Multiplex cytokine levels of aqueous humor in acute primary angle-closure patients: fellow eye comparison

Abstract

Background: The existing literature contains no information regarding inflammatory cytokine expression in unilateral acute primary angle-closure (APAC) affected eyes and fellow eyes with primary angle closure suspect (PACS). To measure levels of various inflammatory cytokines in the aqueous humor (AH) of APAC affected eyes and fellow eyes with a diagnosis of PACS (18 unilateral APAC eyes and 18 fellow eyes with PACS), and determine the underlying correlation between them.

Methods: The total levels of 12 cytokines including granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-6, IL-8, monocyte chemotactic protein (MCP)-1, MCP-3, macrophage-derived chemokine (MDC), macrophage inflammatory protein (MIP)-1β, and vascular endothelial growth factor (VEGF) etc. were assessed using the multiplex bead immunoassay technique. The level of cytokines in different groups was analyzed by a 2-related-samples nonparametric test. Data on patient demographics, preoperative intraocular pressure (IOP), number of glaucoma medications, as well as several ocular biological parameters were also collected for correlation analysis.

Results: The APAC patients had significantly higher levels of G-CSF, IL-6, IL-8, MCP-1, MCP-3, MDC, MIP-1β, and VEGF in the AH samples from unilateral APAC affected eyes than in fellow eyes with PACS (all P < 0.05). The cytokines showed positive correlations between each other (P < 0.0071).

Conclusions: Cytokine networks in the AH may have critical roles in the progression of APAC. Thus, different cytokine expression in both eyes of the same patient may help us to understand the different pathology in APAC and PACS.

Fig. 1

Differences of cytokines in APAC with PACS. Scatterplots showing distribution levels of G-CSF, IL-6, IL-8, MCP-1, MCP-3, MDC, MIP-1β, and VEGF in aqueous humor from unilateral acute primary angle-closure (APAC) affected eyes and fellow eyes with primary angle-closure suspect (PACS). Two-related-samples nonparametric test was performed between groups, and a significant difference was accepted at P < 0.05. The solid lines indicate median concentrations. In the APAC patients, the levels of G-CSF (P = 0.001), IL-6 (P = 0.000), IL-8 (P = 0.000), MCP-1 (P = 0.000), MCP-3 (P = 0.008), MDC (P = 0.009), MIP-1β (P = 0.001), and VEGF (P = 0.035) in AH samples from unilateral APAC affected eyes were significantly higher than those from fellow eyes with PACS