Cytokine status and significant increase of IL-6 and sIL-6R in the aqueous humor of diabetic cataract patients revealed by quantitative multiplexed assays

Objective This study aimed to investigate inflammatory cytokine expression profiles in the aqueous humor (AH) of diabetic cataract (DC) patients. Methods A quantitative multiplexed antibody assay was performed to measure the expression levels of 40 inflammatory cytokines in AH samples from DC and age-related cataract (ARC) patients. Bioinformatics analysis was used to examine the functions of the cytokines. Enzyme-linked immunosorbent assays (ELISAs) and western blots were performed to verify the data. Results The multiplexed antibody assay revealed that the expression levels of IL-6, sIL-6R, IL-17A, IL-8, MCP-1, TNF-β, RANTES, TIMP-1, and TIMP-2 were higher in the AH of DC patients compared with ARC patients. However, IL-1ra and IL-1a expression levels were lower in the DC patient AH samples. Pathway analysis indicated that IL-6 and sIL-6R belong to the class I helical cytokine family, which is associated with many biological functions. ELISA and western blot results confirmed that IL-6R and IL-6 expression levels were significantly higher in DC patients compared with ARC patients. Conclusions Our results revealed the status of 40 inflammatory cytokines in the AH by quantitative multiplexed assays. Additionally, IL-6 and sIL-6R were expressed markedly higher in DC compared with ARC, which may play critical roles in DC pathophysiology.