INTRODUCTION: One of the promising treatments for COVID-19 aimed at correcting the immune response and reducing the level of pro-inflammatory cytokines is the use of mesenchymal stem cells (MSCs). There is evidence that MSCs, due to various mechanisms, are able to suppress the cytokine storm in patients with COVID-19. Thus, the use of MSCs can contribute to the suppression of inflammation and the regulation of immune homeostasis in patients with severe COVID-19. OBJECTIVE: Evaluation of the effect of mesenchymal stem cell (MSC) therapy on the course of severe forms of novel coronavirus infection, accompanied by “cytokine storm”. MATERIALS AND METHODS: A prospective single-center study included 39 patients treated for coronavirus infection on the basis of the intensive care unit and, after randomization, randomly divided into control (n = 16) and study groups (n = 23). An assessment of clinical, laboratory parameters in both groups and a cytokine profile in the study group was carried out. Outcomes were compared, the incidence of complications and clinical and laboratory parameters in both groups, and the cytokine profile in the study group. RESULTS: The use of MSCs in patients with severe forms of COVID-19 affected the outcomes of the disease, the duration of stay on mechanical ventilation, the course of acute respiratory distress syndrome (ARDS) (an increase in the oxygenation index in patients of the study group by 5, 7 days from administration in comparison with the control group). CONCLUSIONS: In patients treated with MSCs, there was a significant decrease in a number of pro-inflammatory cytokines.

Portal hypertension is the major consequences of liver cirrhosis and is accompanied by pathologic increase in portal blood flow resistance. As portal hypertension develops that results in formation of vessel's collaterals and arterial vasodilatation. Hyperdynamic alternations become more significant due to hyporesponsiveness to vasoconstrictors and increased shunts formation with autonomic neuropathy. This combination of liver failure and portal hypertension leads to the hyperdynamic circulatory state partly owing to simultaneous vasodilatation of splanchnic and peripheral arterial vessels. So hyperdynamic circulatory syndrome is a late complication of portal hypertension due to liver cirrhosis. The main features of hyperdynamic circulatory syndrome are high cardiac output, increased heart rate and total blood volume coupled with decreased total systemic vascular resistance. Some of these cardiovascular changes are reversible after liver transplantation what show pathophysiological significance of portal hypertension. In this paper, we aimed to review pathophysiology and features of hyperdynamic syndrome that are well-known and directly related to portal hypertension (varices, ascites, hepatic encephalopathy and hepatorenal syndrome), while others are more rare and therefore further investigations are necessary (portopulmonary hypertension, cirrhotic cardiomyopathy).