Children's Hospital Colorado

Kidney Disease Research

Kidney | August 22, 2016
Dr. Melissa Cadnapaphornchai standing in the Kidney Center at Children's Hospital Colorado.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) begins before birth, with a glitch in the coding of the gene that helps build renal tubules causing small dilations to occur while these small tubes are developing. The dilations fill with fluid and seal themselves off into cysts. The process repeats until the then adult kidney — normally the shape of a bean and the size of a fist — becomes so calcified and filled with cysts it looks like a geode, bloats to the size of a football, and eventually shuts down.

About 50 percent of babies born with ADPKD will develop kidney failure by age 60. Affecting about one in 500 to 1,000 people, it’s a leading cause of kidney transplants in the U.S. What’s more, this disease does plenty of damage along the way. Cysts injure kidney tissue as they expand, triggering it to release hormones that raise the blood pressure, stiffen the arteries and cause the body to retain water and salt.

New discoveries about Autosomal Dominant Polycystic Kidney Disease (ADPKD)

“We are the only group doing large-scale drug trials for this disease in children,” says Children’s Hospital Colorado Pediatric Nephrologist Dr.  Melissa Cadnapaphornchai “For many years all we could offer kids with ADPKD was medications to treat the symptoms. It was like, well, we’ll do our best.”

That recently changed with the discovery, first observed at neighboring University of Colorado Hospital, of an interesting side effect of an adult cholesterol drug. The drug, Pravastatin, works by blocking cholesterol-producing enzymes, enzymes that also seem to aid the growth of cysts.

At least in theory: the physiology isn’t completely understood. But the fact, shown in trials led by Dr. Cadnapaphornchai at Children’s Colorado, is that using Pravastatin to treat ADPKD slows cyst growth considerably. Slowed cyst growth ostensibly means less tissue damage and hormone problems, and longer kidney life. It’s the first drug to treat the root problem of ADPKD.

What this means for combating cysts in children and adults

This discovery is great for kids, but it’s also great for public health. A drug — or some eventual combination of drugs — that slows down or even stops cyst growth can certainly help a 40-year-old, but how much more good could it do if that patient had started at 8 years old, or even 2?

A drug treatment’s best effects may be revealed over the course of many years. “We’re looking at younger and younger kids,” says Dr. Cadnapaphornchai. “The Pravastatin study gave us a great database of kids to follow long-term.”

Learn more about the pediatric urology clinical research at Children’s Hospital Colorado.