High levels of miR-146a-5p in COVID-19 patients are associated with

Background: Bacterial coinfections in COVID-19 patients present significant clinical challenges, particularly in severe cases. Previous studies have highlighted the role of microRNAs (miRNAs) in regulating immune responses, with miR-146a-5p and miR-21-5p implicated in inflammation and immune modulation. This study examines the effect of bacterial coinfections on the expression levels of these miRNAs in patients with severe COVID-19. Methods: We conducted a cohort study involving Mexican mestizo patients ≥18 years hospitalized with severe COVID-19, confirmed via PCR testing. Patients were categorized based on the presence or absence of bacterial coinfection, determined through bronchial aspirate or sputum culture. Blood samples were collected at admission and after 15 days of hospitalization to measure the relative expression levels of miR-146a-5p and miR-21-5p. Additionally, an Results: Patients with bacterial coinfection were older (43 vs. 41 years, p = 0.046) and had a higher BMI than those without (29.40 vs. 27.51 kg/m2, p = 0.006). The PaO Conclusions: Patients with COVID-19 and bacterial coinfection exhibit worse clinical indicators and increased disease severity, demonstrated by older age, higher BMI, severe hypoxemia, greater need for IMV, and increased mortality. Patients with COVID-19 and coinfection with