Defining delayed graft function after renal transplantation: simplest is best.
BACKGROUND
Delayed graft function (DGF) after renal transplantation can be diagnosed according to several different definitions, complicating comparison between studies that use DGF as an endpoint. This is a particular problem after transplantation with kidneys from donation after circulatory death (DCD) kidneys, because DGF is common, and its relationship to early graft failure may differ depending on the definition of DGF.


METHODS
The presence of DGF in 213 donation after brain death (DBD) and 312 DCD kidney transplants from October 2005 to August 2011 was determined according to 10 different, but widely used, definitions (based on dialysis requirements, creatinine changes, or both). The relationship of DGF to graft function and graft survival was determined.


RESULTS
The incidence of DGF varied widely depending on the definition used (DBD; 24%-70%: DCD; 41%-91%). For kidneys from DCD donors, development of DGF was only associated with poorer 1-year estimated glomerular filtration rate for 1 of 10 definitions of DGF, and no definition of DGF was associated with impaired graft survival. Conversely, for DBD kidneys, DGF, as defined in 9 of 10 different ways, was associated with poorer 1-year estimated glomerular filtration rate and inferior graft survival. Importantly, the predictive power for poorer transplant outcome was comparable for all definitions of DGF.


CONCLUSIONS
No definition of DGF is superior. We suggest that the most widely used and most easily calculated definition--the use of dialysis in the first postoperative week--should be universally adopted as the definition of DGF clinically and as a study endpoint.
1 Department of Surgery, Addenbrooke's Hospital, Cambridge, UK. 2 Address correspondence to: Dermot H. Mallon, Department of Surgery, Addenbrooke's Hospital, Box 202, Cambridge CB2 0QQ, UK.
Dermot H
DH
Mallon
Dominic M
DM
Summers
J Andrew
JA
Bradley
Gavin J
GJ
Pettigrew
D000328:Adult; D051799:Delayed Graft Function / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D015994:Incidence; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D009927:Tissue and Organ Procurement / Q000379:methods*; D006113:United Kingdom / Q000453:epidemiology