An immunogold single extracellular vesicular RNA and protein (AuSERP) biochip to predict responses to immunotherapy in non‐small cell lung cancer patients

Abstract Conventional PD‐L1 immunohistochemical tissue biopsies only predict 20%–40% of non‐small cell lung cancer (NSCLC) patients that will respond positively to anti‐PD‐1/PD‐L1 immunotherapy. Herein, we present an immunogold biochip to quantify single extracellular vesicular RNA and protein (AuSERP) as a non‐invasive alternative. With only 20 μl of purified serum, PD‐1/PD‐L1 proteins on the surface of extracellular vesicles (EVs) and EV PD‐1/PD‐L1 messenger RNA (mRNA) cargo were detected at a single‐vesicle resolution and exceeded the sensitivities of their bulk‐analysis conventional counterparts, ELISA and qRT‐PCR, by 1000 times. By testing a cohort of 27 non‐responding and 27 responding NSCLC patients, AuSERP indicated that the single‐EV mRNA biomarkers surpass the single‐EV protein biomarkers in predicting patient responses to immunotherapy. Dual single‐EV PD‐1/PD‐L1 mRNA detection differentiated responders from non‐responders with an accuracy of 72.2% and achieved an NSCLC diagnosis accuracy of 93.2%, suggesting the potential for AuSERP to provide enhanced immunotherapy predictions and cancer diagnoses within the clinical setting.