Complement Activation Levels Are Related to Disease Stage in AMD

Area of Science:

• Ophthalmology
• Immunology
• Genetics

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss.
• The complement system, a part of innate immunity, plays a crucial role in AMD pathogenesis.
• Genetic factors significantly influence AMD risk and progression.

Purpose of the Study:

• To investigate complement activation levels across different stages of AMD.
• To determine the impact of genetic polymorphisms in complement genes on AMD progression.
• To explore the relationship between complement activation, AMD stage, and genetic variants.

Main Methods:

• Studied 797 AMD patients and 945 controls.
• Categorized AMD into five stages: early, intermediate, central geographic atrophy, active choroidal neovascularization, and inactive choroidal neovascularization.
• Assessed complement activation via the systemic C3d/C3 ratio and analyzed 18 complement gene polymorphisms.

Main Results:

• Complement activation levels significantly differed across AMD stages.
• The C3d/C3 ratio was elevated in intermediate AMD and central geographic atrophy compared to controls.
• Specific polymorphisms in CFH and CFB genes correlated with increased complement activation.

Conclusions:

• AMD progression is associated with increasing complement activation, especially in genetically susceptible individuals.
• Findings may inform patient selection and treatment timing for complement inhibitor therapies.
• Further prospective studies are required to validate these results.