569 Proenkephalin A 119-159 (penKid) for the early identification and risk stratification of delayed graft function following kidney transplantation

Abstract Background and Aims Delayed graft function (DGF) frequently occurs following kidney transplantation, and prolonged duration of DGF adversely affects 1-year graft function and long-term graft survival. Recently, Proenkephalin A 119-159 (penKid) was shown to reflect kidney function and predict acute kidney injury (AKI) in critically ill patients. Given the similarities between DGF in transplanted and AKI in native kidneys, we hypothesized that penKid may aid in identifying and risk-stratifying DGF post-transplantation. Method In a prospective study of 159 consecutive kidney transplant recipients at Heidelberg University Hospital from November 2021 to July 2023, penKid was quantified using an immunoluminometric assay until patient discharge. DGF was primarily defined as the necessity for dialysis within 7 days post-transplant. Additionally, penKid was examined in the context of DGF severity, discriminating the different durations of post-transplant dialysis treatment. Similarly, penKid was assessed to differentiate uptake of graft function, defined as slow or immediate by a serum creatinine reduction ratio of pre-transplant and 7 days post-transplant levels of