Morphological Changes in Blood Cells as Indicators for Disease Progression in COVID-19

Abstract

BACKGROUND: COVID-19 as a pandemic has caused an alarming increase in mortality and morbidity. Viral-induced morphologic changes in the peripheral blood cells are well characterized in certain infections and can direct diagnostic workup to ensure timely therapeutic intervention. This study describes the morphological changes of blood cells in various stages of COVID disease. MATERIALS AND METHODS: A total of thousand COVID-positive patients admitted in the tertiary care center were taken for the study. They were classified as mild, moderate, and severe based on the clinical criteria suggested by World Health Organization. Peripheral smears of the patients were analyzed, and the morphological changes in various blood cells were correlated with the disease stage and coagulation parameters. RESULT(S): The study demonstrated significant morphological changes in the blood cells of COVID patients during the course of disease progression and during the onset of COVID-associated coagulopathy. Leukocytosis, neutrophilia, and toxic changes in neutrophils were seen in the severe stage of the disease and in COVID coagulopathy suggesting these are important indicators of disease severity. Activated lymphocyte was found to be the most common morphological presentation seen in all patients irrespective of the disease stage, whereas plasmacytoid lymphocytes were an important finding in severe-stage disease. Schistocytes an important finding in any other coagulopathy was present only in 1% of cases of COVID coagulopathy. CONCLUSION(S): The study demonstrated significant morphological changes in the blood cells of COVID-positive patients during the course of disease progression. Comprehensive daily complete blood count and peripheral smear examination should be undertaken in patients hospitalized with COVID-19 to predict potential clinical deterioration and signs of disease progression. These morphological changes in peripheral smear can be used as one of the factors indicating disease progression which can formulate for further evaluation. Since follow-up and post-COVID morphological examination were not done, additional research in this aspect can shed light on the clinical categorization of COVID patients based on the morphological findings.Copyright © 2023 Journal of Applied Hematology Published by Wolters Kluwer - Medknow.