Dynamics of lymphocyte content in peripheral blood in children with coronavirus infection during treatment

The issues of the pathogenesis of the new coronavirus infection in children of different ages, despite the end of the pandemic, remain relevant. The issue related to the development of delayed reactions after SARS-CoV-2 infection requires further study. The search for markers of the risk of developing post-COVID reactions is also relevant. Purpose: Study of the content of peripheral blood lymphocytes in children with SARS CoV-2 infection in the dynamics of treatment. Materials and Methods: A retrospective analysis of 106 medical records of patients aged 2 to 14 years hospitalized from October 2021 to December 2022 with a confirmed diagnosis of COVID-19 was conducted. Two groups were formed: Group 1 — children aged 2 to 7 years; Group 2 — children aged 8 to 14 years. The levels of lymphocytes in the peripheral blood of children were analyzed over the course of treatment. In each group, the study was conducted four times with an interval of one week. Statistical processing of the obtained results was carried out using the Statistika 10.0 software package. Wilcoxon and Mann-Whitney criteria were used in statistical processing. Results: It was found that 63.71% of children in the younger age group and 73.33% of older children had relative lymphopenia upon admission to the hospital. During treatment, the dynamics of changes in lymphocyte content were similar regardless of age, but differed depending on the initial level of lymphocytes. In groups with lymphopenia, the average values of the indicator increased significantly over time and practically corresponded to the normative values before discharge from the hospital. However, when analyzing individual values of lymphocyte content in the dynamics of treatment in all subgroups, some children had relative lymphopenia. Conclusion. Perhaps a decrease in the level of lymphocytes not only at the onset of the disease, but also the presence of lymphopenia with a significant improvement in the clinical condition (regardless of their initial level) can be a criterion for the risk of developing post-COVID reactions in children who have suffered SARS-CoV-2 infection in the late period.

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