PROFILE OF CIRCULATING MICROVESICLES AS A PROGNOSTIC TOOL IN COVID-19

 COVID-19 is an infectious disease caused by the SARS-CoV-2 virus and has been responsible for the morbidity and mortality of millions of people worldwide since 2019. Its rapid spread and potential severity, especially in risk groups, have made the search for complementary laboratory prognostic tools a key issue and a great challenge for science and medicine. To characterize the profile of circulating microvesicles (MVs) as a prognostic factor in COVID-19, samples from 39 patients with COVID-19 of both genders, aged between 30 and 85 years were enrolled in the study and evaluated in 4 timepoints (Days 0, 7, 14, and 21 days after hospital admission). Thirty-two individuals were also included to compose a healthy control group. MVs were measured by flow cytometry using Cytoflex S cytometer, and labeled with Annexin-V and specific cellular biomarkers against MVs subsets. This study was submitted and approved by the Ethics Committee: C.A.A.E. 13936619.7.0000.5091. There was a significant increase in total MVs in the COVID-19 group compared to healthy controls, mainly related to increased numbers of neutrophil (CD66⁺) and endothelial (CD51/61⁺) cell-derived MVs. Moreover, at admission, there was a significant decrease in the number of monocyte (CD14⁺), T lymphocyte (CD3⁺), and platelet-derived (CD41⁺) MVs in the COVID-19 group compared to healthy controls. Considering the clinical outcome of the COVID-19 patients, there was a significant increase in the total MVs and the number of neutrophil and erythrocyte-derived (CD235a⁺) MVs in the death group compared to the discharge group. Discriminant univariate analysis achieved 88% of accuracy in differentiating COVID-19 patients from healthy individuals by using total MVs and neutrophil, monocyte, and T lymphocyte-derived MVs, as well as 77% of accuracy in discriminating COVID-19 patients according to the clinical outcome based on total MVs and neutrophil-derived MVs. Finally, the classification proposed by a tree decision built after multivariate analysis demonstrated a 28% chance of death in patients with increased number of neutrophil and monocyte-derived MVs. These findings suggest that MVs can play an important role as biomarkers and can be used as a promising tool for prognostic evaluation in COVID-19 patients.