Lupus and Kidney Damage

Category: Systemic Lupus Erythematous Published on Wednesday, 25 June 2008 Written by Yong Tsai, MD

Lupus, an autoimmune disease that can affect the joints, skin and other organs, was named the Latin word for wolf because of its telltale facial rash that marks the cheeks and bridge of the nose with a wolf-like mask.

Sonya, a 31-year-old secretary, had not seen a doctor for her lupus for several years because she had no symptoms other than the typical wolf-like rash. However, a recent physical showed some red blood cells in her urine and elevated BUN and Creatinine blood tests. Even though, Sonya had no symptoms, her lupus had affected her kidneys.


Lupus occurs when the body fails to recognize its own components and attacks them with auto (self) anti (against) bodies. Patients with lupus have several autoantibodies, which can create an immune chain reaction. When autoantibodies bind with our own tissue, they circulate in our blood stream, creating a deposit in our kidneys, causing inflammation that can result in kidney damage.


Our kidneys, like a water treatment plant, filter our body’s waste products and excrete them through our urine. Each kidney has approximately 1.2 million nephrons (functional units), divided into two parts: the glomerulus (filter) and the tubule (collection tube). Our kidneys maintain the volume and composition of body fluids, excreting waste products, eliminating toxins, and regulating blood volume. 


Glomerulonephritis, often associated with lupus, occurs when inflammation damages the kidney’s filtering system (glomerulus) and red blood cells and protein (albumin) from the blood leaks into the urine. The process affects the body’s balance of fluids and salts, and can cause edema (swelling) especially in the abdomen, ankles and feet. When nephritis is untreated, the kidney’s ability to cleanse the body of waste products can be impaired. In severe cases, if these poisons accumulate, uremia (weakness, nausea, vomiting, itching, and changes in brain function) may occur.


Since patients with nephritis usually have few symptoms, regular blood test monitoring is important. Elevated blood nitrogen (BUN) or creatinine (Cr) usually reflects abnormal kidney function. However, urinalysis is most accurate in detecting nephritis because of the presence of blood (hematuria) or protein (uremia) in the urine.


Potent immuno-suppressant drugs such as high dose corticosteroids, Imuran, and Cytoxan are effective with kidney involvement. Frequently, kidney biopsy is indicated to confirm the diagnosis of nephritis or to determine the degree of inflammation and scarring and as a guide for treatment.

Even though kidney involvement is quite common in SLE, most cases are mild, and even need no treatment. In the past, kidney failure was a major cause of death in lupus. Fortunately, early detection followed by aggressive treatment have made kidney damage a less common complication of lupus today.

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