Definition of Membranoproliferative GN II:

Membranoproliferative glomerulonephritis (GN) type II is a kidney disorder causing decreased kidney function because of inflammation and changes in the tissues of the internal kidney structures.

Causes, incidence, and risk factors:

Glomerulonephritis is inflammation of the glomeruli, the inner structures of the kidney that help filter waste and fluids from the blood to form urine.

Membranoproliferative GN II is a form of glomerulonephritis. It is caused by an abnormal immune response. Deposits of antibodies build up in a part of the kidneys called the glomerular basement membrane. This membrane helps filter waste and extra fluid from the blood.

The changes in this membrane lead disrupt the body's ability to filter urine. Protein and fluid leak out of the blood vessels into body tissues, leading to edema. Nitrogen waste products may accumulate in the blood (azotemia) because of poor kidney functioning.

Membranoproliferative GN II is much less common than Membranoproliferative GN I and occurs in both males and females, usually under age 30. It also tends to get worse faster than does membranoproliferative GN I.

The disorder is often progressive and may result in chronic renal failure.