Abstract 610: Dynamic immune landscape of the peripheral blood mononuclear cells from recurrent hepatocellular carcinoma patients undergoing radiofrequency ablation treatment

• Published in: Cancer research (Chicago, Ill.) Vol. 78; no. 13_Supplement; p. 610
• Main Authors: Chen, Dexi, Zhao, Yang, Ouyang, Yabo, Liu, Kai, Rao, Wei, Wei, Feili, Liu, Xiaoni, Shi, Ying, Wang, Shanshan, Pang, Lijun, Qiao, Luxin, Zang, Yunjin, Yin, Xiaoming
• Format: Journal Article
• Language: English
• Published: 01.07.2018
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2018-610

Abstract Hepatocellular carcinoma (HCC) is one of the most common malignancies and the third most lethal malignancy worldwide. Radiofrequency ablation (RFA) is the most commonly used curative treatment for the patients not suitable for surgical resection or liver transplantation. It can cause regional and global anti-tumor immune response, but is insufficient to prevent HCC recurrence in many patients. Peripheral blood mononuclear cells (PBMC) are considered to be the best target for the study of the global immune status after RFA. Previous studies on PBMC were mainly based on traditional flow cytometry, which could not differentiate the complicated immune cell subtypes. In this study, we used mass cytometry to comprehensively characterize the phenotypic and functional alterations of the PBMC in recurrent HCC patients who had received RFA treatment. Fifty-four (54) blood samples from 13 patients were analyzed. Manual gating, SPADE analysis and viSNE analysis were used to interpret the mass cytometry data. The percentage of monocytes showed a fast increase after RFA, and reduced to the normal level before the HCC recurrence (P=0.026). A long-lasting reduction of B cells count were also found after the first RFA (P=0.021), and the B cell count remained at a low level before and after the secondary RFA. The percentage of CD4+ T cells in CD45+ cells was significantly reduced after the first RFA, then restored to the pretreatment level at the time of recurrence, and reduced again after the second RFA(P=0.024). CD8+ T cells showed the same alteration trend as CD4+ cells (P=0.03). We also examined the expression of functional markers in T cells and Tregs. Alterations of CD28 expression were most frequently found in T cells. The Treg population showed a large heterogeneity among the patients with TIM3, LAG3 or CTLA4 positive Tregs being the largest populations. These results suggest a more specific treating modality should be used in combination with the RFA treatment. Citation Format: Dexi Chen, Yang Zhao, Yabo Ouyang, Kai Liu, Wei Rao, Feili Wei, Xiaoni Liu, Ying Shi, Shanshan Wang, Lijun Pang, Luxin Qiao, Yunjin Zang, Xiaoming Yin. Dynamic immune landscape of the peripheral blood mononuclear cells from recurrent hepatocellular carcinoma patients undergoing radiofrequency ablation treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 610.