Pathology of recurrent diseases in kidney allografts: membranous nephropathy and focal segmental glomerulosclerosis.

PURPOSE OF REVIEW: Glomerulonephritis is the leading cause of end-stage renal failure in renal transplant recipients. Recurrence of diseases in kidney allograft provides a unique opportunity to study the mechanisms of kidney disorders leading to the underlying native organ failure. There have been new advances in the understanding of the mechanisms of membranous nephropathy and focal segmental glomerulosclerosis (FSGS). RECENT
FINDINGS: Recent studies of recurrent membranous nephropathy provide evidence of the presence of circulating recipient factor that targets the donor kidney and put forward the evidence of antiphospholipase A2 receptor antibody pathogenicity in some cases, point to a different pathogenesis of recurrent and de-novo membranous nephropathy, and stress the importance of early morphologic recognition of recurrent membranous nephropathy. New advances in understanding the FSGS include identification of soluble podocyte urokinase receptor as a circulating factor leading to the development and recurrence of FSGS after transplantation, imply that podocyte injury may be a reversible lesion, and suggest a dual role of activated parietal epithelial cells in sclerosing glomerular injury as well as in regeneration and repair.
SUMMARY: Several new mechanisms of glomerular injury have been implicated in the development of recurrent kidney diseases. When further confirmed, some of these might result in early diagnosis and development of better therapy of the respective disorders.