Acute rejection episodes – Best predictor of long‐term primary cadaveric renal transplant survival

Uniformly high 1‐year primary cadaveric renal transplant survival has prompted an interest in establishing clinical factors associated with longer‐term (i.e., more than 5‐year) graft survival. We have studied 665 consecutive primary transplanted cadaveric kidneys using sequential quadruple immunosuppression with at least 1 year of follow‐up (average 41.4 months). No attempt at HLA matching was made and all rejection episodes were confirmed by histology. Overall, 8‐year patient and graft survival were 78% and 60%, respectively. Death as a cause of graft loss occurred in 103 patients. However, only 14 patients died from complications of immunosuppression. A multivariate analysis was performed using age, sex, blood type, race, presence of diabetes, HLA mismatch, current and maximum panel reactive antibody (PRA), time to first rejection episode, treatment of first rejection episode, and number of rejection episodes (none, one, or more than one). Number of rejection episodes was by far the most important co‐variate (p= <0.00001). In total, 53% of patients had no rejection episodes, 25% had one, and 22% had more than one. The occurrence of acute rejection did not correlate with the degree of HLA mismatch or PRA. Demographic and immunologic variables were similar for all three groups. Actuarial 8‐year graft survival was negatively affected by rejection history (Fig. 1). Uncensored T2 in the group with no rejection episodes was 16.9 years, compared with 3.9 years in the group that experienced more than one such episode. In conclusion, the predominant factor to dictate long‐term CAD kidney graft survival is the presence or absence of one or more rejection episodes early in the post‐transplant course. These data suggest that chronic rejection occurs almost exclusively in patients successfully treated at one or more time points for acute rejection.