Graft quality assessment in kidney transplantation: not an exact science yet!

The enduring donor shortage necessitates the development of tools capable of objectively assessing kidney graft quality and thereby allowing the safer and wider use of expanded criteria donors and kidneys donated after cardiac death. We summarize current assessment tools available prior to procurement and during preservation.

Several donor risk scores, combining donor and recipient risk factors of inferior graft outcome, exist but all lack predictive power. Histological scoring of glomerulosclerosis, tubular atrophy, interstitial fibrosis, and vascular damage in pretransplantation kidney biopsies can supply reliable, reproducible data on the actual kidney state but prospective data on their use in graft assessment are lacking. Renal resistance and certain perfusate biomarker concentrations during machine perfusion are independent risk factors of delayed graft function, but neither method has sufficient predictive power to allow kidney discard.

Available tools for graft quality assessment have their intrinsic value but none offer the necessary power to predict graft outcome for a specific donor-recipient pair. This is probably due to the multitude of donor, preservation, and recipient factors at stake. Only combining these factors might improve prediction of graft outcome and allow safer use of expanded criteria donors and kidneys donated after cardiac death.