A Study on the Clinical Significance of Blood Exosomal PD-L1 in Non-Small Cell Lung Cancer Patients and its Correlation with PD-L1 in Tumor Tissues.

Exosomal programmed cell-death ligand 1 (ePD-L1) can influence immune inhibition and dysfunction. We were dedicated to unearthing the relation between ePD-L1 in blood and pathological characteristics as well as PD-L1 in tumor tissues. We recruited 65 non-small cell lung cancer (NSCLC) patients for exosome extraction and detected the blood ePD-L1 expression in these patients by enzyme-linked immunosorbent assay (ELISA) method. Besides, the correlation between blood ePD-L1 and patients' pathological characteristics was also analyzed. The expression of PD-L1 in tumor tissues was tested by immunohistochemistry (IHC) and its correlation with blood ePD-L1 expression level was analyzed by Spearman correlation coefficient. No significant correlation was observed in PD-L1 expression levels between blood-derived exosome and tumor tissue. Altogether, high blood ePD-L1 expression was relevant to NSCLC progression, while no such relevance to PD-L1 expression in tumor tissue.