Learning About Lupus Nephritis

Lupus nephritis is a type of kidney disease caused by lupus.

Lupus is an autoimmune disease. This means the immune system, which works to protect your body from illness, attacks healthy tissue instead. In lupus nephritis, the tiny filters inside your kidneys get damaged.

Lupus is more common in women and in people who are Black, Hispanic, and Asian. About half of adults with lupus will get lupus nephritis. Men and women have the same risk of developing it. Talk to your doctor if you have questions about your risk.

In lupus, the immune system makes certain antibodies that attack healthy tissue. These antibodies can build up in the kidneys and cause inflammation (swelling). This harms the tiny filters in your kidneys. It keeps them from working like they should.

It's not clear why some people with lupus develop kidney problems and others do not.

Many people have no symptoms in the early stages. As kidney damage gets worse, you may notice:

• Foamy or bubbly urine.
• Urine that looks pink, red, or brown due to blood.
• Swelling in your legs, feet, or ankles or around your eyes.
• High blood pressure.
• Needing to urinate more often, especially at night.
• Feeling very tired.

Your doctor may use several tests to check for lupus nephritis. Blood tests measure a substance called creatinine and a number called the estimated glomerular filtration rate (eGFR). This checks how well your kidneys are filtering. Urine tests look for protein and blood. Imaging tests, such as an ultrasound, can check the size and shape of your kidneys.

Your doctor may also recommend a kidney biopsy. For a biopsy, a doctor removes a very small piece of kidney tissue. The tissue is then checked under a microscope. This can confirm lupus nephritis and show how much damage has happened.

Lupus nephritis is grouped into six classes. The classes are based on how severe the kidney damage is. Knowing the class helps your doctor choose the right treatment.

Treatment depends on how much kidney damage there is. The main goals are to reduce inflammation, protect the kidneys, and prevent flares. Flares are periods when symptoms get worse.

The main treatment uses medicines that calm the immune system. These are called immunosuppressants. They're often used along with corticosteroids (steroids), which help bring down inflammation quickly. Blood pressure medicines may also be used to help protect the kidneys from further damage. Some newer, targeted medicines are approved for certain types of lupus nephritis as well.

If the kidneys stop working, dialysis or a kidney transplant may be needed. Seeing both a kidney doctor (nephrologist) and a lupus doctor (rheumatologist) regularly can be an important part of long-term care.