Inflammatory monocytes accumulate in atrophic age-related macular degeneration

Abstract

Purpose: The chemokine/chemokine receptor axis CCL2/CCR2 has been shown to mediate CD16 positive inflammatory monocyte recruitment in a number of neurodegenerative disorders. We have studied the recruitment of inflammatory cells in age-related macular disease (AMD).

Methods: CD16, CCR2 and CD18 immunochemistry were performed on macular sections of donor tissues with GA lesions (n=10) and age matched control eyes (n=5). Quantification of subretinal CD16+ positive cells was performed.

Results: Control eyes did not contain CD16+ inflammatory monocytes. In AMD numerous CD16+CCR2+CD18+ cells were found in the subretinal space in and adjacent to the atrophic lesion.

Conclusions: Our results show that GA is associated with an infiltration with CD16+CCR2+CD18+ inflammatory monocytes. Sustained presence of inflammatory monocytes has been shown to play an important detrimental role in neurodegenerative diseases such as multiple sclerosis, experimental autoimmune encephalitis, and stroke. A similar mechanism might contribute to photoreceptor degeneration in AMD.

Keywords: 412 age-related macular degeneration • 557 inflammation • 554 immunohistochemistry