Cellular therapies for kidney failure.

Dialysis and transplantation of human kidneys represent effective therapies to replace kidney function, but each has limitations. Xenotransplantation of whole kidneys from non-primate donors is complicated by humoral and severe cellular rejection. The use of individual cells or groups of cells to regenerate or repair damaged tissue (cellular therapies) offers an alternative for renal replacement. Cellular strategies include: incorporation of new nephrons into the kidney; growing new kidneys in situ/renal organogenesis; use of embryonic or adult stem cells; and nuclear transplantation/therapeutic cloning. These approaches circumvent humoral rejection of xenogeneic tissue. Cellular rejection is ameliorated if embryonic cells are transplanted. It is likely that replacement of renal function via one or more cellular approach will constitute a part of future mainstream medical practice.