Absence of deleterious effect on long-term kidney graft survival of rejection episodes with complete functional recovery

Background. Rejection episodes (RE) exert a detrimental influence on long-term kidney graft outcome. However, the impact of the severity of those RE on graft survival and the factors that could predict this impact are ill defined, The present retrospective study was undertaken on adult patients who received 582 cadaver kidney transplants at our center during the last 12 years, to assess the impact on graft survival of RE occurring during the first year after transplantation and to uncover the factors associated with the severity of those RE. Methods. Three grades of rejection were defined: (1) rejection without loss of graft function (benign rejection); (2) rejection followed by partial loss of graft function (severe rejection); and (3) rejection with return to dialysis (irreversible rejection), The grafts were distributed among four groups: (1) grafts free of rejection; (2) grafts with benign RE (only grade 1 RE); (3) grafts with severe RE (one or more grade 2 RE); and (4) grafts with irreversible (grade 3) RE. Results. Multivariate analyses revealed that (1) the occurrence of RE during the first posttransplant year (group 1 versus groups 2, 3, and 4) was significantly associated with primary immunosuppression with CsA rather than with OKT3 monoclonal antibody, the number of HLA-B + DR mismatches, and the younger recipient's age; (2) in patients with rejection, OKT3 monoclonal antibody prophylaxis was less often used in patients with irreversible RE (group 4) than in those with reversible RE (group 2, benign, and group 3, severe); and (3) no single factor was able to differentiate patients with benign RE (group 2) from those with severe RE (group 3), For grafts still functioning 1 year after transplantation, long-term graft survival was similar in grafts with either no RE or benign RE, but it was significantly lower (P < 0.0001) in grafts with severe RE: 8-year survival rates were 89% and 60%, respectively, The decline in graft survival after 1 year was significantly correlated with the serum creatinine value but not with the dose of cyclosporine at 1 year. Conclusions. Benign RE occurring during the first year after transplantation and resulting in no loss of graft function do not exert a detrimental influence on long-term kidney graft outcome. In contrast, the prognosis of grafts with severe RE during the same period of time is much poorer.