Circulating microRNAs targeting coagulation and fibrinolysis in patients with severe COVID-19.

Background: Coronavirus-19 disease (COVID-19) frequently causes coagulation disturbances. Data remains limited on the effects of microRNAs (miRNAs) on coagulation during COVID-19 infection. We aimed to analyze the comprehensive miRNA profile as well as coagulation markers and blood count in hospitalized COVID-19 patients.

Methods: Citrated plasma samples from 40 patients (24 men and 16 women) hospitalized for COVID-19 were analyzed. Basic coagulation tests, von Willebrand factor (VWF), ADAMTS13, blood count, C-reactive protein, and 27 miRNAs known to associate with thrombosis or platelet activation were analyzed. MiRNAs were analyzed using quantitative reverse transcription polymerase chain reaction (RT qPCR), with 10 healthy controls serving as a comparator.

Results: Among the patients, 15/36 (41%) had platelet count of over 360 × 10⁹/L and 10/36 (28%) had low hemoglobin of < 100 g/L, while 26/37 (72%) had high VWF of over 200 IU/dL. Patients had higher levels of the miRNAs miR-27b-3p, miR-320a-3p, miR-320b-3p, and miR-424-5p, whereas levels of miR-103a-3p and miR-145-5p were lower than those in healthy controls. In total, 11 miRNAs were associated with platelet count. Let-7b-3p was associated with low hemoglobin levels of < 100 g/L. miR-24-3p, miR-27b-3p, miR-126-3p, miR-145-5p and miR-338-5p associated with high VWF.

Conclusion: COVID-19 patients differentially express miRNAs with target genes involved in fibrinolysis inhibition, coagulation activity, and increased inflammatory response. These findings support the notion that COVID-19 widely affects hemostasis, including platelets, coagulation and fibrinolysis.