Ultrastructural Reorganization of Endotheliocytes of Pulmonary Blood Capillaries in COVID-19.

The ultrastructural organization endotheliocytes of pulmonary blood capillaries in COVID-19 was studied on autopsy material using electron microscopy. Swelling of the cytoplasm and mitochondria with destruction of the cristae, dilation of the Golgi complex cisternae, a decrease in the volume density of the luminal and basal caveolae and free transport vesicles, an increase of the rough endoplasmic reticulum, as well as the presence of elements of coronavirus replication (reticulovesicular structures, zippered endoplasmic reticulum, electron-dense particles in the Golgi cisternae, and vacuoles with viral particles) were revealed. Further studies of the intracellular mechanisms used by the virus to replicate could help to develop antiviral drugs for the treatment of the new coronavirus infection.