C1-inhibitor

C1-inhibitor (or C1-INH) is a protein found in the fluid part of your blood. It controls (inhibits) the C1 complement proteins. Complement proteins are part of your immune system that fight infections and kill cancer cells. C1-INH also controls the blood clotting system.

Function

C1-INH helps to regulate the amount of fluid in your body and the flow of blood through your blood vessels. A lack of C1-INH can cause hereditary angioedema, a medical condition that causes swelling in various parts of the body, including the face, hands, feet, and internal organs.

Role in Disease

Deficiency of C1-INH can result in hereditary angioedema (HAE), a rare disorder that is characterized by recurrent episodes of severe swelling (angioedema). The most common areas of the body to develop swelling are the limbs, face, intestinal tract, and airway.

Treatment

Treatment for HAE includes C1-INH replacement therapy. This treatment involves infusing the C1-INH protein into the patient's bloodstream. This can be done at a hospital or at home with a home infusion kit.

See Also

• Complement system
• Hereditary angioedema
• Protein
• Blood