Prolonged alterations in red blood cell rheology following mild SARS-CoV-2 infection: Implications for microvascular health.

The COVID-19 pandemic has prompted widespread investigation into its systemic effects, focusing on the consequences of even mild SARS-CoV-2 infections. This study explores the impact of mild COVID-19 on red blood cell (RBC) rheology, specifically deformability and aggregation, both critical for efficient microvascular perfusion and oxygen delivery. Using advanced microfluidic techniques, blood samples from 23 individuals recovering from mild COVID-19 were analyzed and compared to 21 healthy controls. Results revealed significant reductions in RBC deformability and increased aggregation tendencies in the post-COVID group, particularly among females. These rheological changes correlated with fibrinogen and D-dimer levels, suggesting links to systemic inflammation and hypercoagulability. Persistent alterations in RBC functionality may underlie the microvascular dysfunction and symptoms of post-acute COVID-19 syndrome (PACS), including fatigue and cognitive impairment. These findings underscore the need for targeted therapeutic approaches and longitudinal studies to address the hematological dimensions of PACS and improve recovery outcomes.