Characterization of biomarkers in small Extracellular Vesicles during SARS-CoV2 infections in lung transplant patients

Extracellular vesicles (EVs), including small EVs (sEVs), have emerged as crucial biomarkers for various diseases. This study investigated the potential of sEVs as biomarkers for SARS-CoV-2 infection in lung transplant patients, focusing on their role in organ transplants. Plasma samples from five lung transplant recipients diagnosed with SARS-CoV-2 and five healthy controls were analyzed. The sEVs were isolated using an Invitrogen Exosome Isolation Kit, characterized by Nanosight NS300 for particle size (< 200 nm), and quantified for protein concentration using the BCA assay. Extracted protein from the sEVs was subjected to SDS-PAGE, Coomassie staining, and western blotting to detect SARS-CoV-2 spike and nucleocapsid proteins. The results showed that the isolated sEVs from infected lung transplant patients contained significantly higher levels of SARS-CoV-2 spike and nucleocapsid proteins compared to those from the control group. Western blot analysis revealed strong bands corresponding to the spike and nucleocapsid proteins in infected patients, with statistical significance (p < 0.0001 for spike protein and p < 0.05 for nucleocapsid protein). These findings indicate that sEVs may serve as biomarkers for monitoring SARS-CoV-2 infection in lung transplant patients. Further studies with larger sample sizes are needed to validate these results and explore the broader therapeutic applications of sEVs in disease contexts. This study supports the potential utility of sEVs in detecting SARS-CoV-2 infection and monitoring transplant status, warranting additional investigation into their diagnostic value.