Characteristics of Peripheral Blood Cells in COVID-19 Patients Revealed by a Retrospective Cohort Study (preprint)

ABSTRACT

Background Peripheral hematological changes in severe COVID-19 patients may reflect the immune reaction during SARS-CoV-2 infection. Characteristics of peripheral blood cells as early signals were needed to be investigated for clarifying its associations with the fatal outcomes in COVID-19 patients. Methods A retrospective cohort study was performed and the hospitalized COVID-19 patients were recruited in wards of Tongji Hospital (Wuhan, China). Characteristics of peripheral blood cells in survivors and non-survivors were analyzed. Also the comparison among patients with different level of eosinophils was performed. Results198 patients were included in this study, of whom 185 were discharged and 13 died in hospital. Compared to the survivors, counts of lymphocytes, monocytes, eosinophils and basophils were significantly decreased in non-survivors. According to the level of eosinophils, patients were divided into low EOS group (< 0.02×109/L) and normal EOS group (≥ 0.02×109/L). Patients in the low EOS group showed a significantly higher fever compared to normal EOS group. The proportion of patients in low EOS group who used glucocorticoids increased significantly than the other group. Death rate in the low EOS group was higher and no patient death in normal EOS group. Moreover, positive correlation was found between the counts of lymphocytes and eosinophils in patients with glucocorticoids use but not in patients without the treatment. Conclusions Hematological changes differed between survivors and non-survivors with COVID-19. Lymphopenia and eosinopenia could serve to predict the poor prognosis of COVID-19 patients. Initial counts of eosinophils may guide us in usage of glucocorticoids for COVID-19 treatment.