Association Of Coagulation Disturbances With Severity Of Covid-19: A Longitudinal Study

Objectives Coagulation dysfunction is an evident factor in the clinical diagnosis and treatment of patients with coronavirus disease 2019 (COVID-19), appearing even in COVID-19 patients with normal inflammation indices. Therefore, this study aimed to analyze the characteristics of coagulation function indices in COVID-19 patients to investigate possible mechanisms through the comparison of non-severe and severe COVID-19 patients. Methods We included 143 patients whose clinical characteristics, coagulation function, and other indices such as inflammatory factors were collected and compared based on disease severity. Results Activated partial thromboplastin time (APTT), D-dimer, and fibrinogen levels were evidently higher in the severe group than in the non-severe group. Among non-severe COVID-19 patients, the aforementioned indicators depicted increasing trends, but the fibrinogen level alone was higher than normal. However, in severe COVID-19 patients, values of all three indices were higher than normal. In severe COVID-19 patients, fibrinogen and D-dimer were correlated with several inflammation indices during the early stage of the disease. However, no correlation between fibrinogen and inflammatory factors was observed in non-severe COVID-19 patients at any time point. Discussion Results revealed that the hypercoagulability tendency of severe COVID-19 patients was more evident. The relationship between coagulation function and inflammatory factors showed that changes in coagulation function in severe COVID-19 patients may be related to abnormal increase in inflammatory factors at an early stage; however, in non-severe COVID-19 patients, there might be other factors leading to abnormal coagulation. Conclusion Inflammatory factors were not the only cause of abnormal coagulation function in COVID-19 patients.