Predictive value of circulating immune cell changes in response to PD-1 blockade and TKI therapy in patients with hepatocellular carcinoma

•Circulating immune cells have shown to have a correlation with the response to immunotherapy in hepatocellular carcinoma patients.•Circulating immune cells have the potential to serve as indicators of the response to immunotherapy, providing a means to monitor dynamic changes and optimize treatment for HCC.•The number of circulating NK cells increased when patients with hepatocellular carcinoma received lenvatinib in combination with ICIs.•A low level of circulating CD3+t and CD4+t cells was associated with a poor prognosis. Purpose: This study investigated the dynamic changes in circulating immune cells following immune checkpoint inhibitors (ICIs), tyrosine kinase inhibitors (TKIs), and interventional therapy in hepatocellular carcinoma (HCC). Methods: HCC patients undergoing transarterial chemoembolization (TACE), TKI, and ICI treatment were included in the treatment group. Peripheral blood samples were collected from these patients before each cycle of PD-1 blockade treatment. Flow cytometry analysis was conducted to assess the composition of peripheral immune cells and identify PD-1-expressing T cells. Results: The treatment group showed a median time-to-tumor progression (TTP) of 8 months and an overall survival (OS) of 19 months. In comparison, the control group had 6 months and 15 months respectively. These differences were statistically significant (P = 0.029 for TTP and P = 0.020 for OS). In HCC patients receiving Lenvatinib, more circulating natural killer (NK) cells were noted. After 1–2 cycles of PD-1 antibody treatment, a general decline in the proportion of circulating PD-1+T cells was found, indicating individual variations in response. Conclusion: Circulating immune cells have the potential to serve as indicators of the response to immunotherapy, providing a means to monitor dynamic changes and optimize treatment for HCC.