What caused COVID-19’s death? Why does hypoxemia occur in patients with severe COVID-19 at a later stage? What are the target cells for COVID-19 infection? Chinese medical experts have explored the etiology of COVID-19 disease.
The COVID-19 virus pneumonia etiology diagnosis research team led by Wang Chaofu, director of the Department of Pathology, Ruijin Hospital, Shanghai Jiaotong University, found the clues to the truth of the disease in the autopsy of severe COVID-19 death cases. Pathophysiology and provide relevant pathological basis for subsequent treatment.
Wang Chaofu said in an interview on the 27th that the research team found that the cause of COVID-19 death was severe lung injury leading to respiratory failure and functional failure of other important organs. Compared with other previously reported SARS and MERS, the formation of mucus plugs in the lower respiratory tract and the aggregation and activation of alveolar macrophages are special features of COVID-19; alveolar macrophages expressing ACE2 (cell surface receptor), Become a target cell for COVID-19 infection.
Experts announce results of heavy COVID-19 etiology study, including 2 special features
On February 17, Wang Chaofu, as the leader of the COVID-19 etiology research expert team appointed by the National Health Commission, led the team to the front line in Wuhan. The team consists of 6 experts who carry out COVID-19 pathology and etiological diagnosis research. They are all elites with long-term work in the clinical and research fields of pathology and imaging, with rich work experience and professional skills. Professor Wang Chaofu has won the Kaiyuan Award from Shanghai Jiaotong University, and is an outstanding pathologist and a well-loved university professor.
Professor Wang Chaofu, who has returned to Shanghai, said in an interview on the 27th that the study found that the most affected organ of COVID-19 pathological change was the lung, which showed mixed pathological changes of exudation, metamorphosis and proliferation, including diffuse alveolar damage, Alveolar septal fibrous tissue hyperplasia and pulmonary consolidation caused by fibrous tissue hyperplasia.
Based on research, extensive mucus secretion and exudation have significantly impaired lung ventilation and ventilation function in patients, which may be one of the mechanisms of late hypoxemia in patients with severe COVID-19. In COVID-19 patients, activated macrophages may play an important role in a series of severe “inflammatory factor storms.” According to reports, in the course of severe and advanced acute respiratory distress syndrome (ARDS), the conversion between classical activated macrophages and alternative activated macrophages may be an important cause of lung inflammation and fibrosis.
It is understood that tocilizumab has been added to immunotherapy in the “New Coronavirus Pneumonia Diagnosis and Treatment Scheme (Trial Version 7)”. Researchers believe that tocilizumab is used as an inhibitor to block the key cytokines induced by COVID-19 virus infection in the inflammatory storm, effectively reducing the damage to the lung tissue and multiple organs of patients.
According to reports, the Wang Chaofu team published related latest research in the form of preprinted papers on the ResearchSquare platform sponsored by Springer Nature, reporting the results of the pathological anatomy of severe COVID-19.