PROTOCOL RENAL ALLOGRAFT BIOPSIES AND THE DESIGN OF CLINICAL TRIALS AIMED TO PREVENT OR TREAT CHRONIC ALLOGRAFT NEPHROPATHY1

BACKGROUND The minimum sample size to perform a clinical trial aimed to modify the natural history of chronic allograft nephropathy (CAN) is very large. Since the presence of chronic tubulointerstitial damage in renal protocol biopsy specimens is an independent predictor of late outcome, we evaluated whether protocol biopsies could facilitate the design of trials aimed to prevent or treat CAN. METHODS Two hundred eighty-two protocol biopsy specimens were obtained 3 months after transplantation in 280 patients with serum creatinine levels