Features of immune status in patients with acute coronary syndrome with and without COVID-19, depending on the level of B1 lymphocytes

The aim of our study was to evaluate the blood cell indices and phagocytic activity of neutrophils in persons with acute coronary syndrome, depending on their history of COVID-19 infection.

The study involved 65 males aged 35 to 65 years with acute coronary syndrome (acute myocardial infarction and unstable angina pectoris). All patients underwent coronary angiography and stenting of the coronary arteries within 3 days from the terms of admission to the hospital. The following clinical examination were carried out: a general blood test by a standardized method on a hematological analyzer Medonic M20 (Sweden). Of immunological indices, the phagocytic activity of neutrophils was assessed. Spontaneous and induced NBT test of neutrophils was determined by light microscopy using light microscopy (Olimpus, Japan). The phagocytic activity of neutrophils was recorded by their ability to absorb latex particles. B1 lymphocytes were determined using flow cytometry.

All patients, depending on the content of B1 lymphocytes and the presence or absence of COVID-19 in previous history, were divided into 6 groups: patients with COVID-19 and those with reduced (group 1), normal (group 2), or elevated number of B1 lymphocytes (group 3). The patients who did not have COVID-19 were also classified into those with low (group 4), normal (group 5), or elevated B1 lymphocytes (group 6). The numbers of leukocytes in routine blood test were significantly higher, and the average corpuscular volume of hemoglobin was lower in the patients who have undergone COVID-19. Platelet counts were higher in post-COVID-19 patients, being maximal at normal B1 lymphocytes. The largest number of monocytes was recorded in patients with COVID-19 and normal B1 lymphocytes, and the minimal content of monocytes was registered in patients of group 4. The highest number of granulocytes was observed in individuals who did not have COVID-19, with reduced B1 lymphocytes. Thrombocytocrit was the highest in group 2 patients. The activity and intensity of neutrophil phagocytosis was lower in individuals with a history of COVID-19 and elevated B1 lymphocytes. The phagocytic number of neutrophils was minimal in those patients without COVID-19 who had low B1 lymphocytes. The maximal spontaneous HBT activity was recorded in individuals with high B1 lymphocytes and a history of COVID-19, and the minimal values have been recorded in those with low B1 lymphocytes and previous COVID-19. NBT spontaneous index was also the highest in patients of the 3^rd group. The minimal NBT-induced activity and index were noted in group 1. The most severe patients were in groups 1 and 2. In group 1, 50% were diagnosed with acute myocardial infarction, stent thrombosis was diagnosed in 2 patients, four patients deceased. Among patients with normal B1 cell contents and a history of COVID-19, 2 patients died, 2 patients had stent thrombosis, 65% had acute myocardial infarction. These groups had higher platelet levels and lower HBT activity, both spontaneous and induced.

In patients with acute coronary syndrome and prior COVID-19, in comparison with persons without a history of COVID-19, there is an increased number of leukocytes, platelets, a decrease in the activity and intensity of neutrophil phagocytosis, spontaneous and stimulated NBT activity, which was most pronounced in patients with low B1 lymphocytes. The most clinically severe patients were found in the group of people who had undergone COVID-19 and had low B1 lymphocytes.