What Is Polycystic Kidney Disease (PKD)? (video/podcast)

Polycystic kidney disease affects millions of people, but many don't even know that they have it. Commonly referred to as PKD, it causes fluid-filled cysts to form in both kidneys, eventually leading to progressive loss of kidney function and, potentially, kidney failure.

In this video, San Diego Health host Susan Taylor talks with Kimberly Harper, MD, a nephrologist at Scripps Clinic, about polycystic kidney disease symptoms, diagnosis and treatment.

A normal kidney has a very smooth contour and surface. In people with polycystic kidney disease, cysts develop in the kidneys and compress the normal kidney tissue as they grow and multiply. This can damage the kidneys, disrupt their normal function and lead to the release of hormones which raise blood pressure. High blood pressure, or hypertension, is a concern for people with PKD.

“It is also common for patients with PKD to have cysts in their liver. This is especially important for women because estrogen allows and promotes the growth of these liver cysts,” says Dr. Harper. “We generally recommend that women with polycystic kidney disease avoid taking extra estrogen, which can be found in birth control pills or hormone replacement therapies.”

PKD is the most common genetic kidney disease and the fourth leading cause of kidney failure, affecting about 1 in 500 people. However, many people who have PKD do not have any symptoms. If symptoms are present, they may include hypertension, blood in the urine or pain in the kidney area.

A small percentage of PKD patients may develop a cerebral aneurysm, which is a weakness in the blood vessel that feeds the brain. Without treatment, a cerebral aneurysm can rupture and become life-threatening. For this reason, patients with PKD should talk with their nephrologist about the need for a cerebral aneurysm screening test. Typically, this is a radiology image of the head to evaluate the blood vessels.

In most cases, your doctor will order blood and urine tests to assess your kidney function. If these tests indicate any concerns about your kidney function, the next step will be a kidney ultrasound to diagnose PKD.

PKD is a genetic disease, so if you have a family history of it, you should have routine blood pressure checks and blood and urine tests to detect any potential problems. Patients who have a parent with PKD have a 50% higher risk of developing it.

“Early detection of PKD is key because we have very effective treatments that can slow the progression of this disease and improve outcomes,” says Dr. Harper. “Additionally, if you have PKD and you would like to have children, we do have assisted reproductive technologies that can screen for the genetic mutation, which will decrease your chance of transmitting this disease to your child from 50% down to only 1 to 2%.”

While there is no cure for PKD, treatments can help slow the progression.

“Scripps Clinic Nephrology was involved with a landmark clinical trial that led to the development of the first FDA-approved treatment for polycystic kidney disease,” says Dr. Harper. “This medication can significantly slow the growth of the kidney cyst, which means our patients can have years more of life without kidney failure.”

She adds that it is important for PKD patients to keep their blood pressure under control, follow a kidney-friendly, mostly plant-based diet that is lower in sodium, and stay adequately hydrated. For most patients, that means drinking 2.5 liters or 85 ounces of water a day.

Other important lifestyle factors include exercising regularly, losing weight if needed, avoiding tobacco and controlling your blood sugars. Also be sure to review all your prescription and over-the-counter medications, supplements, vitamins and teas with your nephrologist.

Without treatment for aggressive PKD, patients typically lose kidney function faster and develop kidney failure at a younger age, leading to the need for kidney dialysis.

“If you do have progressive kidney dysfunction, it is important that you have a kidney transplant evaluation when you are eligible,” says Dr. Harper. “This can significantly decrease the amount of time you need to be on dialysis and, in some cases, can prevent the need for dialysis altogether.”