Acute renal failure in the transplanted kidney.

Acute renal failure (ARF) in the transplanted kidney represents a high-stakes area of nephrology and of transplantation practice. A correct diagnosis can lead to rapid return of renal function; an incorrect diagnosis can lead to loss of the graft and severe sequelae for the patient. The diagnostic possibilities are many (Fig. 10-1) and treatments quite different, although the clinical presentations of newonset functional renal impairment and of persistent nonfunctioning after transplant may be identical. In transplant-related ARF percutaneous kidney allograft biopsy is crucial in differentiating such diverse entities as acute rejection (Figs. 10-2 to 10-9), acute tubular necrosis (Figs. 10-10 to 10-14), cyclosporine toxicity (Figs. 10-15 and 10-16), posttransplant lymphoproliferative disorder (Fig. 10-17), and other, rarer, conditions. In the case of acute rejection, standardization of transplant biopsy interpretation and reporting is necessary to guide therapy and to establish an objective endpoint for clinical trials of new immunosuppressive agents. The Banff Classification of Renal Allograft Pathology [1] is an internationally accepted standard for the assessment of renal allograft biopsies sponsored by the International Society of Nephrology Commission of Acute Renal Failure. The classification had its origins in a meeting held in Banff, Alberta, in the Canadian Rockies, in August, 1991, where subsequent meetings have been held every 2 years. Hot topics likely to influence the Banff Classification of Renal Allograft Pathology in 1999 and beyond are shown in Figs. 10-17 to 10-19. Kim Solez Lorraine C. Racusen