Blood expression levels of chemokine receptor CCR3 and chemokine CCL11 in age-related macular degeneration: a case-control study

Background: Dysregulation of the CCR3/ CCL11 pathway has been implicated in the pathogenesis of choroidal neovascularisation, a common feature of late age-related macular degeneration (AMD). The aim of this study was to investigate the expression of CCR3 and its ligand CCL11 in peripheral blood in patients with neovascular AMD. Methods: Patients with neovascular AMD and healthy controls were included. Blood samples were obtained and prepared for flow cytometry to investigate the expression of CCR3. Levels of CCL11 were measured in plasma using Cytometric Bead Array. Differences between the groups were tested using Kruskal-Wallis test and Mann-Whitney U test. Results: Patients (n = 83) with neovascular AMD and healthy control persons (n = 114) were included in the study. No significant difference in the expression of CCR3 was found on CD9+ granulocytes when comparing patients suffering from neovascular AMD with any of the control groups. We did not find any alteration in CCL11 levels in patients among the age matched groups. There was no correlation between expression of CCR3/ CCL11 and clinical response to treatment with anti-vascular endothelial growth factor (VEGF). Conclusion: Our results do not suggest a systemic alteration of the CCR3/ CCL11 receptor/ligand complex in patients with neovascular AMD.