Analysis of plasma hemostasis and the role of microvesicles in the coagulation process in patients with COVID-19

BACKGROUND: Coagulopathies in COVID-19 are an important aspect in the pathophysiological mechanisms, clinical picture of the disease, and occurrence of delayed complications. AIM: To study plasma hemostasis using turbidimetry, thromboelastography, and the role of microvesicles in the coagulation process in patients with COVID-19. MATERIAL AND METHODS: The study used blood samples from patients of the temporary infectious diseases hospital based on the State Autonomous Healthcare Institution “Republican Clinical Hospital of the Ministry of Health of the Republic of Tatarstan” in Kazan (n=213) in the period from June to August 2020. Patients were divided into two groups according to the severity of the disease: the first group — moderate COVID-19 (n=138), the second group — severe COVID-19 (n=75). Patients were treated according to the protocols of the Temporary Methodological Recommendations of the Ministry of Health of the Russian Federation, version 7. The blood of healthy donors (n=20) was used as a control group. Plasma hemostasis was assessed using dynamic turbidimetry (measured lag period — Lag, polymerization rate — V, maximum optical density at a given wavelength — Amax) and thromboelastography (determined coagulation activation time — R). Statistical processing of the results was performed using IBM SPSS Statistics 26.0. The groups were compared using the nonparametric Mann–Whitney U-test. Statistical processing of the results following standart normal distribution was performed using the Student's t-test. Differences were considered significant at p 0.05. RESULTS: Severe COVID-19 was characterized by an increase in the lag period (9.4±0.8 min relative to the control 6.2±1.2 min; p 0.0001), a decrease in the polymerization rate (1.12±0.71 OD units/s relative to the control 3.93±2.3 OD units/s; p 0.0001) and a decrease in the maximum optical density of the clot (0.576±0.17 OD units relative to the control 1.625±0.433 OD units; p 0.0001). In moderate cases, a shortening of the lag period was noted (3.8±1.1 min relative to the control 6.2±1.2 min; p=0.0004), the maximum optical density of the clot was lower than the control (1.412±0.351 OD units at 1.625±0.433 OD units, respectively; p=0.0007). In patients with moderate disease severity, a 1.6-fold reduction in coagulation activation time was noted relative to the control group. In patients with severe disease, coagulation activation time was increased by 1.5 times relative to the control. After adding microvesicles to the samples, this parameter decreased by 2.12 times in patients with a moderate course of the disease (16.9±1.1 min and 8±0.6 min; p 0.0001), and by 1.44 times in patients with a severe course of the disease (10.8±0.9 min and 7.5±0.5 min; p 0.0001). CONCLUSION: Moderate COVID-19 is characterized by signs of hypercoagulation, which can lead to the development of thrombotic complications; severe disease is accompanied by hypocoagulation, which contributes to hemorrhagic complications.