Native Endogenous Fluorescence Imaging Detects Vascular Occlusions in Patients with COVID-19

Abstract

Background: A number of histopathological reports showed the presence of widespread thrombosis and associated morphology in pulmonary vessels of patients with COVID-19. Later, we identified vascular occlusions with neutrophils and neutrophil extracellular traps (NETs), as major components, in autopsy tissue from patients with COVID-19.Methods: We, here investigated 109 lung specimens from 17 patients with COVID-19 and compared them with 11 lung specimens from two patients who succumbed to pulmonary embolism and acute cardiac. Healthy lung specimens from four patients served as controls. We studied these autopsy lung specimens using immunohistochemistry and native endogenous fluorescence.Findings: We present a label-free imaging technique using native endogenous fluorescence that enables the visualization of occluded vessels. We demonstrate that native endogenous fluorescence identified occluded vessels in tissue specimens from patients with COVID-19.Interpretation: Label-free detection of occluded vessels enabled the detection of affected occluded vessels in lung specimens of patients with COVID-19 where the occluding components showed varying contents of neutrophil-derived materials.Funding Statement: Deutsche Forschungsgemeinschaft (DFG), EU, Volkswagen-StiftungDeclaration of Interests: All authors have no conflicts of interests to declare.Ethics Approval Statement: An institutional approval from each local Ethical Committee was obtained (permit #193_13B; permit # 174_20B; EK 092/20; EK 119/20; EK 460/20).