Short-Term and Long-Term Effects of Delayed Graft Function (DGF) on Graft Survival in Pediatric Renal Transplantation

Delayed graft function(DGF) generally refers to oliguria or the requirement for dialysis in the first week post-transplantation. It is the earliest and most frequent post- transplantation complication that can occur. DGF is an extremely important post- transplantation complication because its occurrence has short-term or long-term consequences for allograft survival. However, limited studies have been conducted on DGF and its complications in pediatric renal transplantation. Therefore, the aim of the present study was to determine short-term and long-term effects of DGF on allograft outcome in kidney transplanted children. Patients and In this historical cohort study, 230 children who received kidney transplants between 1985 and 2005 in Labafi Nejad Hospital in Tehran were assessed through a mean follow-up period of 60.96(SD=40.46) months (ranging from 1 to 180 months). The children were divided into two groups: 183 children in group B(no DGF) as the control group and 47 patients in group A (DGF) as the case group. Risk factors of DGF and the impact of DGF on renal function within the first year, long-term graft survival, and post-transplantation complications were investigated and compared using Logistic regression model and Kaplan–Meier survival analysis. The incidence of graft failure at the end of follow-up period was significantly higher in DGF group(53.2% vs. 22.4%, P<0.001). The mean graft survival length was 134.2(SEM=6.17) months in group B and 76.52(SEM=12.41) months in group A(P<0.001). The graft survival rate was 94.9%, 91.9%, 83.9%, 79.2% and 72% at 1, 3, 5, 7 and 12 years after transplantation in children without DGF versus 75.6%, 53.2%, 47.2%, 31.9% at 1, 3, 5 and 8 years after transplantation in patients with DGF. Dialysis before transplantation(P=0.039), acute rejection(P<0.001), immunosuppressive protocol without celcept(P<0.001) and the presence of DGF(P<0.001) were found as the significant risk factors for the occurrence of graft failure in the future. The results of our study showed that delayed graft function could remarkably and independently affect graft survival and worsen both short-term and long-term transplantation outcomes. This result is in contrast with the studies that only believe in the effect of DGF on short-term graft survival. However, in our study when patients whose grafts had failed during the first year after transplantation were censored, still significant differences were noted in graft survival between patients with and without DGF. Thus, the prevention of DGF is one of the most important issues in graft survival improvement.