What is Uric Acid Nephropathy

Uric acid nephropathy develops due to buildup of uric acid

Uric acid is a chemical compound that is made when your body digests some kinds of food and also when your body breaks down dead cells. It is a waste product that is normally removed from your body by your kidneys. If you have too much uric acid in your blood, it can build up in your kidneys and cause damage (nephropathy).

There are two types of uric acid nephropathy:

• Sudden (acute) uric acid nephropathy results from a sudden buildup of uric acid.
• Long-term (chronic) uric acid nephropathy results from a slow buildup of uric acid over a long period of time.

What are the causes?

The exact cause of this condition may depend on the type of uric acid nephropathy:

• Acute uric acid nephropathy may be caused by:
  • Receiving medicines for the treatment of cancer (chemotherapy). Use of these medicines causes rapid breakdown of cells. The cell breakdown produces excess uric acid. As uric acid builds up in your kidneys, it causes an increase of pressure and a loss of blood supply. This makes your kidneys less able to filter blood and make urine.
  • A tumor (cancer) in the body.
  • Seizures.
  • Taking medicines that can cause excess uric acid. Examples are aspirin, water pills (diuretics), and medicines that are prescribed after an organ transplant.
  • Severe diarrhea, which causes fluid loss (dehydration).
• Chronic uric acid nephropathy may happen if you have high levels of uric acid in your body on a regular basis. One reason you may have high levels of uric acid is gout. With gout, excess uric acid forms into crystals. These crystals can get stuck inside joints and cause painful swelling. They may also build up in your kidneys and cause long-term damage.

What increases the risk?

You may be more likely to develop this condition if you:

• Are male.
• Are 50 years old or older.
• Have gout.
• Eat a lot of foods that are high in certain natural chemical compounds (purines). Shellfish and red meat contain a lot of purines.
• Drink alcohol.
• Have recently had heart surgery.

What are the signs or symptoms?

Signs and symptoms depend on the type of nephropathy that you have. They may include:

• Decreased urine output.
• Nausea and vomiting.
• Lack of energy.
• Seizures.
• Blood-tinged urine.
• Pain when passing urine.
• Pain in the sides of the lower back (flank pain).

In some cases, there are no symptoms.

How is this diagnosed?

Your health care provider may suspect uric acid nephropathy from your signs and symptoms, especially if you have gout. He or she may:

• Do a physical exam.
• Order tests to confirm the diagnosis. Tests may include:
  • Blood and urine tests. This is the best way to measure high levels of uric acid.
  • Imaging studies to check for kidney stones or kidney damage. These may include:
    • X-rays.
    • Ultrasound.
    • CT scan.
    • MRI.

How is this treated?

The goal of treatment is to lower the level of uric acid in your body and prevent kidney damage. This can be done by:

• Taking medicines that block the production of uric acid. The most commonly used medicine is allopurinol. If you are starting chemotherapy, ask your health care provider if you should start taking a medicine to prevent high uric acid.
• Starting a diet plan that lowers your intake of purines. Work with a diet and nutrition specialist (dietitian) to limit your intake of foods and drinks that increase uric acid.
• Preventing uric acid buildup. Drink plenty of water to maintain a good flow of urine and to lower the acidity of your urine. You may also need to take a medicine called bicarbonate.
• Resting the kidneys. This can be done by using a machine to clean your blood (hemodialysis), if necessary. In hemodialysis, your blood is removed, passed through a filtering machine, and then returned to your body. Several sessions of hemodialysis usually improve kidney function by removing uric acid.

Follow these instructions at home:

Eating and drinking

• Drink enough fluid to keep your urine pale yellow.
• Do not drink alcohol.
• Do not drink beverages that contain a type of sugar called fructose.
• Limit how much red meat and shellfish you eat.
• Include plenty of low-fat dairy foods in your diet.

General instructions

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Maintain a healthy weight. Lose weight as directed by your health care provider.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if you:

• Feel tired and have low energy, even when you get enough sleep.
• Have pain when passing urine.
• Have nausea or vomiting.

Get help right away if you:

• Produce very little urine, even when you drink enough fluids.
• Have blood in your urine.
• Have a seizure.

Summary

• Uric acid is a waste product that is normally removed from your body by your kidneys. If you have too much uric acid in your blood, it can build up in your kidneys and cause damage (nephropathy).
• Sudden (acute) uric acid nephropathy results from a sudden buildup of uric acid. Long-term (chronic) uric acid nephropathy results from a slow buildup of uric acid over a long period of time. This may happen if you have gout.
• The goal of treatment is to lower the level of uric acid in your body and prevent kidney damage.