Multiplex Cytokine Analysis of Aqueous Humor from the Patients with Chronic Primary Angle Closure Glaucoma

Abstract

Purpose: To compare the levels of cytokines and growth factor in aqueous humor of the patients with chronic primary angle closure glaucoma (PACG) and cataract.

Methods: Aqueous humor samples were collected from 19 chronic PACG patients and compared with 14 nonglaucomatous controls presenting for cataract surgery. The levels of 27 cytokines and growth factors were measured in the aqueous samples using multiplex bead immunoassay and compared across groups.

Results: Significantly higher levels of interleukin (IL)-8 (p < 0.001), eotaxin (p < 0.001), interferon gamma-induced protein (IP)-10 (p < 0.001) and macrophage inflammatory protein-1-beta (MIP-1β; p < 0.001) were observed in aqueous of chronic PACG patients compared to controls. In comparison to controls, significantly lower levels of IL-9 (p = 0.001), IL-17 (p < 0.001), tumor necrosis factor-alpha (TNF-α; p < 0.001), granulocyte-macrophage colony-stimulating factor (GM-CSF; p < 0.001), and IL-5 (p = 0.001) were observed in chronic PACG eyes. All other assayed cytokines-IL-1β, interleukin-1 receptor antagonist (IL-1rα), IL-6, IL-7, IL-10, IL-12, IL-13, IL-15, fibroblast growth factor-basic (FGF-basic), granulocyte colony-stimulating factor (G-CSF), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1-alpha (MIP-1α), and vascular endothelial growth factor (VEGF) -showed no significant difference between the groups.

Conclusions: These results suggest that the aqueous cytokine levels of chronic PACG eyes differ significantly from nonglaucomatous eyes. This is the first study reporting significantly increased levels of eotaxin, MIP-1β, and IP-10 and lower levels of TNF-α, IL-5, IL-9, IL-17, and GM-CSF in chronic PACG patients, suggesting a plausible role of these inflammatory cytokines in its pathogenesis.

Keywords: Aqueous humor; chemokines; chronic PACG; cytokines; multiplex assay.