Tear and aqueous humour cytokine profile in primary open-angle glaucoma

Abstract

Purpose: To evaluate the concentrations of pro-inflammatory cytokines in tear and aqueous humour of patients with primary open-angle glaucoma (POAG), relative to healthy controls.

Method: Tear and aqueous humour samples were collected from 29 healthy controls and 27 POAG patients. Twenty-seven inflammatory cytokines were analysed: interleukin (IL)-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL9, IL-10, IL-12, IL-13, IL-15, IL-17, eotaxin, fibroblast growth factor (FGF) basic, granulocyte colony-stimulating factor, granulocyte-monocyte colony-stimulating factor, interferon (IFN)-γ, interferon gamma-induced protein, monocyte chemo-attractant protein-1, macrophage inflammatory protein (MIP)-1α, MIP-1β, platelet-derived growth factor, regulated on activation normal T cell expressed and secreted, tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF).

Results: In tear samples of glaucoma patients, an increase in IL-4, IL-12, IL-15, FGF-basic and VEGF was observed, as well as a decrease in MIP-1a relative to the control group (p < 0.05). IL-5, IL-12, IL-15, IFN-γ and MIP-1a were significantly higher in aqueous humour of glaucoma eyes (p < 0.05). A poor correlation between cytokine levels in tear and aqueous humour was observed.

Conclusion: The different profiles of inflammatory marker expression of patients with POAG and healthy controls confirm the inflammatory activity of the pathology, indicating that some of them could be used as potential biomarkers of this disease.

Keywords: cytokine; glaucoma; inflammation; primary open-angle glaucoma.