Polycystic Kidney Disease (PKD)

What Is Polycystic Kidney Disease?

Polycystic kidney disease (PKD) is an inherited kidney disorder. It causes fluid-filled cysts to form in the kidneys. PKD may impair kidney function and cause kidney failure.

According to the University of Chicago Medicine (UCM), PKD is the fourth leading cause of kidney failure. About half of patients with PKD also develop cysts of the liver (UCM, 2012).

What Causes Polycystic Kidney Disease?

PKD is generally inherited. Less commonly, it develops in patients who have other serious kidney problems.

There are three types of PKD.

Autosomal Dominant PKD (ADPKD)

According to UCM, ADPKD accounts for about 90 percent of PKD cases. If one parent has the disorder, the chance of passing it down to their child is 50 percent (UCM, 2012). ADPKD is sometimes called adult PKD. Symptoms usually develop later in life, between the ages of 30 and 40. However, symptoms can start in childhood.

Autosomal Recessive PKD (ARPKD)

ARPKD is much less common than ADPKD. It is also inherited. However, both parents must carry the gene for the disease. People with ARPKD will not have symptoms unless they have two copies of a disease gene.

There are four types of ARPKD:

  • perinatal form (the disorder is present at birth)
  • neonatal form (the disorder occurs within the first month of life)
  • infantile form (the disorder occurs when the child is 3 to 6 months old)
  • juvenile form (the disorder occurs after the child is 1 year old)

Acquired Cystic Kidney Disease (ACKD)

ACKD is not inherited. It usually develops in patients who already have other kidney problems. It is more common in those who have kidney failure or are on dialysis.

ACKD usually occurs later in life.

What Are the Symptoms of Polycystic Kidney Disease?

The main symptoms of PKD include:

  • pain or tenderness in the abdomen
  • blood in the urine
  • frequent urination
  • pain in the sides
  • urinary tract infection (UTI)
  • kidney stones

Other symptoms include:

  • pain or heaviness in the back
  • skin that bruises easily
  • pale skin color
  • fatigue
  • joint pain
  • nail abnormalities

Some disorders that are associated with PKD include:

  • aortic or brain aneurysms (weakened areas in the walls of arteries)
  • cysts in the liver, pancreas, and testicles
  • diverticula (pouches or pockets in the wall of the colon)
  • cataracts or blindness
  • liver disease
  • mitral valve prolapse

Children with autosomal recessive PKD may have symptoms such as:

  • high blood pressure
  • urinary tract infection (UTI)
  • frequent urination

Symptoms in children may resemble other disorders. It is important to get medical attention for a child experiencing the symptoms listed above.

How Is Polycystic Kidney Disease Diagnosed?

PKD is an inherited disorder. Therefore, your healthcare provider will probably review your family history. They may initially order:

  • a complete blood count (CBC) looking for anemia or signs of infection
  • a urinalysis looking for blood and/or protein

Your health care provider may use imaging tests to look for cysts of the kidney, liver, and other organs. Imaging tests used to diagnose PKD include:

  • abdominal ultrasound: the most useful, non-invasive study using sound waves to look for cysts
  • abdominal CT scan: can detect smaller cysts in the kidney; uses X-rays to build a cross-section of your abdomen
  • abdominal MRI scan: uses strong magnets to image your body to visualize kidney structure and look for cysts
  • abdominal ultrasound: uses sound waves to see inside your body
  • intravenous pyelogram (IVP): uses a dye to make your blood vessels show up more clearly on an X-ray

A cerebral angiography may be ordered for patients with PKD who have a higher incidence of cerebral aneurysms

What Is the Treatment for Polycystic Kidney Disease?

The goal of PKD treatment is to manage symptoms. Controlling high blood pressure is the most important part of treatment. Treatment may include:

  • pain medication
  • blood pressure medication
  • antibiotics (to treat UTI)
  • a low-sodium (salt) diet
  • diuretics (to help remove excess fluid)
  • surgery (to drain cysts and help relieve discomfort)

With advanced PKD, dialysis and kidney transplant may be necessary. One or both of the kidneys may need to be removed.

What Are the Complications of Polycystic Kidney Disease?

PKD is associated with many complications. These include:

  • anemia (insufficient red blood cells)
  • bleeding or bursting of cysts
  • high blood pressure
  • cysts on the liver and/or liver failure
  • kidney stones
  • recurrent urinary tract infections (UTIs)
  • cardiovascular disease
  • brain aneurysms

What Is the Outlook for Patients with Polycystic Kidney Disease?

In most people, PKD slowly gets worse over time. It may lead to liver disease. Eventually, the disease ends in kidney failure.

Proper medical care can relieve PKD symptoms for years. If you dont have other medical problems, you may be a good candidate for a kidney transplant.

Talk to a genetic counselor if you have a family history of PKD and are planning to have children.