Impact of Comorbid Pathology and Severity of Clinical Course on Anti-infective Protection in Patients with COVID-19

Abstract

Objective — to establish and evaluate the impact of comorbid pathology and the severity of the clinical course on the activity of anti-infective protection in patients with coronavirus disease 2019 (COVID-19), based on the analysis of the absolute and relative counts of major immune cell populations in peripheral blood. Materials and methods. A cross-sectional prospective study was conducted involving 204 patients with COVID-19-associated pneumonia of mild, moderate and severe stages. The cohort included 106 (51.97 %) women and 98 (48.03 %) men, with an average age of (55.93 ± 8.75) years. Anti-infective ­protection was studied using comprehensive clinical blood analysis, including the count of major immune-competent cells. Patients were categorised into groups based on comorbi­dity, taking into account the predominant concurrent pathology at the time of examination (endocrine, cardiovascular or other). Results and discussion. More severe COVID-19 cases were characterised by leukopenia, relative and absolute granulocytopenia, neutropenia, a slight hyporegenerative nuclear shift to the right and a reduction in the number of segmented neutrophils by 24.63—34.72 % (p ≤ 0.047—0.009) and eosinophilic granulocytes by 52.94—70.59 % (p ≤ 0.004—0.001). This was accompanied by relative and absolute agranulocytosis due to lymphocytosis (by 20.10—63.33 %; p ≤ 0.05—0.003) and monocytosis (by 40.0—74.12 %; p ≤ 0.046—0.049), indicating an active inflammatory infectious process of viral etiology against a background of decreased resistance and increased activity of the lymphocyte-macrophage link with the beginning of the formation of specific immune protection (cellular and humoral response to coronavirus intervention). Mild cases of COVID-19 showed a higher absolute count of peripheral blood granulocytes (by 48.25 %; p = 0.018), neutrophils, particularly segmented neutrophils and eosinophilic granulocytes, compared to moderate and severe cases (by 32.36—53.18 % (p ≤ 0.049—0.01) and 3.4 times (p ≤ 0.005—0.002)) and the lowest content of monocytes (by 35.41—42.57 %; p ≤ 0.049—0.046). In cases with concurrent endocrine and cardiological pathologies against a background of a more severe clinical course of COVID-19, immunoinflammatory changes intensified due to absolute and relative leukopenia, neutrophilic granulocytopenia, neutropenia, with the presence of relative lymphocytosis and monocytosis, and normal ESR indicators, confirming the inflammatory process of viral etiology, which, in the absence of treatment, may tend to form post-COVID and/or long-term effects of COVID-19 with multisystem involvement. Conclusions. The study found an enhancement of the immunoinflammatory response and an increase in the depletion of cellular factors of non-specific anti-infective protection with the progression of the clinical manifestations of COVID-19, particularly against the backdrop of comorbid endocrine and/or cardiological pathology.