Landscape and prognostic values of lymphocytes in patients with hepatocellular carcinoma undergoing transarterial embolization.

Transarterial embolization (TACE), the first-line treatment for hepatocellular carcinoma (HCC), does not always lead to promising outcomes in all patients. A better understanding of how the immune lymphocytes changes after TACE might be the key to improve the efficacy of TACE. However, there are few studies evaluating immune lymphocytes in TACE patients. Therefore, we aimed to evaluate the short- and long-term effects of TACE on lymphocyte subsets in patients with HCC to identify those that predict TACE prognosis. Peripheral blood samples were collected from 44 HCC patients at the following time points: one day before the initial TACE, three days after the initial TACE, and one month after the initial TACE and subjected to peripheral blood mononuclear cell isolation and flow cytometry. Dynamic changes in 75 lymphocyte subsets were recorded and their absolute counts were calculated. Tumor assessments were made every 4-6 weeks via computed tomography or magnetic resonance imaging. Our results revealed that almost all lymphocyte subsets fluctuated three days after TACE, but only Tfh and B cells decreased one month after TACE. Univariate and multivariate Cox regression showed that high levels of Th2 and conventional killer Vδ2 cells were associated with longer progressive-free survival (PFS) after TACE. Longer overall survival (OS) after TACE was associated with high levels of Th17 and viral infection-specific Vδ1 cells, and low levels of immature NK cells. In conclusion, TACE has a dynamic influence on the status of lymphocytes. Accordingly, several lymphocyte subsets can be used as prognostic markers for TACE.