Neutrophil extracellular traps in the pathogenesis of obstetric complications in COVID-19 (brief review)

Introduction. In the pathogenesis of the new coronavirus infection (COVID-19), innate cellular elements of the immune system are of great importance, among which special attention is paid to neutrophils and the mechanisms of their death – netosis, which leads to the formation of extracellular DNA traps. Neutrophil extracellular traps play an important role in the development of endothelial dysfunction and thrombotic disorders, which not only complicates the course of COVID-19 infection, but also causes severe obstetric complications that increase the risk of maternal and infant mortality. This review describes possible mechanisms for the formation of neutrophil extracellular traps, as well as their role in the pathogenesis of COVID-19.Materials and methods. An analysis of Russian (eLibrary) and foreign (PubMed) literature was carried out with a search depth of 2010-2021.Results. The pathogenesis of COVID-19 is directly related to the uncontrolled progression of systemic inflammation, which changes the innate immune response in the form of functional maladaptation and premature death of neutrophils with the formation of neutrophil extracellular traps. The neutrophils that were transformed by netosis play a key role in the development of thrombotic disorders of the microvasculature, which leads to the development of life-threatening complications such as acute respiratory distress syndrome and multiple organ failure, which increases the mortality of patients with COVID-19 infection. During pregnancy, increased formation of neutrophilic extracellular traps is the cause of hemodynamic disturbances of the fetoplacental complex, placental disorders and endothelial dysfunction, concomitant with the development of preterm labor and preeclampsia, which increases the risk of postpartum hemorrhage, maternal morbidity and mortality. Therefore, new data on neutrophil extracellular traps and mechanisms of formation may lead to a reconsideration of the pathogenesis of thrombotic disorders in pregnant women with COVID-19 infection, which is important for further management of pregnancy.