Lupus nephritis is a kidney disorder that is a complication of systemic lupus erythematosus.A.D.A.M.

Causes, incidence, and risk factors

Systemic lupus erythematosus (SLE, or lupus) is an autoimmune disease. This means there is a problem with the body's immune system.

Normally, the immune system helps protect the body from infection or harmful substances. But in patients with an autoimmune disease, the immune system cannot tell the difference between harmful substances and healthy ones. As a result, the immune system attacks otherwise healthy cells and tissue.

SLE may damage different parts of the kidney, leading to interstitial nephritis, nephrotic syndrome, and membranous GN. It may rapidly worsen to kidney failure.

Lupus nephritis affects approximately 3 out of every 10,000 people. In children with SLE, about half will have some form or degree of kidney involvement.

More than half of patients have not had other symptoms of SLE when they are diagnosed with lupus nephritis.

SLE is most common in women ages 20 - 40. For more information, see: systemic lupus erythematosus.

Symptoms

Symptoms of lupus nephritis include:

• Blood in the urine
• Foamy appearance to urine
• High blood pressure
• Swelling of any area of the body

For general lupus symptoms, see the article on SLE.

Signs and tests

A physical exam shows signs of decreased kidney functioning with body swelling (edema). Blood pressure may be high. Abnormal sounds may be heard when the doctor listens to your heart and lungs.

Tests that may be done include:

• ANA titer
• BUN and creatinine
• Complement levels
• Urinalysis
• Urine protein

This list may not be all-inclusive.

A kidney biopsy is not used to diagnose lupus nephritis, but to determine what treatment is appropriate.

Treatment

The goal of treatment is to improve kidney function and to delay kidney failure.

Medicines may include corticosteroids or other medications that suppress the immune system, such as cyclophosphamide, mycophenolate mofetil, or azathioprine.

You may need dialysis to control symptoms of kidney failure, sometimes for only a while. A kidney transplant may be recommended. People with active lupus should not have a transplant because the condition can occur in the transplanted kidney.

Expectations (prognosis)

How well you do depends on the specific form of lupus nephritis. You may have flare-ups, and then times when you do not have any symptoms.

Some people with this condition develop chronic kidney failure.

Although lupus nephritis may return in a transplanted kidney, it rarely leads to end-stage kidney disease.

Complications

• Acute renal failure
• Chronic renal failure
• End-stage renal disease
• Nephrotic syndrome

Calling your health care provider

Call your health care provider if you have blood in the urine or swelling of your body.

If you have lupus nephritis, call your health care provider if you notice decreased urine output.

Prevention

There is no known prevention for lupus nephritis.

References

1. Appel GB. Glomerular disorders and nephrotic syndromes. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 122.
2. Appel GB, Radhakrishnan J, D’Agti V. Secondary glomerular disease. In: Brenner BM, ed. Brenner and Rector's the Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 31.

Review Date: 9/19/2011.

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Herbert Y. Lin, MD, PHD, Nephrologist, Massachusetts General Hospital; Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.