Th2 Dominance Might Induce Carcinogenesis in Patients with HCV-related Liver Cirrhosis

It has been reported that type 2 helper T-cell (Th2) cytokines down-regulate antitumor immunity, while Th1 cytokines up-regulate it. We previously reported that hepatocarcinogenesis was associated with Th2 dominance in patients with hepatitis C virus (HCV)-related liver cirrhosis (LC), but we did not determine whether Th2 dominance induced carcinogenesis or carcinogenesis led to Th2 dominance. The aim of the study was to clarify whether Th2 dominance induces carcinogenesis or vice versa in patients with HCV-related liver diseases.

The study population was 82 adult Japanese patients who had chronic inflammation due to HCV infection diagnosed by pathological examination of liver biopsy specimens, including 21 patients with early hepatocellular carcinoma (eHCC) and HCV-related LC. All patients were admitted to our hospital between 2008 and 2014. eHCC was treated by radiofrequency ablation (RFA). The non-HCC patients were divided into four subgroups based on the fibrosis score of Desment (stage F1-4). Blood samples were collected just before starting RFA and after 4 weeks of RFA. Flow cytometry was used to assess the percentages of IFNγ(+) and IL4(-) (Th1) cells and IFNγ(-) and IL4(+) (Th2) cells in CD4(+) T-cells of peripheral blood before the start of each RFA session.

There were 21 patients with fibrosis stage 1, 21 with stage 2, 18 with stage 3, 22 with stage 4, and 21 patients with eHCC. Before RFA, Th1 cells were significantly more frequent in the F4 and eHCC groups than in the F1 group, although there was no significant difference between the HCC and F1 groups after RFA. Both before and after RFA, Th2 cells were significantly more frequent in the HCC group than in the F1 group.

Th2 dominance was not altered by elimination of eHCC after RFA therapy. Therefore, Th2 dominance might induce carcinogenesis in patients with HCV-related LC rather than carcinogenesis leading to Th2 dominance.