Lupus nephritis

Definition

Alternative Names

Causes

Lupus nephritis is one complication of systemic lupus erythematosus (SLE). It is related to the autoimmune process of lupus, where the immune system produces antibodies (antinuclear antibody and others) against body components. Complexes of these antibodies and complement accumulate in the kidneys and result in an inflammatory response.

Lupus causes various disorders of the internal structures of the kidney, including interstitial nephritis, mesangial GN, membranous GN, membranoproliferative GN, diffuse proliferative GN, and others.

It often causes nephrotic syndrome (excessive protein excretion) and may progress rapidly to renal failure. There is progressive azotemia (the accumulation of nitrogenous waste products in the bloodstream) and urinary abnormalities including protein and blood in the urine.

Lupus nephritis affects approximately 3 out of 10,000 people. Systemic lupus erythematosus is most common in women, especially those 20 to 40 years old. It has a familial tendency, with a higher incidence in blacks. It may be related to other autoimmune disorders including rheumatoid arthritis and scleroderma. It has been known to be triggered by pregnancy in some cases.

In children with SLE, about half will have some form or degree of kidney involvement.