Sonya, a 31-year-old secretary, had not seen a doctor for her lupus for several years because she only had mild joint pain and the facial rash.   However, a recent physical showed some red blood cells in her urine and elevated BUN and Creatinine in her blood tests.  Even though Sonya had few symptoms, her lupus had already affected her kidneys.

Systemic lupus erythematous (SLE), a systemic autoimmune disease, can affect the joints, skin, kidneys and other organs.   Lupus is named the Latin word for wolf because of its telltale malar rash.  Lupus occurs when our immune system fails to recognize its own tissues (antigens) and attacks them with auto- (self) antibodies.  Patients with lupus have several auto-antibodies such as anti-nuclear antibody (ANA), anti-double strand DNA (anti-ds DNA) and anti-phospholipid antibodies.  Anti-ds DNA antibodies play a significant role in kidney damage.  Anti-ds DNA can bind with kidney tissues (immune complex) and circulate in our blood stream.  When immune complex deposits in the kidneys, it causes inflammation that results 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, excrete waste products, eliminate toxins, and regulate blood volume.  When inflammation damages the kidney’s filtering system (glomerulus), it can cause 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 ankles and feet.  When inflammation 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 most patients with glomerulonephritis (inflammation of glomerulus) have few symptoms, regular blood and urine tests monitoring is important.  Elevated blood nitrogen (BUN) or creatinine (Cr) usually reflects abnormal kidney function. However, urinalysis can detect early kidney involvement because of the presence of blood cell or protein in the urine.  Potent immunosuppressant drugs, such as high dose corticosteroids, Imuran, Cellcept, and Cytoxan are effective with glomerulonephritis.  Frequently, a kidney biopsy is used to confirm the diagnosis or to determine the degree of inflammation and as a guide for treatment.