Autoantibody panel on small extracellular vesicles for the early detection of lung cancer

This study evaluated a different form of autoantibody, which is on small extracellular vesicles (sEVs), as a biomarker for early detection of lung cancer. The sEVs were isolated from plasma by ultracentrifugation and validated with morphology and typical markers. The autoantibody levels were quantified by enzyme-linked immunosorbent assay, and further analysis indicated that the autoantibody panel on sEVs was better than that from serum to distinguish benign lung disease (n = 32) from lung cancer (n = 90). In the prospective study, autoantibody on sEVs performed better in identification of patients with a higher risk of lung cancer. Furthermore, with immunogold labeling transmission electron microscopy, Nanoflow cytometry and binding tests, we illustrated that the autoantibodies could bind to the antigens on sEVs, which may explain the detected autoantibodies on sEVs. Besides, the binding resulted in the attenuation of complement-mediated cytotoxicity, which may contribute to the immune escape of lung cancer.