Lupus nephritis is an inflammatory disease of the kidneys that can occur as a result of systemic lupus erythematosus. The condition is chronic and can affect the brain, joints, kidneys, and skin. It arises because the immune system has been weakened by the primary disease of lupus erythematosus. Autoantibodies build up in capillaries contained in the kidneys, leading to the inflammation. This buildup can cause impairment of kidney function and possibly lead to renal failure.
What are the symptoms?
Symptoms of lupus nephritis may include swelling in the hands, feet, and around the eyes. There could be blood and proteins in the urine, and the urine may appear darker in color and foamy. The patient may develop high blood pressure. They often experience weight gain due to fluid rentention, although the appetite usually is poor and food intake decreases. Other possible symptoms are nausea, generalized itching, and fatigue. Depending on how much the lupus nephritis has progressed, there can be bone pain, confusion and fatigue as well as headaches.
How is it diagnosed?
Lupus nephritis can be diagnosed through imaging, urinalysis and biopsy. If high amounts of protein or red blood cells are found in the urine of a lupus erythematosus patient, they can be properly diagnosed with lupus nephritis, provided other causes have been ruled out. Other possible causes can be ruled out through inspection of the bladder with cystoscopy and/or imaging procedures. A biopsy may be done to closely examine kidney tissue in order to determine proper treatment.
Five classes of lupus nephritis can be diagnosed, from mild to severe, so treatment can be approached in several different ways.
How is it treated?
The treatment for lupus nephritis is dependent on severity of the disorder in the individual. High blood pressure should be managed with a combination of nutrition and medication. Most patients will be closely monitored for intake of sodium, potassium and protein. If the case is severe, they may need to restrict sodium to two grams a day with a decrease in fluid intake to reduce swelling. Less severe cases may be treated with corticosteroids, with the most severe lupus nephritis usually requiring immunosuppressants or chemotherapy. Risks of these treatments are carefully weighed against benefits, as severe negative side effects related to increased risk of infections are a possibility.
In lupus nephritis, sometimes protein leakage from the kidneys must be addressed with the use of angiotension-converting enzyme inhibitors. The inhibitors also help to lower the patient’s blood pressure. Also available are angiogenesis II receptor blocker drugs, which can slow the disease as well as reducing protein leakage.
In case of renal failure, dialysis or kidney transplant may be necessary.
The outlook for patients with lupus nephritis is dependent on the class and severity of the case and how damaged the kidneys have become. At this time, although research continues, there is no known preventive measure for a lupus patient to take against the disease.
National Institute of Health
Signet/Mosby Medical Encyclopedia