Immunological risk in recipients of kidney transplants from extended criteria donors

Background. Determining if a kidney from a marginal donor is likely to elicit a strong and specific immune response, leading to an increased risk of acute rejection, is of importance in renal transplantation. Methods. In this study, we analysed the effect of extended criteria donor (ECD) on the incidence of biopsy-proven acute rejection (BPAR) and the effect of immunological risk factors on graft outcome in a large cohort of kidney transplant recipients (n = 2121 patients) grafted with ECD (n = 656 patients) or optimal donor (OD) (n = 1465 patients). Results. The incidence of BPAR was not statistically different between the ECD group recipients (105/656, 16%) and the OD group recipients (251/1465, 17%) (P = 0.52). These values remained similar after adjustment for immunological risk [defined as retransplantation and/or panel-reactive antibody (PRA) level >20%] (P = 0.92 for patients with immunological risk and P = 0.47 for patients without immunological risk). We next analysed the death-censored graft survival data for OD and ECD groups, as a function of immunological status, and found that the immunological risk factor did not affect graft survival in ECD transplant recipients (P = 0.64). Conclusion. Although our groups were not homogenous, our study did not reveal an increased risk of acute rejection in recipients of ECD allograft.