Phenotype of peripheral blood monocytes in young patients with COVID-19 and developed cardiovascular pathology

Introduction. The COVID-19 pandemic has revealed a high incidence of extrapulmonary complications, with cardiovascular and cerebrovascular events being the most prevalent. Of particular concern is the rising number of severe cardiovascular pathologies in young patients without prior cardiac history.

Aim. To investigate the phenotypic characteristics of peripheral blood monocytes in young patients (18–45 years) with COVID-19 and subsequent cardiovascular pathology (acute myocardial infarction or acute cerebrovascular accident).

Materials and methods. A prospective study included 202 participants: 28 apparently healthy individuals (control group), 143 patients with laboratory-confirmed SARSCoV-2 infection without complications, 19 with acute myocardial infarction, and 12 with acute cerebrovascular accident. Immunophenotyping was performed using multiparameter flow cytometry to assess the expression of CD14, HLA-DR, CD11b, CD206, FcγRII, TNFR1, TNFR2, CD68, TRAIL, and TGFβ1. Statistical analysis was carried out using the nonparametric Kruskal-Wallis test.

Results. Patients with COVID-19 exhibited significantly reduced HLA-DR expression on monocytes–79.0 (76.0; 83.7)% compared to 93.4 (90.9; 96.6)% in controls (p < 0.001)–alongside a progressive increase in the alternative activation marker CD206 (p < 0.001). A TNF-α receptor imbalance was observed: selective elevation of TNFR1 specifically in acute myocardial infarction and consistently increased TNFR2 expression across all patient groups relative to controls (p < 0.001). Levels of TRAIL and TGFβ1 were significantly elevated in all post-COVID patient groups, reaching their highest values in those with vascular complications (p < 0.001).

Conclusion. In young patients, SARSCoV-2 infection induces persistent dysregulation of the monocyte phenotype, characterized by reduced expression of major histocompatibility complex class II molecules, a shift toward a reparative-fibrotic profile, and an imbalance between pro- and anti-inflammatory receptors. These phenotypic alterations may serve as differential immunological markers associated with the development of acute cardiovascular and cerebrovascular complications.

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