Evidence for Systemic Immunologic Activation Parameters That Distinguish Wet and Dry Forms of ARMD

Abstract

Abstract: : Purpose:To determine what immune parameters related to systemic monocytes might distinguish between wet and dry ARMD. Methods:Heparinzed blood was collected from 32 subjects with ARMD (9 dry, 23 wet), and from 10 age–matched control subjects. Phenotypic analysis of peripheral blood monocytes was accomplished by flow cytometry. Plasma levels of macrophage chemo–attractant protein (MCP–1) were determined by Enzyme–linked immunosorbent assay (ELISA). Results:HLA–DR expression levels on CD14 blood monocytes of all ARMD subjects demonstrated a positive correlation to macular drusen severity (p<0.01). Plasma levels of MCP–1 were highest for subjects with dry ARMD, compared to controls (p<0.05). The activation marker CD16 was markedly elevated on CD14 monocytes for subjects with dry ARMD compared to subjects with wet ARMD (p<0.01), and compared to normal controls (p<0.001) Conclusions:Data presented in this study are consistent with a model of ARMD that involves systemic immune activation detectable at both the cellular (monocyte) and cytokine (MCP–1) levels. These immune parameters define immunological differences between the wet and dry forms of disease, and may be useful in disease monitoring and development of effective novel therapies.

Keywords: age-related macular degeneration • inflammation • cytokines/chemokines