[Kidney transplantation: what does biopsy contribute?].

Kidney biopsy is an important diagnostic tool for the evaluation of kidney transplantation. Histological evaluation of the donor kidney serves to identify risk factors for recurrent disease, neoplasia and/or graft failure due to numerous factors such as damage to the donor kidney during surgical removal or implantation, injury sustained during the transport process between the donor and recipient, and less than optimal allograft perfusion during the intra- and postoperative period. The most important question for the pathologist is the cause of renal dysfunction (rejection) after transplantation. The value of renal allograft biopsy has been significantly enhanced by several developments: improved, internationally accepted classification of kidney transplantation pathology (Banff 1997) and the development of molecular biological techniques such as RT-PCR evaluation of perforin, granzyme B and Fas ligand, which can be applied to renal allograft tissue to obtain a diagnosis of acute rejection with high sensitivity and specificity, are very promising but not used in routine diagnosis.