Serum Elastin Derived Peptides in Age–related Macular Degeneration

Abstract

Abstract: : Purpose: Dysregulation of extracellular matrix (ECM) plays an important role in the pathogenesis of age–related macular degeneration. Elastin is a fibrous protein constituent of the ECM. Degradation of elastin is detected by the presence of serum elastin derived peptides (S–EDP) in circulation. This study estimated S–EDP in subjects with age related macular degeneration (AMD) compared to age–matched controls. Methods: Estimation of S–EDP was done using competitive ELISA in 56 patients with AMD compared to 15 age–matched controls. Subjects with AMD were classified into two groups: early age–related maculopathy (ARM n=30) and neovascular AMD (n=26). The ELISA made use of solubilised α–elastin from human aorta and polyclonal antibodies to this antigen. Results: S–EDP was significantly higher in AMD (mean 29.6 ±3.95 ng/ml) compared to controls (mean 15.4 ± 2.76 ng/ml, p<0.05). Subjects with neovascular AMD had higher levels of S–EDP (mean 36.2 ± 23.1 ng/ml) compared to early disease (mean 23.9 ±9.07 ng/ml, p<0.05). Conclusions: Systemic elastin turnover is increased in patients with AMD and the level of S–EDP increases with severity of AMD. Increased S–EDP may be a risk factor or a by–product of AMD but this requires further investigation. Further studies with serial determinations of S–EDP are needed to confirm whether these circulating peptides may be useful predictors of CNV formation.

Keywords: age-related macular degeneration • proteolysis • clinical laboratory testing