Xenotransplantation of renal primordia

The limited availability of donor organs restricts the number of kidney transplantations performed per year. One novel solution to this shortage envisions 'growing' new kidneys in situ via xenotransplantation of renal primordia. To be successful, such an approach would require the following criteria to be met: that transplants are 'grown' in a location that renders their subsequent excretory function possible; that developed transplants have normal morphology and function; that transplanted metanephroi become well integrated into the host, in terms of inducing a state of immune tolerance and being vascularized by host vessels; and that source material for metanephros transplants is easy to access. This review summarizes recent work addressing these issues.