Altered Expression of CD46 and CD59 on Leukocytes in Neovascular Age-Related Macular Degeneration

PURPOSE: To investigate the expression of the complement regulatory proteins CD46, CD55, and CD59 on peripheral leukocytes in neovascular age-related macular degeneration (AMD). DESIGN: Prospective, case-control study. METHODS: Thirty-five unrelated patients with neovascular AMD and 30 control individuals were included in this case-control study. All participants were subjected to a structured interview and detailed imaging (autofluorescence, digital funduscopy, spectral-domain optical coherence tomography, and fluorescein and indocyanine green angiography in patients suspected of having neovascular AMD) was performed. Fresh ethylenediamine-tetraacetic acid blood was obtained and stained with monoclonal antibodies. Using flow cytometry, the percentage of CD14(+) monocytes, CD45(+) lymphocytes, and CD45(+) granulocytes positive for CD46, CD55, and CD59 was determined in patients with neovascular AMD and was compared with that of controls. RESULTS: We found that the expression of CD46 and CD59 was significantly lower on CD14(+) monocytes in patients with neovascular AMD compared with controls (P = .0070). A significantly lower expression of CD46 on lymphocytes was observed in patients with fibrosis compared with patients without fibrosis (P = .010). CONCLUSIONS: Our study suggests that neovascular AMD is associated with an inadequate regulation of the complement system, supporting current evidence on the role of complement dysregulation in the pathogenesis of AMD. (Am J Ophthalmol 2012;154:193-199. (C) 2012 by Elsevier Inc. All rights reserved.)