Hypercytokinemia in COVID-19: Tear cytokine profile in hospitalized COVID-19 patients

Abstract

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.

Keywords: COVID; Cytokine; Inflammation; Tear.

Fig. 1

Tear cytokine levels in controls and COVID-19 patients. Data are expressed as mean (pg/mL) + standard deviation (SD). * (p < 0.05); ** (p < 0.01).

Fig. 2

Cytokine differences by severity and need for treatment targeting the release of cytokines. Moderate patients are compared to severe patients. No treatment is compared to need for specific treatment. Data are expressed as mean (pg/mL) + standard deviation (SD). * (p < 0.05); ** (p < 0.01).