Defining delayed graft function after renal transplantation: simplest is best

Area of Science:

• Nephrology and Transplant Surgery
• Medical Research Methodology

Background:

• Delayed graft function (DGF) is a common complication in renal transplantation.
• Inconsistent definitions of DGF hinder comparative analysis of transplant outcomes.
• This issue is particularly relevant for donation after circulatory death (DCD) kidney transplants due to high DGF incidence.

Purpose of the Study:

• To evaluate the impact of various DGF definitions on renal transplant outcomes.
• To compare the association of DGF with graft function and survival across different definitions.
• To determine the optimal definition of DGF for clinical use and research endpoints.

Main Methods:

• Retrospective analysis of 213 donation after brain death (DBD) and 312 DCD kidney transplants.
• Assessed DGF using 10 different definitions based on dialysis or creatinine criteria.
• Correlated DGF occurrence with 1-year estimated glomerular filtration rate (eGFR) and graft survival.

Main Results:

• DGF incidence varied significantly (DBD: 24%-70%; DCD: 41%-91%) based on definition.
• For DCD kidneys, DGF definition inconsistently predicted poorer 1-year eGFR and did not impact graft survival.
• For DBD kidneys, most DGF definitions predicted poorer 1-year eGFR and inferior graft survival, with comparable predictive power across definitions.

Conclusions:

• No single definition of DGF is universally superior.
• The definition based on dialysis requirement in the first postoperative week is proposed for universal adoption.
• Standardizing DGF definition will improve clinical practice and research comparability in kidney transplantation.