Increased proinflammatory cytokines in tears correspond with conjunctival SARS-CoV-2 positivity in symptomatic COVID-19 patients
Anna Niedźwiedź, Miłosz Kawa, Ewa Pius‐Sadowska, Agnieszka Kuligowska, Alicja Ziontkowska-Wrzałek, Dawid Wrzałek, Marta P. Wiącek, Miłosz Parczewski, Andrzej Ossowski, Grażyna Zielińska, Krzysztof Safranow, Krzysztof Kozłowski, Bogusław Machaliński, Anna Machalińska
Abstract
Tear fluid cytokine levels may serve as biomarkers of innate immune system response against SARS-CoV-2 infection. Therefore, our aim was to analyze panel of selected inflammatory cytokines in tears of COVID-19 patients in relation to presence of SARS-CoV-2 viral load in conjunctival secretions. In this study concentrations of TNF-α, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, GM-CSF, and IFN-γ were determined by a magnetic bead assay in tear film collected from 232 symptomatic COVID-19 patients. SARS-CoV-2 ocular infection was confirmed based on positive conjunctival swab-based RT-PCR testing. Viral RNA in conjunctival sac was detected in 21 patients (9%). No relation between presence and the duration of ophthalmic symptoms and SARS-CoV-2 infection detected in conjunctival secretions was found. The tear film concentrations of IFN-γ, TNF-α, IL-5, IL-8 and GM-CSF were found to be significantly greater among patients with positive conjunctival swab results as compared to the group negative for SARS-CoV-2 in conjunctival sac. Our current data depict a group of inflammatory mediators in human tears, which may play a significant role in ocular pathology of SARS-CoV-2 conjunctival infection.