Paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired, life-threatening disease of the blood characterized by destruction of red blood cells by the complement portion of the immune system. This destructive process is a result of a defect in the formation of surface proteins on the red blood cell, which normally function to inhibit such immune reactions. Since the complement cascade attacks the red blood cells throughout the circulatory system, the hemolysis is considered an intravascular hemolytic anemia. The major cause of death PNH is thrombosis.