Polycystic Kidney Disease

This article is a part of University of Maryland Rounds, which features clinical and research updates from the University of Maryland School of Medicine and University of Maryland Medical Center. See more Rounds articles.

UMMC Mounts Aggressive Approach to Stubborn Kidney Disorder

With scant scientific advances in the treatment of polycystic kidney disease (PKD) — a condition that can enlarge kidneys to the size of footballs — a pace-setting team of physicians at University of Maryland Medical Center (UMMC) is researching the most promising therapies and offering leading-edge transplant surgery in an aggressive approach that distinguishes UMMC from most institutions in the nation.

Terry J. Watnick, M.D., an associate professor of medicine in the Division of Nephrology at University of Maryland School of Medicine, joined the faculty in 2012 from Johns Hopkins largely because of UMMC’s strong commitment to research in kidney diseases, of which PKD is the most common inherited form.

In her role at UMMC, Dr. Watnick continues to lead the Baltimore Polycystic Kidney Disease Research and Clinical Core Center one of four such centers in the United States — whose mission is to promote translational PKD research among an international group of investigators. Additionally, Dr. Watnick has been impressed by the depth and expertise of UMMC’s organ transplant team, one of a handful that removes dysfunctional kidneys and transplants a new one in a single operation.

“I would say we’re one of the few centers in the country that is bench-to-bedside in our approach to PKD,” she explains. “Some centers have a basic science operation and aren’t doing as much clinically, or vice versa. In our center, we encompass the whole gamut.” 

PKD Triggers Serious Complications

With gene mutations to blame for the vast majority of cases, PKD is estimated to affect as many as 1 in 500 people in the United States who often develop symptoms in their 30s or 40s and full-blown kidney failure in their 50s. Dr. Watnick sees several hundred PKD patients each year at UMMC. 

It’s a challenging disease to live with, gradually cramming the kidneys with fluid-filled sacs that displace normal kidney tissue and render kidneys ineffective in their primary role of clearing toxins and fluids from the body. Often, PKD triggers serious complications that include high blood pressure, polycystic liver disease and even brain aneurysms. 

“Some patients complain about significant abdominal distension,” Dr. Watnick says. “These kidneys get very large, the liver can also get large and people have a hard time doing simple things, like bending over to tie their shoes. Other symptoms include acute and chronic kidney pain, blood in the urine, infections and difficulty breathing.”

But thus far, no treatment has been developed to stop the progression of PKD — a problem Dr. Watnick’s current research hopes to improve. Current therapies attack only the symptoms and attempt to prolong native kidney function for as long as possible. 

UMMC is participating in another multi-center trial of Tolvaptan in patients with ADPKD. Tolvaptan is a drug that has previously shown some benefit in slowing both loss of kidney function and kidney cyst growth in ADPKD and is already approved for low sodium levels (hyponatremia) which can be associated with congestive heart failure and liver disease. This research complements Dr. Watnick’s work with the Baltimore Polycystic Kidney Disease Research and Clinical Core Center, which is supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). 

Renowned Transplant Team Offers Unusual Surgery

Most of the roughly 50% of PKD patients who develop end-stage kidney disease will need a kidney transplant, and UMMC’s ability to remove both diseased kidneys and transplant a new one in a single surgery is one of the program’s strengths. With 6 to 7 PKD patients receiving new kidneys at UMMC each year, the technically challenging operation is possible with a deep team of transplant surgeons that performs hundreds of organ transplants annually. A single operation can also hasten recovery and reduce anesthesia exposure. 

The faculty’s expertise can also pinpoint which patients are the best candidates for the procedure instead of undergoing other treatments, such as removing diseased kidneys and administering dialysis while awaiting a new organ.

"The excellent outcomes suggest that the combined operation should be preferred for patients with symptomatic APKD to avoid multiple operative procedures, prolonged dialysis, and increased costs related to staged operations," says Jonathan Bromberg, M.D., Ph.D., professor of surgery at the University of Maryland School of Medicine and chief of the division of transplantation at UMMC.

“There’s a critical mass of investigators here who are interested in various aspects of kidney disease, and the environment is very supportive of kidney research,” Dr. Watnick says. “Plus, we also have a strong transplant center, which is important for PKD patients since we don’t have another treatment yet. We have both strong basic science and clinical programs and we participate in clinical trials so that sets us apart.” 

Dr. Watnick can be reached at 410.706.5803.