Pathogenesis Clues from the Early Clinical Presentation of 300 Hospitalized COVID-19 Patients

Background: The global spread of the 2019 coronavirus disease (COVID-19) has lasted more than half a year. Except for the gene sequence and viral structure of SARS-CoV-2, its clinical characteristics, pathological mechanisms and corresponding measures have not been fully revealed. We aimed to speculate about the possible pathological mechanism from the early clinical manifestations of patients with COVID-19. Methods: : The onset symptoms, laboratory examinations and CT findings on admission of 300 patients in two wards of Wuhan Third Hospital from January 28 to March 15 were analyzed retrospectively. Results: : There was no difference in incidence between men and women, but women were hospitalized later after onset. Upper respiratory symptoms and sputum were rare. The incidence of fever was 71%. Blood lymphocyte counts were decreased significantly on admission and were related to the severity of the disease. In moderate patients without hypoxia, thrombocytopenia occurred in 12.37%, CRP rose in 64.43%, BUN was elevated in 20.62%, creatinine rose in 17.53%, D-dimer was elevated in 74.74%, and creatine kinase and α-hydroxybutyrate dehydrogenase were elevated in 45.36% and 54.12% of patients, respectively. Early CT showed a small amount of infiltration in the subpleural and lateral zones of the lung and thickening of the interlobular septum. Approximately 5 days later, infiltration was worse in some of the patients, and the proportion of involvement of the affected lung was negatively correlated with the lymphocyte count. Conclusions: : There was no sex difference in patients with SARS-CoV-2 infection. Alveolar cells and T lymphocytes may be the main targets of the virus, and apoptosis may be the primary mechanism of pathogenesis. The virus entering the lung may be transmitted through lymph or blood vessels rather than directly dispersing through the respiratory tract. Early damage to multiple organs may be caused by the immune response.