Efficacy endpoints conference on acute rejection in kidney transplantation: Summary report of the database

An international database of rejection episodes and their characteristics with regard to definition and follow-up parameters was developed to improve the approach to protocol development for clinical trials. Nineteen North American, European, and Australian centers uniformly reported on 50 consecutive transplant rejection episodes. Data collected included patient demographic parameters, induction and maintenance immunosuppression therapies, rejection agents (drug, dose, duration), clinical signs (50% decrease in urine, fever), serum creatinine (nadir, at rejection, dally during antirejection therapy to 15 days, and days 30, 90, 180, and 365 after rejection date), histopathological findings, morbidity, recurrence of rejection, and function at 1 year. The centers contributed a total of 953 presumed rejection episodes, of which 842 were confirmed as acute rejection episodes. The majority of cases were first rejections (81%), and rejection occurred 119 ± 345 days following transplantation. The Banff Schema of histological grading was used in 38% of biopsy-proven rejection episodes (2% Borderline, 42% Grade I, 38% Grade II, 18% Grade III). Only 30% of all rejections showed clinical signs that were most likely to occur in Grade III rejection episodes (P < 0.006). The serum creatinine response was well below the rejection creatinine level by day 15 following initiation of antirejection therapy in the majority of cases. A significant number of the cases (34%) reported in this database experienced a recurrent rejection approximately 85 days following the first rejection. Graft survival I year following the rejection episode was good (83%). These findings will facilitate development of clinical trial design and beneficially impact approaches to antirejection therapies for kidney allograft recipients.