Lupus nephritis is an inflammation of the kidney caused by systemic lupus erythematosus (SLE), a disease of the immune system. It is characterized by damage to the glomerulus and progressive loss of kidney function. Lupus nephritis is triggered when antibodies and complement build up in the kidneys and cause inflammation, damaging the glomeruli. It also causes nephrotic syndrome with excessive protein excretion and may progress rapidly to renal failure. Thus, nitrogen waste products build up in the bloodstream.
The signs and symptoms of Lupus nephritis are weight gain, high blood pressure, darker foamy urine or swelling around the eyes, legs, ankles or fingers. Lupus nephritis affects approximately 3 out of 10,000 people. In children with SLE, about half will have some form or degree of kidney involvement.