Peculiarities of lung lesions in coronavirus infection: clinico-pathomorphological analysis of autopsy cases

Abstract

The aim of study is to investigate the clinical and pathomorphological features of lung lesions in fatal cases of diseases. Materials and methods. A retrospective analysis of 1036 consecutive autopsies at COVID-19 was conducted on the basis of the Lviv Regional Office for Autopsy. The diagnosis of COVID-19 was confirmed by clinical signs of viral pneumonia, nasopharyngeal smear analysis, and radiological changes. Statistical study was performed with IBM SPSS Statistics 24.0. Results. The majority of autopsy cases were elderly people over 60 years old (72.4%). The ratio of men and women was almost the same: men made up 54.1%, women 45.9%. The age of the deceased ranged from 19 to 93 years, the average age was 66.9 ± 0.4 years. Acute phase of pneumonia was diagnosed in 18.5% of cases, proliferative phase — in 18.6%, fibrotic phase — in 5.9%. And in 53.5% of cases prevailed signs of progressive fibrosis associated with exudative lesions. COVID-19 was single original cause of death in 88.7% cases. In the lungs were identified: the typical virus-induced changes in epithelial cells of the trachea, bronchi, bronchioles and alveoli (100%, n=1036); different phases of diffuse alveolar damage in majority of cases (96.5%); manifestations of innate/adaptive immunity were described; pathological changes in microvasculature (large vessel thrombi were detected in 37.9%). Conclusions. The results of our study prove that the lungs are the main target organ of the severe course of COVID-19. The combination of diffuse alveolar damage with thrombosis of pulmonary arteries of medium and small caliber causes deaths. This leads to a severe course of the disease, hypoxia and respiratory failure.