Major effects of delayed graft function and cold ischaemia time on renal allograft survival

Background. There is mounting evidence from experimental and clinical studies that the quality of organs from cadaver donors may be influenced by events occurring around the time of brain death, and that these may affect transplant outcome. The aim of this study is to investigate the influence of donor factors on renal allograft outcome in a homogeneous cohort of 518 patients transplanted in a single centre over a 9 year period. Methods. Endpoints of the study were delayed graft function (DGF), acute rejection (AR), 1 year graft survival and long-term survival of those grafts that reached 1 year. Multivariate analysis was performed to determine factors that may have influenced the graft outcome indicators. Results: DGF was the major predictor of graft failure overall with cold ischaemia time (CIT) as an important independent factor. The level of histocompatibility did not influence graft survival. DGF was the major factor affecting 1 year graft survival ( P < 0.0005) with effects persisting beyond 1 year. DGF was significantly influenced by CIT, donor age, female kidney into male recipient and donor creatinine (P < 0.05). Other donor factors and factors associated with donor management were not risk factors for DGF, rejection episodes or graft survival. The risk factors for a number of AR episodes were HLA - DR mismatch and DGF ( P < 0.005). When grafts surviving for 1 year were considered, only CIT, recipient age and creatinine at 1 year ( P < 0.05) were found to affect graft survival significantly. Conclusions. The results of this analysis of well-matched transplant recipients show that CIT and DGF are the most important predictors of poor short and long-term graft survival. Therefore, in order to improve the long-term survival of renal allografts efforts should focus on limiting CIT and the damage that occurs during this period and on improving our understanding of DGF.