Ten-year protocol biopsy findings of renal allografts in the calcineurin inhibitor era.

Ten-year protocol biopsies were performed in 16 patients treated with calcineurin inhibitor (CNI) continuously. All kidney grafts were functioning well at the time of biopsy with the mean serum creatinine level of 1.6 +/- 0.8 mg/dL. The specimen of biopsy showed various degrees of tissue injury. According to the Banff grading, allograft glomerulopathy (cg) was observed in one case. Interstitial fibrosis (ci) and tubular atrophy (ct) were observed more frequently in 13 (81%) and 15 (93%) cases, respectively. Fibrous intimal thickening (cv) was seen in one (7%) case. Arteriolar hyaline thickening (ah) was seen in 14 (87%) cases. These findings were associated with chronic rejection in one case, recurrence of original disease in four (25%) cases, toxicity of CNI in 14 (87%) cases. Longer follow-up studies are needed to confirm whether CNI should be continued or not in the long-term period following kidney transplantation for better graft survival.