Pathological findings and morphologic correlation of the lungs of autopsied patients with SARS-CoV-2 infection in the Brazilian Amazon using transmission electron microscopy

• Published in: Revista da Sociedade Brasileira de Medicina Tropical
• Main Authors: Monique Freire Santana, Rebecca Augusta de Araújo Pinto, Bruna Hilzendeger Marcon, Lia Carolina Almeida Soares de Medeiros, Thiago Barros do Nascimento de Morais, Lucas Castanhola Dias, Lorenna Pereira de Souza, Gisely Cardoso de Melo, Wuelton Marcelo Monteiro, Marcus Vinicius Guimarães Lacerda, Fernando Almeida Val, Pritesh Jaychand Lalwani, Luiz Carlos de Lima Ferreira
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sociedade Brasileira de Medicina Tropical (SBMT) 2021
• Subjects: COVID-19; Severe acute respiratory syndrome 2; Lung pathology; Electron microscopy; Diffuse alveolar damage; Postmortem evidence; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.1590/0037-8682-0850-2020; https://doaj.org/article/4ae0f58e00a640289b07cd8a8dc0391b

Abstract INTRODUCTION: Electron microscopy (EM) is a rapid and effective tool that can be used to create images of a whole spectrum of virus-host interactions and, as such, has long been used in the discovery and description of viral mechanisms. METHODS: Electron microscopy was used to evaluate the pulmonary pathologies of postmortem lung sections from three patients who died from infection with SARS-associated coronavirus 2 (SARS-CoV-2), a new member of the Coronaviridae family. RESULTS: Diffuse alveolar damage (DAD) was predominant in all three patients. The early exudative stage was characterized principally by edema and extravasation of red blood cells into the alveolar space with injury to the alveolar epithelial cells; this was followed by detachment, apoptosis, and necrosis of type I and II pneumocytes. The capillaries exhibited congestion, exposure of the basement membrane from denuded endothelial cells, platelet adhesion, fibrin thrombi, and rupture of the capillary walls. The proliferative stage was characterized by pronounced proliferation of type II alveolar pneumocytes and multinucleated giant cells. The cytopathic effect of SARS-CoV-2 was observed both in degenerated type II pneumocytes and freely circulating in the alveoli, with components from virions, macrophages, lymphocytes, and cellular debris. CONCLUSIONS: Viral particles consistent with the characteristics of SARS-CoV-2 were observed mainly in degenerated pneumocytes, in the endothelium, or freely circulating in the alveoli. In the final stage of illness, the alveolar spaces were replaced by fibrosis.