Pulmonary Artery Vasa Vasorum Damage in Severe COVID-19–Induced Pulmonary Fibrosis

Abstract

Background: COVID-19 patients exhibit higher incidence of thrombosis in arteries and veins, including those in lungs. Vasa vasorum, which support large blood vessels, have shown involvement in these pathologic processes. Methods: To further explore the extent of microvascular damage caused by COVID-19 infection, we examined resected main, right, or left pulmonary artery specimens from patients undergoing bilateral lung transplantation for COVID-19– or non–COVID-19–induced pulmonary fibrosis compared with organ donors by histologic and immunohistologic analyses. Results: Vasa vasorum density was found to be higher in specimens procured from patients with COVID-19 and associated with pulmonary artery hypertension compared with lung transplant donors. In addition, we found immunothrombosis within vasa vasorum in specimens from COVID-19 patients with more immune infiltration, including CD15+, CD44+, and CD68+ cells. Conclusions: These findings reveal that COVID-19 affects the vasa vasorum of pulmonary arteries and suggest that infection may lead to large-vessel dysfunction and organ failure.