Biopsy of the transplanted kidney--role of protocol biopsies.

Traditionally, renal allograft biopsies were performed mainly in the setting of acute graft dysfunction. Recently, there has been a change of paradigms. Several reports suggested that acute rejection of the graft and chronic allograft nephropathy are often subclinical without any deterioration in the graft function. This raises the issue of biopsies in functionally stable allografts (e.g. protocol biopsies) and the clinically useful information they provide. Namely, recent reports provide evidence in favour of treating biopsy-proven subclinical rejections. Moreover, by early identification of chronic histological lesions, protocol biopsies give an opportunity for individualized immunosuppressive regimen and use of targeted therapeutic strategies, in order to prevent chronic allograft dysfunction and improve long-term graft outcome. In this review, diagnostic, therapeutic and research benefit information on protocol biopsies performed in stable kidney recipients are described.