Long-term pathological changes in lungs after COVID-19

World literature is paying increasing attention to the long-term course of COVID-19 and symptoms that appear after the acute coronavirus infection. The symptoms, functional state of the lungs, and the X-ray changes are assessed. Nevertheless, post-COVID lung histology has not been described yet.

The aim of this article is to study the long-term pathological changes in the lungs after acute COVID-19. Methods. We analyzed autopsy lung material from 19 deceased who had COVID-19. The average age of the deceased was 68.82 ± 14.6 years. All patients were found to have IgG to SARS-CoV-2. The median time to death following viral interstitial pneumonia was 72 days. Results. The causes of death and thrombotic complications (infarctions of various organs and venous thrombosis) were analyzed. Histological examination revealed thrombosis of small pulmonary arteries and capillaries of interalveolar septa, microinfarctions, hemorrhages, foci of organizing pneumonia, and nonspecific interstitial pneumonia.

Conclusion. The first assessment of histological changes in human lungs showed that the most common post-COVID pathologic changes are microcirculation disorders combined with small areas of acute lung damage. The obtained data are essential for understanding the pathogenesis of post-COVID syndrome, necessitate diagnostic of microvasculature disorders using laboratory tests, scintigraphy, and CT imaging, as well as search for the therapeutic strategies.

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