA and PIRCHE. We then compared the hypothetical risk with the protocol biopsy result and with any evidence of donor-specific antibodies at month 3 after the kidney transplantation.Under cPRA, the two patients we assessed as medium risk in real time would be classified as low risk. Both of these patients did not have DSA identified at month 3 and did not have rejection changes in the protocol biopsy. According to PIRCHE, the immunological risk would change from moderate to low in two patients, and even from very high to low in one patient. In none of these patients did we subsequently observe DSA formation at month 3 post-transplantation, and also all three protocol biopsies were free of rejection changes in these patients.In our analysis we confirmed the importance of both immunological and non-immunological parameters for determining risk at the time of transplantation. For using PIRCHE score larger studies are required to confirm this strategy.