Detection of SARS-CoV-2 Viral Genome and Viral Nucleocapsid in Various Organs and Systems.

While considerable attention has been devoted to respiratory manifestations, such as pneumonia and acute respiratory distress syndrome (ARDS), emerging evidence underlines the significance of extrapulmonary involvement. In this study, we examined 15 hospitalized patients who succumbed to severe complications following SARS-CoV-2 infection. These patients were admitted to the Sibiu County Clinical Emergency Hospital in Sibiu, Romania, between March and October 2021. All patients were ethnic Romanians. Conducted within a COVID-19-restricted environment and adhering to national safety protocols, autopsies provided a comprehensive understanding of the disease's multisystemic impact. Detailed macroscopic evaluations and histopathological analyses of myocardial, renal, hepatic, splenic, and gastrointestinal tissues were performed. Additionally, reverse transcription-quantitative polymerase chain reaction (rt-qPCR) assays and immunohistochemical staining were employed to detect the viral genome and nucleocapsid within the tissues. Myocardial lesions, including ischemic microstructural changes and inflammatory infiltrates, were prevalent, indicative of COVID-19's cardiac implications, while renal pathology revealed the chronic alterations, acute tubular necrosis, and inflammatory infiltrates most evident. Hepatic examination identified hepatocellular necroinflammatory changes and hepatocytic cytopathy, highlighting the hepatic involvement of SARS-CoV-2 infection. Splenic parenchymal disorganization was prominent, indicating systemic immune dysregulation. Furthermore, gastrointestinal examinations unveiled nonspecific changes. Molecular analyses detected viral genes in various organs, with immunohistochemical assays confirming viral presence predominantly in macrophages and fibroblasts. These findings highlighted the systemic nature of SARS-CoV-2 infection, emphasizing the need for comprehensive clinical management strategies and targeted therapeutic approaches beyond respiratory systems.