Proteomic and genomic biomarkers for age-related macular degeneration

Toward early detection of susceptibility to age-related macular degeneration (AMD), we quantified plasma carboxyethylpyrrole (CEP) oxidative protein modifications and CEP autoantibodies by ELISA in 916 AMD and 488 control donors. Mean CEP adduct and autoantibody levels were elevated in AMD plasma by ∼60 and ∼30%, respectively, and the odds ratio for both CEP markers elevated was ∼3-fold greater in AMD than in control patients. Genotyping was performed for AMD risk polymorphisms associated with age-related maculopathy susceptibility 2 (ARMS2), high-temperature requirement factor A1 (HTRA1), complement factor H (CFH), and complement C3. The AMD risk predicted for those exhibiting elevated CEP markers and risk genotypes was 2- to 3-fold greater than the risk based on genotype alone. AMD donors carrying the ARMS2 and HTRA1 risk alleles were the most likely to exhibit elevated CEP markers. Receiver operating characteristic curves suggest that CEP markers alone can discriminate between AMD and control plasma donors with ∼76% accuracy and in combination with genomic markers, provide up to ∼80% discrimination accuracy. CEP plasma biomarkers, particularly in combination with genomic markers, offer a potential early warning system for predicting susceptibility to this blinding disease.