The aim of this study is to analyze the concentrations of cytokines in tear of hospitalized COVID-19 patients compared to healthy controls. Tear samples were obtained from 41 healthy controls and 62 COVID-19 patients. Twenty-seven cytokines were assessed: interleukin (IL)-1b, 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 basic, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), interferon (IFN)-γ, interferon gamma-induced protein, monocyte chemo-attractant protein-1, macrophage inflammatory protein (MIP)-1a, MIP-1b, platelet-derived growth factor (PDGF), regulated on activation normal T cell expressed and secreted, tumor necrosis factor-α and vascular endothelial growth factor (VEGF).
In tear samples of COVID-19 patients, an increase in IL-9, IL-15, G-CSF, GM-CSF, IFN-γ, PDGF and VEGF was observed, along with a decrease in eotaxin compared to the control group (p < 0.05). A poor correlation between IL-6 levels in tear and blood was found. IL-1RA and GM-CSF were significantly lower in severe patients and those who needed treatment targeting the immune system (p < 0.05). Tear cytokine levels corroborate the inflammatory nature of SARS-CoV-2.

本研究的目的是分析与健康对照相比住院的 COVID-19 患者泪液中细胞因子的浓度。泪液样本取自 41 名健康对照者和 62 名 COVID-19 患者。评估了 27 种细胞因子：白细胞介素 (IL)-1b、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、碱性成纤维细胞生长因子、粒细胞集落刺激因子（G-CSF）、粒细胞单核细胞集落刺激因子（GM-CSF）、干扰素（IFN）- γ，干扰素γ诱导蛋白，单核细胞化学引诱蛋白-1，巨噬细胞炎症蛋白（MIP）-1a，MIP-1b，血小板衍生生长因子（PDGF），调节激活正常T细胞表达和分泌，肿瘤坏死因子-α和血管内皮生长因子（VEGF）。在 COVID-19 患者的泪液样本中，与对照组相比，观察到 IL-9、IL-15、G-CSF、GM-CSF、IFN-γ、PDGF 和 VEGF 的增加，以及嗜酸细胞趋化因子的减少 (p < 0.05)。发现泪液和血液中 IL-6 水平之间的相关性很差。重症患者和需要针对免疫系统进行治疗的患者的 IL-1RA 和 GM-CSF 显着降低 (p < 0.05)。泪液细胞因子水平证实了 SARS-CoV-2 的炎症性质。