Cellular cooperations at different times of COVID-19 pneumonia

Objective: to assess the severity of inflammatory cell infiltration and expression of CD3, CD45, CD15, CD68 proteins at different times of COVID-19 pneumonia. Material for morphological and immunohistochemical studies was obtained during autopsy of 80 deceased. The immediate cause of death in patients with COVID-19 was acute respiratory distress syndrome (45 %), thrombosis of the branches of the pulmonary artery (30 %), multiple organ failure (25 %). Computer morphometry was used, the staining area coefficient was determined, followed by statistical analysis. The role of immunocompetent cells at different stages of the development of COVID-19 pneumonia has been little studied. The performed morphoimmunohistochemical study of the lungs with COVID-19 indicates a significant disruption of cellular cooperation of immunocompetent cells (CD3, CD45) with a predominance of macrophages (CD68) in the late stages of the disease development (2240 days). Probably, activation of the macrophage link of immunity can further initiate the development of pneumofibrosis and neoangio-genesis.