Evolution of Rejection Rates and Kidney Graft Survival: A Historical Analysis

Introduction. New immunosuppressive regimens have dramatically reduced rejection rates but this positive effect has not been followed by an improvement in long-term graft outcomes. The aim of the present work was to investigate the incidence of graft rejection and graft outcomes with various immunosuppressive protocols. Patients and Methods. Included in our study were 1.029 first renal transplantations performed at our unit between November 1979 and December 2007. Basal immunosuppression included azathioprine (AZA) in 198 recipients, cyclosporine (CsA) in 524 recipients, and tacrolimus (TAC) in 307 recipients. Results. Recipient and donor ages increased progressively from the AZA to the TAC era. Delayed graft function was less frequent among AZA than CsA and TAC recipients (29.8 vs 39.3% vs 42.0%; P = .014). The incidence of acute rejection episodes was 68.7% on AZA, 38.2% on CsA, and 11.4% on TAC (P = .000). Graft survival rates at 1, 5, and 10 years were 69%, 56%, and 46% on AZA, 82%, 69%, and 54% on CsA, and 88%, 77%, and 60% on TAC, respectively (P = 001). However, the differences disappeared when only grafts surviving >12 months were analyzed. On multivariate analysis, the variables associated with worse graft outcomes after 12 months were older recipient age, male gender, longer time on dialysis, lower body weight, and higher serum creatinine level at 6 months. Conclusions. New immunosuppressants have decreased the incidence of acute rejection. But this was not followed by a significant improvement in graft outcomes after 12 months. The beneficial effects on rejection are possibly affected by the older age of donor and recipient and the worse early graft function.