New hope in kidney donor organs shortage

SCIENTISTS have successfully grown miniature human kidneys in mice

The breakthrough suggests that one day it might be possible to grow new kidneys for humans and so end the severe shortage of donor organs.

An Israeli team headed by Professor Yair Reisner of the Weizmann Institute of Science took human and pig stem cells which were destined to become kidney cells.

They transplanted them into mice and found both the human and pig tissue grew into perfect kidneys, the size of mouse organs.

The human and pig kidneys were functional, producing urine, and the blood supply within the new organs was provided by host blood vessels, rather than donor blood vessels, which greatly lowers the risk of rejection.

The findings suggest that human or pig foetal tissue might take on the shape and function of a healthy kidney if transplanted into humans as well.

Pig tissue as opposed to pig organs is not expected to cause the kind of rejection seen in cross species transplants.

The researchers therefore hope that pig stem cells might provide a source for those in need of a kidney.

The study, published in the journal Nature Medicine, pinpointed the ideal time during embryonic development in which the stem cells have the best chance to form well-functioning kidneys with minimal risk for immune rejection.

Their findings suggest that seven-to-eight-week tissue in humans and four-week-old pig tissue offers the best window of opportunity for transplantation.

The team said the research was in a pre-clinical study stage, but that if all went well, a treatment could follow within a few years.

In September this year American researchers said they had managed to grow teeth in rats.