Factor H

Factor H is a protein that in humans is encoded by the CFH gene. It is involved in the regulation of the complement system, which is a part of the immune system that enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promotes inflammation, and attacks the pathogen's cell membrane.

Function

Factor H functions as a cofactor in the inactivation of C3b by Factor I, another protein in the complement system. This prevents the complement system from causing unnecessary damage to host tissues and keeps the system focused on foreign substances.

Structure

The structure of Factor H is composed of 20 short consensus repeat (SCR) domains. Each SCR is about 60 amino acids in length and is stabilized by two disulfide bonds.

Clinical significance

Mutations in the CFH gene are associated with a variety of diseases, including atypical hemolytic uremic syndrome (aHUS), age-related macular degeneration (AMD), and Membranoproliferative glomerulonephritis (MPGN).

Atypical hemolytic uremic syndrome

In atypical hemolytic uremic syndrome, mutations in the CFH gene lead to a decrease in the regulation of the complement system on cell surfaces, leading to cell damage and the clinical symptoms of the disease.

Age-related macular degeneration

In age-related macular degeneration, certain variants of the CFH gene are associated with an increased risk of developing the disease. The exact mechanism by which these variants contribute to the disease is still under investigation.

Membranoproliferative glomerulonephritis

In Membranoproliferative glomerulonephritis, mutations in the CFH gene can lead to uncontrolled activation of the complement system in the kidneys, leading to kidney damage and disease.

See also

• Complement system
• Atypical hemolytic uremic syndrome
• Age-related macular degeneration
• Membranoproliferative glomerulonephritis