Long-term graft outcome is not necessarily affected by delayed onset of graft function and early acute rejection

Both acute rejection episodes and delayed graft function (DGF) have been shown to be associated with decreased 1-year renal allograft survival. In our center, the incidence and the intensity of acute rejection episodes have been reduced by cyclosporine-based triple-drug therapy. We have also shown that DGF alone is not a risk factor for long-term graft survival.

We have now investigated whether an acute rejection episode together with DGF significantly effects long-term graft outcome. This study involved 862 first cadaveric renal allografts and 182 regrafts.

The incidence of DGF was 33% after first transplants and 44% after retransplants. The overall incidence of acute rejection episodes was 23% in first grafts and 28% in regrafts. After first grafts, there were no statistically significant differences in graft survival rates and half-lives between the early graft function (EGF) and DGF groups with or without acute rejection. In regrafts, graft survival was significantly higher in the EGF group without acute rejection than in the DGF group with acute rejection. However, if all other causes except chronic rejection were censored, the half-life in the EGF group without acute rejection was 17.3 years in first grafts, and in the DGF group with acute rejection, that number was 11.5 years in first grafts; for regrafts, the half-life was 12.3 years and 6.1 years, respectively.

Acute rejection together with DGF could contribute to initial damage to the graft, and this might lead to later chronic allograft failure. In our study, this effect was evident only in the case of retransplants.