PULMONARY PATHOLOGY OF NEW CORONAVIRUS DISEASE (COVID- 19). THE PRELIMINARY ANALYSIS OF POST-MORTEM FINDINGS

Abstract

Background. Currently, the patho- and morphogenesis of a new coronavirus infection (COVID-19) is being studied in depth. Conducting a comparative analysis of the morphological changes in the lungs of deceased patients at various time periods after the onset of the first clinical symptoms. Clinical and morphological comparisons should help to increase qualified medical care for patients in the resuscitation profile and reduce hospital mortality. The aim of the study was to formulate a working hypothesis of a conceptual scheme of clinical and morphological forms of development of a new coronavirus infection (COVID-19). Methods. An analysis of 80 fatal cases was carried out in the COVID-center of the Federal Research Clinical Center of FMBA of Russia. Along with the assessment of macro- and microscopic changes in the respiratory tract, an additional histochemical staining according to van Gieson was applied and immunohistochemical studies were performed to assess the condition of the lungs with COVID-19. Results. The revealed features of diffuse alveolar damage in case of a new coronavirus infection (COVID-19) made it possible to present a working hypothesis of the pathomorphogenesis of specific acute coronavirus (COVID-19) alveolitis (pneumonitis). It goes through 3 stages-forms: fulminant, persistent and fibrotic. Each stage is conditionally limited by certain time parameters and is characterized by certain morphological characters. Dysregulatory activation of monocytic phagocytes, development of generalized microthrombosis, persistent signs of the exudative phase, pathological repair, progressive intraalveolar and interstitial fibrosis are the main links in the pathomorphogenesis of specific acute coronavirus (COVID-19) alveolitis (pneumonitis).