Role of microvesicles and netosis in coagulopathy in patients with SARS-CoV-2 infection: a randomized clinical trial

BACKGROUND: The high incidence of thrombotic complications in patients with SARS-CoV-2 infection significantly worsens the prognosis of the disease. The primary issue is limited comprehension on the mechanisms by which systemic inflammation, neutrophil activation, extracellular neutrophil traps, and microvesicle-mediated hemostasis disorders are interconnected. AIM: This study aimed to investigate the link between microvesicles and extracellular neutrophil traps and the occurrence of coagulopathies in patients with SARS-CoV-2 infection. The quantitative and qualitative characteristics of these phenomena were assessed based on the severity of the patients’ condition. METHODS: The study included 213 patients with SARS-CoV-2 infection (138 patients with moderate disease and 75 with severe disease) and 20 healthy donors. The patients underwent blood chemistry, coagulation, and hematology tests. A quantitative analysis of microvesicles was performed using flow cytometry with monoclonal antibodies specific for surface markers (CD45, CD3, CD14, CD15, and CD61). The interaction of microvesicles with extracellular neutrophil traps was observed by confocal microscopy (Leica TCS SP5) using fluorescent labels (DAPI, FITC, APC, and PE) and subsequently analyzed for colocalization using a LAS AF package. Statistical analysis was conducted using the Student’s t-test, Spearman’s correlation coefficient, and linear regression methods. RESULTS: The patients with moderate SARS-CoV-2 infection had hypercoagulation (fibrinogen, 4.8 [4.00; 5.60] g/L; D-dimer, 0.78 [0.30; 1.28] mg/L), with increased levels of neutrophil-derived (CD15⁺, 53.34% ± 6.92%) and platelet-derived (CD61⁺, 59.74% ± 11.22%) microvesicles. Tissue factor-enriched filamentous extracellular neutrophil traps with microvesicles were identified. The severe cases were associated with decreased levels of neutrophil-derived (CD15⁺, 10.32% ± 4.29%) and platelet-derived (CD61⁺, 20.9% ± 6.01%) microvesicles, thrombocytopenia (139.5 [104.25; 177.75] × 10⁹/L), hypocoagulation (international normalized ratio: 2.60 [2.32; 3.58]), and CD62⁺-positive aggregates. CONCLUSION: Microvesicles and extracellular neutrophil traps play a key role in dysregulated hemostasis in patients with SARS-CoV-2 infection. Early hypercoagulation is mediated by their procoagulant activity, and severe cases are associated with decreased levels of peripheral microvesicles, which is indicative of consumptive coagulopathy.