Monocytosis in rational empirical antibacterial therapy in moderate forms of COVID-19

Abstract

Microbiologically confirmed bacterial co-infection occurs in 1.2%–7% of hospitalized patients with COVID-19. The study of rational approaches to empirical antibacterial therapy (ABT) of SARS-CoV-2 virus-induced pneumonia continues. Glucocorticoid (GCS) therapy, the main method for pathogenetic treatment of moderate forms of CОVID-19, can lead to the development of neutrophilic leukocytosis. The criterion for the differential diagnosis of leukocytosis could be determining the quantity of peripheral blood monocytes. Assessing the significance of identifying the monocyte quantity can serve as an additional criterion for assigning empirical ABT in the treatment of pneumonia caused by the new coronavirus infection. The aim of the study was to identify the characteristics of glucocorticoid-induced leukocytosis in patients with moderate COVID-19. The study included 86 patients with a confirmed diagnosis of COVID-19 (ICD codes: U07.1, U07.2) of moderate severity. The patients were divided into 2 groups. The comparison group consisted of 40 patients who were prescribed ABT after the manifestation of leukocytosis on the background of glucocorticoid therapy. The control group included 46 people who were not prescribed ABT after the manifestation of leukocytosis on the background of glucocorticoid therapy and until the end of their stay in the hospital. We compared the parameters of the clinical blood tests (the absolute number of white blood cells, neutrophils and monocytes (×109/L)) on days 3, 6 and 9 from the start of GCS therapy. As a result, on the 3rd day, both groups had neutrophilic leukocytosis (>9.0×109/L) and absolute monocytosis (>0.8×109/L). There was a statistically signif icant decrease in the absolute number of white blood cells, neutrophils and monocytes by days 6 and 9, compared with day 3 from the start of glucocorticoid therapy. When comparing blood parameters between the groups, there was no statistically significant difference in the number of cells on the 3rd, 6th and 9th day of GCS therapy (p>0.05). Glucocorticoid-induced leukocytosis is associated with absolute monocytosis. The administration of ABT in response to the occurrence of leukocytosis in this study did not affect the change in the level of white blood cells. At the same time, a likely factor in reducing these indicators was a decrease in the daily dosage of corticosteroids.