Stem Cell Therapy Holds Promise for Kidney Disease

By Denise Mann HealthDay Reporter | HealthDay Thu, Aug 4, 2011

THURSDAY, Aug. 4 (HealthDay News) -- Researchers may be one step closer to harnessing the power of stem cells to help treat, and potentially cure, kidney disease.

Two new studies, both published in a recent issue of the Journal of the American Society of Nephrology, demonstrate that kidney cells can be reprogrammed to morph into other types of kidney cells needed to repair damage.

In one report, scientists out of Monash University in Australia extracted kidney cells and reprogrammed them so they could behave like other kidney cells. In a second related study, researchers from the Chinese Academy of Sciences in Guangzhou, China, collected kidney cells from urine and were also able to reprogram them.

The next step is to see if the cell lines -- called induced pluripotent stem cells (iPSC) -- can be expanded, and then injected back into people with kidney disease to develop functional tissue and/or organs. While this may be years off and there are many steps left to take, the technology has the potential to cure certain hereditary forms of kidney disease and acute kidney injury, and could eliminate the need for dialysis and/or kidney transplants in some patients with end-stage kidney disease.

Dr. Ivonne Schulman, an assistant professor of clinical medicine and nephrologist at the University of Miami's Interdisciplinary Stem Cell Institute in Florida, said that this is the first time that researchers have shown that kidney cells could be reprogrammed and made to behave like embryonic stem cells, meaning they have the potential to differentiate into other types of kidney cells.

"Two papers back-to-back show that two different kidney cell types are able to be reprogrammed," she said. "This is very significant."

The ultimate goal would be to inject these cells back into patients and try to regenerate kidney tissue, Schulman explained. "It could theoretically help all types of kidney disease," she said. "It just depends on the ability of these cells to differentiate back into the cell types needed for that disease."

In one of the studies, researchers were able to collect the kidney cells from urine, which means that they could be collected at anytime, eliminating the need for cell banks. "This makes it very simple," Schulman added.

Dr. Jeffrey I. Silberzweig, co-medical director of the Rogosin Institute Manhattan Dialysis Center in New York City, said that the benefits could be exponential. "The idea that you can have the ability to do stem cell transplants during the early stage of kidney disease and regenerate the damaged part of the kidney would be a tremendous benefit for patients and the country as a whole," he said.

The current treatment for end-stage kidney disease includes dialysis and/or kidney transplantation. Dialysis, which outsources kidney function, is uncomfortable, time-consuming and costly, he noted. Plus, "the supply of kidneys available for transplantation is way behind the number of people who need them," Silberzweig said. Intervening earlier with stem cell therapy could prevent things from ever getting that far.

"If it reaches a point where this technology becomes practical, patients would fall over each other getting in line to do it," Silberzweig said.

"This is a critical and important first step," said Dr. Samuel Saltzberg, a transplant nephrologist at Rush University Medical Center in Chicago. "We have quite a way to go to get to a point where we can impact kidney disease -- especially in diseases when the whole organ needs to be repaired."

In an editorial accompanying the new studies, Dr. Ian Rogers of Mount Sinai Hospital in Toronto wrote that kidney disease may just be the tip of the iceberg. "The advantage of these cells for the diagnosis and treatment of kidney disease is great -- but the ease of collection and the high frequency of reprogramming also means there may be benefits to urine cells for iPSC production beyond kidney disease."