In our study we investigated the cellular alloimmunity of kidney allograft recipients using direct interferon (IFN)-g enzyme-linked immunospot assay (ELISPOT). Donor splenocytes PBMC of 53 recipients were obtained alongside kidney recovery. 11 recipients presented positive pre-transplant PRA values. For ELISPOT data analysis we calculated number, size and intensity of the spots, which reflected the volume of cytokine secretion at the single cell level. The results were recalculated as the ratios of the values observed for donor stimulated and unstimulated recipient cells and corrected for residual donor activity. Significantly higher pre-transplant donor stimulated activity was observed for the recipients who underwent AR episode within one year after Tx (p<0.05). The mean change in the spot number, size and intensity observed for rejectors vs. nonrejectors were 0.99 vs. 3.33, 1.6 vs. 6.05, and 1.4 vs. 6.31, respectively. The assessed parameters were prognostic of high AR risk - 1.5-fold increase in spot number (AR incidence 9% vs. 52%), 2.0-fold increase in size (AR incidence 11% vs. 44%), and 2.7-fold increase in intensity (AR incidence 9% vs. 52%). The three parameters analyzed were correlated with the one year serum creatinine concentration (p<0.05). From 14 AR positive recipients, 11 could have been predicted with pre-transplant ELISPOT measures, while only 2 based upon PRA values. Our data show that the ELISPOT determined volume of donor induced activity observed for the recipient cells obtained just before Tx is predictive of the risk of graft rejection and one-year term graft function.

Keywords: Kidney Transplantation