Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Dec;53(6):2909-2912.
doi: 10.1007/s15010-025-02612-x. Epub 2025 Jul 21.

Possible long COVID biomarker: identification of SARS-CoV-2 related protein(s) in Serum Extracellular Vesicles

Asghar Abbasi  1 , Ritin Sharma  2   3 , Nathaniel Hansen  2   3 , Patrick Pirrotte #  2   3 , William W Stringer #  4
Affiliations

Possible long COVID biomarker: identification of SARS-CoV-2 related protein(s) in Serum Extracellular Vesicles

Asghar Abbasi et al. Infection. 2025 Dec.
No abstract available

PubMed Disclaimer

Conflict of interest statement

Declarations. Conflict of interest: Asghar Abbasi is supported by TRDRP (28FT-0017), NIH (R43HL167289, 2R44HL167289-02), and the Johnny Carson Foundation. William Stringer receives research foundation support from the Pulmonary Education and Research Foundation and the UCLA David Geffen School of Medicine (DGSoM)-Ventura County Community Foundation (VCCF) Long COVID 19 Research Award. He reports consulting fees from Verona, Genetech, and Vyaire. He is the co-author of a clinical exercise testing physiology textbook for Lippincott.

Figures

Fig. 1
Fig. 1
Detection of SARS-CoV-2 peptides in serum EVs from individuals with long COVID. A Study design and analytical workflow. Blood samples were collected from individuals with long COVID in response to an acute exercise test (both at rest and peak exercise), before (visit 2) and after (visit 24) completing an exercise training program. Serum EVs were isolated from 56 samples, and proteins were analyzed using mass spectrometry to search for viral peptides. Samples were analyzed by data-independent acquisition mass spectrometry (DIA-MS) with a library-free search against the predicted SARS-CoV-2 proteome. Five EV samples with positive identification of the SARS-CoV-2 polyprotein 1ab (Pp1ab) were further validated using targeted MS2 with a spiked-in stable isotope-labeled synthetic (SIS) peptide standard (“GSLPINVIVFDGK”) (Supplementary Fig. 1). Subsequently, all 56 EV samples were analyzed by targeted MS2 on the Thermo Stellar mass spectrometer for enhanced sensitivity using the same SIS peptide standard. For comparison, 20 control EV samples- collected prior to the COVID-19 pandemic- were processed and analyzed identically using the targeted MS2 workflow with spiked-in SIS peptides. B Heatmap showing EV samples from each long COVID patient with detected SARS-CoV-2 Pp1ab peptides. Color intensity (blue to red) reflects peptide abundance, and the numbers in parentheses indicate how many distinct Pp1ab peptides were found in each sample. The data table is available in Supplementary Table 1. In total, Pp1ab peptides were detected in 22 of the 56 EV samples, with each subject exhibited at least one peptide in their EV cargo. The peptide “GSLPINVIVFDGK,” highlighted in red, was selected for further validation by targeted MS2 analysis. C Overlay of extracted ion chromatograms (EICs) illustrating the SARS-CoV-2 peptide “GSLPINVIVFDGK” detected in EV samples from long COVID patients (endogenous), alongside the matching synthetic reference peptide (spike-in-standard). The matching chromatographic patterns between the endogenous and synthetic peptides confirmed the presence of “GSLPINVIVFDGK” in 12 out of 14 patients with a positive signal. Full chromatogram profiles and related data are provided in Supplementary Table 2. EVs extracellular vesicles, Pt patient, visit 2 pre-training, visit 24 post-training
See this image and copyright information in PMC

References

    1. Menezes SM, Jamoulle M, Carletto MP, Moens L, Meyts I, Maes P, et al. Blood transcriptomic analyses reveal persistent SARS-CoV-2 RNA and candidate biomarkers in post-COVID-19 condition. Lancet Microbe. 2024;5(8): 100849. - DOI - PubMed
    1. Peluso MJ, Swank ZN, Goldberg SA, Lu S, Dalhuisen T, Borberg E, et al. Plasma-based antigen persistence in the post-acute phase of SARS-CoV-2 infection. medRxiv. 2023. 10.1101/2023.10.24.23297114. - DOI - PMC - PubMed
    1. Buzas EI. The roles of extracellular vesicles in the immune system. Nat Rev Immunol. 2022. 10.1038/s41577-022-00763-8. - DOI - PMC - PubMed
    1. Vora A, Zhou W, Londono-Renteria B, Woodson M, Sherman MB, Colpitts TM, et al. Arthropod EVs mediate dengue virus transmission through interaction with a tetraspanin domain containing glycoprotein Tsp29Fb. Proc Natl Acad Sci U S A. 2018;115(28):E6604–13. - DOI - PMC - PubMed
    1. Tang Z, Lu Y, Dong JL, Wu W, Li J. The extracellular vesicles in HIV infection and progression: mechanisms, and theranostic implications. Front Bioeng Biotechnol. 2024;12:1376455. - DOI - PMC - PubMed

LinkOut - more resources