Abstract：
Hypercoagulability and reduced fibrinolysis are well-established complications associated with COVID-19. However, the timelines for the onset and resolution of these complications remain unclear. The aim of this study was to evaluate, in a cohort of COVID-19 patients, changes in coagulation and fibrinolytic activity through ROTEM assay at different time points during the initial 30 days following the onset of symptoms in both mild and severe cases. Blood samples were collected at five intervals after symptoms onset: 6-10 days, 11-15 days, 16-20 days, 21-25 days, and 26-30 days. In addition, fibrinogen, plasminogen, PAI-1, and alpha 2-antiplasmin activities were determined. Out of 85 participants, 71% had mild COVID-19. Twenty uninfected individuals were evaluated as controls. ROTEM parameters showed a hypercoagulable state among mild COVID-19 patients beginning in the second week of symptoms onset, with a trend towards reversal after the third week of symptoms. In severe COVID-19 cases, hypercoagulability was observed since the first few days of symptoms, with a tendency towards reversal after the fourth week of symptoms onset. A hypofibrinolytic state was identified in severe COVID-19 patients from early stages and persisted even after 30 days of symptoms. Elevated activity of PAI-1 and alpha 2-antiplasmin was also detected in severe COVID-19 patients. In conclusion, both mild and severe cases of COVID-19 exhibited transient hypercoagulability, reverted by the end of the first month. However, severe COVID-19 cases sustain hypofibrinolysis throughout the course of the disease, which is associated with elevated activity of fibrinolysis inhibitors. Persistent hypofibrinolysis could contribute to long COVID-19 manifestations.
摘要：
高凝状态和纤维蛋白溶解减少是与COVID-19相关的公认并发症。然而,这些并发症的发生和解决时间仍不清楚.这项研究的目的是评估，在一组COVID-19患者中，在轻度和重度病例出现症状后的最初30天内，通过ROTEM测定在不同时间点的凝血和纤溶活性变化。在症状发作后每隔5次收集血液样本：6-10天，11-15天,16-20天,21-25天,26-30天此外,纤维蛋白原，纤溶酶原,测定PAI-1和α2-抗纤溶酶活性。在85名参与者中，71%患有轻度COVID-19。20个未感染的个体被评估为对照。ROTEM参数显示轻度COVID-19患者在症状发作的第二周开始出现高凝状态，症状出现第三周后有逆转的趋势。在严重的COVID-19病例中，从症状出现的最初几天开始观察到高凝状态，症状发作的第四周后有逆转的趋势。在早期阶段的严重COVID-19患者中发现了低纤溶状态，甚至在症状出现30天后仍持续存在。在严重的COVID-19患者中也检测到PAI-1和α2-抗纤溶酶活性升高。总之,COVID-19的轻度和重度病例均表现为一过性高凝状态，在第一个月底恢复。然而,严重的COVID-19病例在整个疾病过程中持续纤溶不足，这与纤维蛋白溶解抑制剂的活性升高有关。持续的低纤维蛋白溶解可能导致长期的COVID-19表现。
