Platelet-driven coagulopathy in COVID-19 patients: in comparison to seasonal influenza cases

Background: One year into the coronavirus diseases 2019 (COVID-19) pandemic we analyzed the blood coagulopathy in severe and non-severe COVID-19 patients and linked to those of influenza patients for a comparative study.

Methods: We reported 461 COVID-19 patients and 409 seasonal influenza patients admitted at separated medical centers. With their demographic data and medical history, hematological profiles with coagulation characters were emphasized, and compared between two cohorts before and after treatment.

Results: For 870 patients included in this study, their median age was (64.0, 51.0-76.0), and among them 511 (58.7%) were male. Hypertension, diabetes, cardiovascular diseases, and bronchitis constituted the leading comorbidities. Upon hospital admission blood test results differentiated COVID-19 patients from influenza cases, and for COVID-19 patients, leukocytosis, neutrophilia, lymphocytopenia, and thrombocytopenia were associated with disease severity and mortality. In addition, COVID-19 cohort demonstrated a prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT), increased INR, shortened thrombin time and decreased fibrinogen, compared to those in influenza cohort, leaving D-dimer levels indistinguishably high between both cohorts. Platelet hyperreactivity in COVID-19 is more evident, associated with worse hyper-inflammatory response and more refractory coagulopathy. For severe COVID-19 patients administered with anticoagulants, bleeding incidence was substantially higher than others with no anticoagulant medications.

Conclusions: Comparison of coagulation characteristics between COVID-19 and influenza infections provides an insightful view on SARS-CoV-2 pathogenesis and its coagulopathic mechanism, proposing for therapeutic improvement.