Renal Papillary Necrosis

What is renal papillary necrosis?

Kidneys filter waste out of your blood and help maintain fluid levels in your body. Most people are born with two kidneys.

Blood enters your kidneys through your renal arteries, which split into smaller and smaller blood vessels. In the outer part of your kidney, special cells sit next to the tiny blood vessels and pull waste products and water out of your blood.

The watery waste, or urine, travels through tiny tubes toward the center of your kidney. This middle region of your kidney is the medulla. It contains funnel-shaped sections of tissue. Within each funnel, the tiny tubes empty into larger collecting ducts. The area at the tip of the funnel where the collecting ducts meet is your renal papilla.

From the renal papillae, urine empties into the center area of your kidney. It then travels through your ureter to your bladder and out of your body through your urethra.

Renal papillary necrosis is the death of cells and tissue in your medulla and renal papillae. These areas of dead tissue reduce kidney function and can lead to kidney failure.

Who is at risk for renal papillary necrosis?

It occurs most often in people over 60 and is more common in women and people assigned female at birth.

What causes renal papillary necrosis?

Many conditions and factors can cause renal papillary necrosis. The most common are:

• Diabetes.
• Overuse of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen and naproxen.
• Sickle cell disease.

Other conditions and diseases that can lead to renal papillary necrosis include:

• Chronic liver disease.
• Pyelonephritis, a bacterial infection of your kidney.
• Renal tuberculosis, a form of tuberculosis found outside of your lungs.
• Renal vein thrombosis, a blood clot in the vein that carries blood away from your kidneys.
• Ureteral obstruction, blockage of your ureter.
• Vasculitis, inflammation of blood vessels.

Are both kidneys affected by renal papillary necrosis?

In about 7 out of 10 cases, the condition affects both kidneys.

What are the symptoms of renal papillary necrosis?

People in early stages may not have noticeable symptoms. This makes early diagnosis and treatment difficult. But healthcare providers may catch renal papillary necrosis early during evaluation and treatment for the conditions that cause it.

As renal papillary necrosis progresses, symptoms may include:

• Dysuria, painful urination.
• Fever and chills.
• Hematuria, blood in your urine visible with the eye or under microscopic examination.
• Nocturia, frequent urination at night.
• Pyuria, unusually high amount of white blood cells in urine.
• Severe flank pain on either side of your back.
• Urinary tract infections.

How is renal papillary necrosis diagnosed?

Healthcare providers diagnose renal papillary necrosis using:

• Urography involves an X-ray, CT scan or MRI of your kidneys. Before the test, you receive an intravenous (IV) dye, called contrast, which helps your provider see damaged areas of your kidneys.
• Ureteroscopy allows your provider to look directly inside of your kidneys using a thin, flexible tube with a camera at the end.
• Kidney biopsy involves examining a small tissue sample under a microscope.

What type of blood and urine tests help diagnose renal papillary necrosis?

Kidney function tests can also help your provider diagnose this condition. These include:

• Blood urea nitrogen (BUN): BUN tests measure the amount of nitrogen in your blood. Higher levels of nitrogen indicate your kidneys aren’t filtering properly.
• Creatinine: Creatinine is a product of the normal wear and tear of the muscles in your body. Normally, your kidneys clear it from your body. Higher levels of nitrogen indicate your kidneys aren’t filtering properly.
• Estimated glomerular filtration rate (eGFR): This is a calculation based on protein levels in your blood, creatinine, age, sex, size and race. eGFR is an estimate of how well your kidneys are filtering blood.
• Urinalysis: A urinalysis includes a visual exam, microscopic exam and chemical tests of your urine. These tests can detect blood, including red blood cells and white blood cells. Under a microscope, your provider may also see broken-off pieces of your renal papillae.
• Urine protein/creatinine ratio: This test looks for protein in your blood, which is a sign of kidney damage.

What are the complications of renal papillary necrosis?

If not treated, renal papillary necrosis can lead to chronic kidney disease (CKD), kidney failure, dialysis and kidney transplant. Renal papillary necrosis is also associated with transitional cell cancer of the kidney or ureter.

How is renal papillary necrosis treated?

There isn’t a specific treatment for renal papillary necrosis. Treatment involves managing the underlying cause to limit further damage to your kidneys.

The effectiveness of treatment will depend on the extent of the damage. In severe cases, renal papillary necrosis may continue to progress after treatment. In less severe cases, kidney function may stabilize or even improve.

How can I prevent renal papillary necrosis?

You can prevent this condition by maintaining good overall health. Use NSAIDs (or other over-the-counter medications) according to the manufacturer’s or provider’s instructions.

If you have diabetes, sickle cell disease or another condition that causes renal papillary necrosis, follow your healthcare provider’s care instructions and attend regular appointments. You’ll need routine lab tests to assess your kidney function and detect any changes early.

What is the prognosis for people with renal papillary necrosis?

Your prognosis depends on the cause and extent of the damage. People with diabetes have poorer outcomes because it’s a long-term disease and not always well-controlled. If you have diabetes, managing it the best you can will help you prevent damage to your kidneys.

Severe renal papillary necrosis can be severe and lead to dialysis and kidney transplantation. It can be fatal if infections develop. Death can also occur due to kidney failure.

In sickle cell disease, renal papillary necrosis is one of several complications that can develop in your kidneys. Together, these complications greatly reduce a person’s life expectancy.

When should I contact my healthcare provider?

Talk to your provider if you experience:

• Blood in your urine.
• Fever or chills.
• Painful urination.
• Pain on either side of your back between your hip bones and ribs.

A note from Cleveland Clinic

Your kidneys play an essential role in your body, filtering out waste and maintaining water balance. Uncontrolled diabetes, overuse of NSAID pain relievers and other conditions can damage your kidneys and cause renal papillary necrosis. In the early stages of renal papillary necrosis, you may not even know you have a problem. If you have diabetes or frequently take NSAIDs, talk to your provider about steps you can take to protect your kidneys.