The unique characteristic in peripheral immune cells in patients with advanced hepatocellular carcinoma.

Background/purpose: Recent progress in cancer immunology provides more insight in immune evasion of cancer cells. Cancer cells may achieve immune evasion through several ways including ineffective antigen presentation, T cell checkpoint utilization, immunosuppressive cytokines secretion and immunosuppressive cells recruitment. However, few literatures mentioned about the change of peripheral blood immune cells in advanced hepatocellular carcinoma (HCC) patients. To answer this question, we initiated a pilot study through detailed flow cytometry.

Methods: We enrolled patients with advanced HCC patients who had informed consent to the collection of their peripheral blood. We also recruited healthy individuals for the control group. Using flow cytometry, we analyzed lymphocyte subclasses and the PD-1 or PD-L1 positivity of immune cells in peripheral blood from HCC patients and healthy individuals.

Results: Twenty-four HCC patients were enrolled and twenty healthy individuals were enrolled. Most of the HCC patients were HBV carrier (58.3%), and the mean age was 61 years old. Among 55 immune cell parameters we examined in peripheral blood, 16 were significantly different between advanced HCC patients and healthy individuals by univariate analysis. Multivariate analysis was then conducted by fitting logistic regression model and showed that CD69CD25 Naïve CD4αβT cell percentage and dendritic cell percentage can reasonably predict the advanced HCC status from peripheral blood. By our regression model, the adjusted generalized R2 = 0.918 and the estimated area under the Receiver Operating Characteristic (ROC) curve was 0.99.

Conclusion: CD69CD25 Naïve CD4αβT cell percentage and dendritic cell percentage in peripheral blood are highly correlated with the advanced HCC status. The change may result from immune evasion initiated by hepatocellular carcinoma cells and further investigation is warranted. Validation study is ongoing and this mechanism may be utilized to treat advanced HCC patient in the future.