Lupus nephritis is inflammation of the kidney that is caused by systemic lupus erythematous (SLE). Also called lupus, SLE is an autoimmune disease. With lupus, the body's immune system targets its own body tissues. Lupus nephritis happens when lupus involves the kidneys.
Up to 60% of lupus patients will develop lupus nephritis. When the kidneys are inflamed, they can't function normally and can leak protein. If not controlled, lupus nephritis can lead to kidney failure.
Symptoms of Lupus Nephritis
Lupus nephritis is a serious problem. Its symptoms, though, are not always dramatic. For many, the first noticeable symptom is swelling of the legs, ankles and feet. Less often, there can be swelling in the face or hands.
Other symptoms can vary from person to person and from day to day. They may include:
- Weight gain
- High blood pressure
- Dark urine
- Foamy, frothy urine
- The need to urinate during the night
Not all urinary or kidney problems in people with lupus are due to lupus nephritis. People with lupus may also be prone to urinary tract infections. These cause burning on urination and require treatment with antibiotics. Certain lupus medications can also affect the kidneys and cause swelling and other symptoms similar to those of lupus nephritis. Problems related to these drugs usually go away when the drugs are no longer used.
Lupus Nephritis Diagnosis and Treatment
The diagnosis of lupus nephritis begins with a medical history, physical exam, and evaluation of symptoms. You doctor will likely order tests to make or confirm a diagnosis. Tests used in diagnosing kidney problems include urine tests, blood tests, imaging tests such as ultrasound, and kidney biopsy.
There are five different types of lupus nephritis. Treatment is based on the type of lupus nephritis, which is determined by the biopsy. Since symptoms and severity vary from person to person, treatments are individually tailored to meet a person's particular circumstances.
Medications used in treatment can include:
- Corticosteroids. These strong anti-inflammatory drugs can decrease inflammation. Doctors may prescribe these until the lupus nephritis improves. Because these drugs can cause a variety of potentially serious side effects, they must be monitored carefully. Doctors generally taper down the dosage once the symptoms start to improve.
- Immunosuppressive drugs. These drugs, which are related to the ones used to treat cancer or prevent the rejection of transplanted organs, work by suppressing immune system activity that damages the kidneys. They include cyclophosphamide (Cytoxan), azathioprine (Imuran) and mycophenolate (Cellcept).
- Medications to prevent blood clots or lower blood pressure if needed
Even with treatment, loss of kidney function sometimes progresses. If both kidneys fail, people with lupus nephritis may need dialysis. Dialysis involves filtering the blood through a machine to remove waste products from the body.
Ultimately, it may be necessary to have a kidney transplant. In those cases, people will need additional drugs to keep their immune system from rejecting the transplanted kidney.
Lifestyle Changes for Lupus Nephritis
Certain lifestyle habits can help protect the kidneys. People with lupus nephritis should do the following:
- Drink enough fluids to stay well hydrated.
- Eat a low-sodium diet, especially if hypertension is an issue.
- Avoid smoking and drinking alcohol.
- Exercise regularly.
- Maintain a healthy blood pressure.
- Limit cholesterol.
- Avoid medications that can affect the kidneys, such as nonsteroidal anti-inflammatory drugs (NSAIDs).
Your doctor may also recommend that you eat a diet low in potassium, phosphorus, and protein if there is already loss of kidney function.
Although lupus nephritis is a serious problem, most people who receive treatment do not go on to have kidney failure.