OBJECTIVETo investigate the potential correlation between the level of Th17 cells in peripheral blood and the development of human hepatocellular carcinoma (HCC).

METHODSTh17 cells in the blood samples from 61 HCC patients and 38 healthy controls were assessed by flow cytometry (FCM). The mRNA expression levels of IL-17, IL-23p19 and RORc in peripheral blood mononuclear cells (PBMC) were detected by quantitative real-time PCR. The potential correlation of increased Th17 cells in blood with the clinical characteristics of the 61 patients, including gender, age, preoperative AFP concentration, tumor diameter, portal vein tumor thrombus (PVTT), metastasis and TNM stages was analyzed. Statistical analysis was performed using the software GraphPad Prizm 5.0.

RESULTSThe number of Th17 cells in 61 HCC patients was significantly higher than that in the normal controls (4.67% ± 0.79% vs 3.25% ± 0.68%, P < 0.0001). The same tendency was also found in the mRNA levels of IL-17, IL-23p19 and RORc in PBMC (P < 0.05). The increased level of Th17 cells in HCC patients showed a positive correlation with the tumor size, PVTT, metastasis and TNM stages (P < 0.05 for each group). The level of Th17 cells in HCC patients was increased along with the increasing TNM stages I to stage IV: 4.05% ± 0.82%, 4.32% ± 0.67%, 4.94% ± 0.70%, and 5.22% ± 0.87%, respectively, where the level of Th17 cells in patients with advanced stage of HCC (III-IV) was significantly higher than that in early stage (I-II, P = 0.0008).

CONCLUSIONThe increased of level of Th17 cells in peripheral blood of HCC is significantly correlated with the tumor size, PVTT, metastasis and TNM stage, indicating that the Th17 cells might participate in promoting invasion and progression of HCC directly or indirectly by secreting characteristic cytokines.