New Coronavirus Infection as a Risk Factor for The Development of Long-Term Consequences of The Disease in Children

COVID-19 in children causes significant changes in the immune and coagulation systems, which persist in the post-COVID period, which can lead to the formation of adverse consequences.

Objective of the study was to determine the risk factors for the development of long-term consequences of a new coronavirus infection in children.

Materials and methods . The assessment of the state of the immune and coagulation systems in children in the acute and long-term period, as well as the analysis of the health status of children who have had COVID-19 ( n = 132). Research was conducted to analyze the immune status of children with COVID-19 and their level of protection against vaccinepreventable infections ( n = 60).

Results . During the acute period of COVID-19, children’s immunograms showed an increase in the level of activated T-lymphocytes ( p < 0.001), a decrease in serum IgM and IgG ( p < 0.050), and a high level of CIC ( p < 0.050). In addition, patients over 8 years of age had leukopenia ( p < 0.05), lymphocytosis ( p < 0.05), neutropenia ( p < 0.001), and decreased neutrophil absorption activity ( p < 0.05). In the post-COVID period, there was a reduced level of immunoglobulins M and G, neutropenia, an increased level of activated T-lymphocytes, and a high level of CIC. Evaluation of coagulogram indicators at the debut of NCI showed the presence of reduced platelet aggregation ( p < 0.010), thrombin time ( p < 0.001), increased concentration of fibrinogen and D-dimer ( p < 0.001), euglobulin lysis time and high content of RFMC. After SARS-CoV-2 infection, increased values of fibrinogen, D-dimer, euglobulin lysis time, RFMC remained.

Discussion . The acute period of NCI was characterized by activation of the cellular and phagocytic links, insufficient levels of humoral protection, high levels of circulating immune complexes, and age-related differences. Changes in hemostasis indicators at the onset of COVID-19 were procoagulant and persisted in the post-COVID period. The identified laboratory changes and health abnormalities provide a basis for identifying risk groups among those who have recovered from the disease.

Conclusion . Persistent abnormalities in the immune, coagulation, and health systems of children during the post-COVID period, as well as a low level of protection against infectious diseases and vaccine-preventable infections, are predisposing factors for the development of adverse consequences and allow for the formation of risk groups among children based on their development.

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