Association of monocyte count alterations with COVID-19 severity

ABSTRACT

Background: COVID-19 caused by SARS-CoV-2 has led to an ongoing pandemic with massive global health and socioeconomic consequences. Monocytes are recruited under pathological conditions like viral infections to the affected tissue to defend the organism against invading pathogens and to aid in efficient resolution of inflammation. Some studies had suggested a significant decrease of monocytes in COVID-19 patients with severe or critical disease whereas some others suggested monocytosis. Aim of the Study To find the association of Monocyte count alterations with the severity of COVID-19. Methods: This is a retrospective study conducted in Dept of Respiratory Medicine, KIMS Hospital and Research Centre, Bengaluru. A total of 1000 COVID patients were taken in the order of their admission from Jan-May 2021. Monocyte count in the blood at the time of admission was collected. Ethical clearance was obtained from the institutional ethical committee. Results: Higher monocyte count was seen in the younger age group, particularly in Category B COVID-19 patients. Statistically significant association was found between low monocyte count and the disease severity and mortality in patients with COVID-19. Conclusion: It is inferred that monocytes proliferate to eliminate the viruses in mild patients, while the loss of monocytes in the critical patients suggest that innate immunity might be suppressed to a certain extent in critical COVID-19. Deviation in monocytes count from the normal is a valuable discriminator for diagnosis of COVID-19 and suitable anticipator of overall spectrum of adverse consequences.