Endothelial dysfunction in children with SARS-CoV-2-associated pneumonia and its dependence on the activity of the infectious-inflammatory process

One of the key pathogenetic mechanisms of COVID-19 is endothelial dysfunction, which enhances prothrombotic phenomena, endotheliitis, and multiorgan immunothrombosis. The mechanisms of endothelial damage in children remain insufficiently studied. Aim: to determine the levels of endothelial dysfunction in children with SARS-CoV-2-associated pneumonia and to analyze its relationships with clinical and laboratory indicators of the activity of the infectious and inflammatory process. Materials and methods. The Main group consisted of 160 children with SARS-CoV-2-associated pneumonia and 40 healthy children (Control group). The Main group was divided depending on gender, age, disease severity, levels of C-reactive protein (CRP), and procalcitonin. To assess endothelial dysfunction, the level of endothelin-1 and vascular endothelial growth factor (VEGF) in blood serum was determined. Results. The values of VEGF and endothelin-1 were the highest in patients with severe pneumonia. The values of laboratory markers of endothelial dysfunction were significantly higher with higher levels of CRP in children of the Main group by 31.95% and 33.14% for endothelin-1 and VEGF, respectively. A positive medium-strength relationship was established between the values of fibrinogen and CRP with VEGF levels; a weak positive relationship between the levels of VEGF and procalcitonin; fibrinogen and endothelin-1 levels. A probable medium-strength positive relationship was established between the values of endothelin-1 and VEGF, with the levels of interleukins (IL) 1, 6. Conclusions Children of the Main group have endothelial dysfunction, as evidenced by increased levels of endothelin-1 and VEGF. These values were associated with disease severity, CRP levels, and gender. VEGF levels were highest in patients with severe pneumonia. There was a moderate positive association between laboratory markers of endothelial dysfunction, such as endothelin-1 and VEGF, and IL-1 and IL-6 levels.