Dynamic features of the humoral immunity in patients with acute coronary syndrome depending on the content of B lymphocytes with the CD3<sup>-</sup>CD19<sup>+</sup>CD5<sup>+</sup> phenotype, who have and have not C

The purpose of the work was to study the dynamic features of the humoral immunity in patients with acute coronary syndrome depending on the content of B lymphocytes with the CD3-CD19+CD5+ phenotype, who had and did not have COVID-19. We analyzed data on humoral immunity in men aged 40 to 65 years with acute coronary syndrome, who had and did not have COVID-19, depending on the content of B lymphocytes with the CD3-CD19+CD5+ phenotype. All patients underwent coronary angiography with further stenting of the coronary arteries. The values of lymphocytes with the CD45+CD3-CD19+ phenotype and the presence or absence of COVID-19 previously were taken into account. Using the flow cytometry method, 2 groups were gated using the pan-leukocyte marker CD45+: the subgroup of B lymphocytes CD3-CD19+CD5+ and the subgroup of B lymphocytes CD3-CD19+CD5-, B lymphocytes (CD45+CD3-CD19+). Levels of total IgA, IgG, IgM, C1-inhibitor, C3a and C5a complement components by enzyme immunoassay. After coronary artery stenting, B lymphocytes (CD3-CD19+CD5+) significantly increased in the group of people with COVID-19, with initially low levels of these cells (p 0.01) and normal cells (p 0.05). In individuals who had COVID-19 and did not have this disease, with initially decreased CD3-CD19+CD5+ cells, B lymphocytes (CD45) increased significantly (p 0.001 and p 0.05, respectively) over time (p 0.05+CD3-CD19+), B lymphocytes (CD3-CD19+CD5-). In the group of patients who recovered from COVID-19 with normal CD3-CD19+CD5+ cells, the relative number of B-lymphocytes decreased over time (p 0.01) (CD45+CD3-CD19+) and CD3-CD19+CD5- cells. In persons who had previously suffered from COVID-19, with increased CD3-CD19+CD5+ cells, the number of B-lymphocytes (CD45+) significantly (p 0.05) decreased over time CD3-CD19+), in those who did not have COVID-19 with high above-mentioned cells, immunoglobulin A significantly (p 0.05) increased. The most severe clinically was the group of people with low CD3-CD19+CD5+B cells and COVID-19 in the anamnesis.