Ira Kurtz, MD, chief of Nephrology at UCLA Health, believes the kidney is the human body's most fascinating organ — even smarter, he says, than the brain.
For Dr. Kurtz and his colleagues, the holy grail long has been the development of a wearable and an implantable artificial kidney to replace the cumbersome dialysis process that has been the standard treatment for renal failure since the 1950s.
Now, after a five-year collaboration between the US Kidney Research Corporation, the University of Arkansas and UCLA Health, Dr. Kurtz and a team of researchers are on the verge of achieving that goal with the introduction of an artificial kidney that can be worn inside a backpack. If things proceed as hoped, within a few years a similar device could be implanted in the body as an artificial organ.
In July 2019, U.S. nephrologists celebrated when then-President Donald Trump announced in an executive order that his administration wanted to transform the care for 37 million Americans suffering from kidney disease, which kills more people annually than most cancers.
“It made a major splash in the renal community because it was the first time kidney care had really reached that kind of level in the government,” Dr. Kurtz said.
With the U.S. government spending an estimated $114 billion in Medicare payments each year to care for patients with kidney disease, it seemed like a prudent move.
“The total amount the federal government spends on kidney care is approximately 20% of Medicare’s trillion a year budget,” Dr. Kurtz said. “It’s billions with a B. So this is one reason the federal government wants changes to be made. For the first time, all the forces started coming together. The government, universities and industry recognized we have to do something. We can’t continue managing patients the same way we have for 50 years or more. Everything we do is the same as when I was trained in the ’70s. There’s nothing new. It’s the same hemodialysis, the same peritoneal dialysis.”
The lack of progress over the years in treating people with kidney failure can be attributed, in part, to the characteristics that Dr. Kurtz finds most interesting about the organ. The kidneys act as a complex chemistry and biology lab – recognizing numerous substances (water, ions and organic molecules) that need to be excreted in the urine, thereby keeping the blood chemistry relatively constant. That makes the human heart seem like a much simpler organ, “just a pump,” he said.
And the brain? “It’s almost as smart as the kidney but a bit lazier, since it’s worked out all these ways to give itself the concept of holidays, weekends, etc., whereas the kidneys have to work 24/7,” Dr. Kurtz said.
“I was fascinated in medical school with the kidney’s function,” he said. “I couldn’t believe that nature could design such a brilliant device.”
It’s no wonder it’s taken technology awhile to catch up.
“The device we’re working on is complicated,” Dr. Kurtz said. “We have four separate components in it. The first component is called the ultrafiltration module, and it filters the blood. By filtering the blood, what I mean is that it prevents the cells in the blood and proteins from getting into the rest of the device.”
There are additional components in the device, including a nanofiltration module to prevent the excretion of sugar in the artificial urine and two custom-designed electrodeionization modules that transport various ions into the synthetic urine. One of the electrodeionization modules is specific for potassium.
“If your blood potassium changes by just a little bit, the electricity in your heart can just go wacko and your heart can stop,” Dr. Kurtz said. “So it’s very important that we keep the potassium in the blood within a certain range.”
Finally, the device includes a reverse osmosis module that ensures the appropriate amount of water is excreted in the synthetic urine.
The meticulous research is well worth the effort. More than 500,000 people in the U.S. are on dialysis because there aren’t enough human kidneys to go around for transplants. Every year, about 100,000 people die from the disease in the United States while another 100,000 are diagnosed with end-stage kidney failure, Dr. Kurtz said.
“That’s 2½ times the death rate for breast cancer, which is approximately 40,000 deaths per year, but the general public is not aware of it. Breast cancer advocates are so much more vocal; for example, there are many more marches and much more funding for research,” he said. “Furthermore, everyone is afraid of breast cancer and knows about it, whereas few people are aware that kidney deaths are 2½ times higher. Additionally, for example, prostate cancer deaths are approximately 30,000 per year. Kidney disease yearly deaths are approximately 3½ times that.”
In addition to refining an artificial kidney, researchers are working on xenotransplants – developing organs in cows or pigs with human HLA (human leukocyte antigens) that can be transplanted into humans. “Right now, if you put a cow or a pig kidney in a human, it will be rejected in a couple of hours; your body will just destroy it,” Dr. Kurtz said.
As a major recognition of their research, the team was a winner of the prestigious Kidney X innovation prize, sponsored by the U.S. Department of Health and Human Services and the American Society of Nephrology.
Dr. Kurtz estimates that his team needs another 18 months to refine the technology on the wearable artificial kidney and then will focus on the implantable artificial kidney.
“We’ve been able to get the funding every year for five years, but we need about another $8 million to take us to the finish line,” he said. “You know, it sounds like a lot, but it’s nothing compared to the $114 billion the U.S. government is spending on managing these patients. That’s the kind of funding we’re trying to somehow get. We’ve been talking to a number of different companies and entities. So far, not yet, but hopefully.”
Tina Daunt is the author of this article.