Stem cell hope for kidney patients

The US study identified stem cells in adult zebra fish kidneys that can be transplanted from one fish to another. Photo / Thinkstock

American experiments led by a New Zealander have proved that treating kidney disease with a form of stem cell therapy is theoretically possible - a potentially revolutionary finding for those facing a kidney transplant or life-long dialysis.

The research was conducted on zebra fish but holds hope of application to humans. "[It] provides a proof of principle that adult kidney stem cells exist in nature and that treating renal disease with a stem cell-type therapy is theoretically possible," Associate Professor Alan Davidson, of Auckland University, says in a Harvard University publication. He led the research - published in the journal Nature - as an assistant professor at Harvard Medical School in the US, before returning to New Zealand in December.

The US study identified, for the first time, stem cells in adult zebra fish kidneys that can be transplanted from one fish to another and generate new nephrons, the basic blood filtration structure of the kidneys.

Professor Davidson was given a Rutherford Distinguished Fellowship by the Royal Society of NZ so he could return here, and won a three-year Marsden grant of more than $900,000 to continue his work on kidney regeneration using stem cells.

In New Zealand, more than 3500 people have end-stage kidney disease - nearly half of them as a result of damage caused by diabetes. The number is expected to double by 2016 because of obesity and diabetes.

In addition it is estimated that around 300,000 people have significant kidney impairment.

Professor Davidson said yesterday that it was not certain whether the stem cells in the US research were unique to zebra fish.

It is thought that while kidney stem cells exist in humans and other mammals during the fetal stage, they disappear around the time of birth.

"Humans are stuck with their number of nephrons at birth, for life," he said. "This is a big deal because if you have growth retardation or other issues during pregnancy, you can be born with a very reduced endowment of nephrons, so predisposing to renal disease later on."