Blood cell counts and lymphocyte subsets of patients admitted during the COVID-19 pandemic: a prospective cohort study

Abstract

Aberrant blood cell counts, most prominently lymphopenia, have been identified as markers of the degree of severity of coronavirus disease 2019 (COVID‐19) (Terpos et al , 2020; Yang et al , 2020; Wan et al , 2020; Wang et al , 2020; Zhao et al , 2020). However, most of these studies lack comparison to a COVID‐19 negative, contemporary control group. Additionally, the longitudinal composition and dynamics of lymphocyte subsets in COVID‐19 patients are insufficiently characterized.