To investigate the changes of serum soluble interleukin-2 receptor (sIL-2R) level in hepatocellular carcinoma (HCC) patients undergoing surgery, and to explore its origin and clinical significance.

Clinical data of 45 HCC patients who received surgical treatments from September 2013 to January 2014 in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. Among them, 40 patients were male and 5 female, aged 36-75 years with a median age of 53 years. 6 patients with liver cirrhosis in the same period were selected as controls. The informed consents of all patients were obtained and the local ethical committee approval was received. The serum sIL-2R level was measured by ELISA. According to the median level of serum sIL-2R, all patients were divided into the high- and low-sIL-2R groups. The relationship between preoperative sIL-2R level and clinicopathological parameters, survival prognosis and tumor recurrence was observed. The expression of sIL-2R in liver cancer tissues was analyzed by immunohistochemistry and immunofluorescence staining. The serum sIL-2R level between 2 groups was statistically compared by t test, and the correlation between sIL-2R level and clinicopathological parameters was analyzed by Chi-square test. Survival analysis was conducted by Kaplan-Meier survival analysis and Log-rank test.

The serum sIL-2R level in HCC patients was (142±16) pmol/L, significantly higher than (61±7) pmol/L in patients with liver cirrhosis (t=2.488, P<0.05). The preoperative sIL-2R level was closely related to HBsAg and BCLC staging (χ2=7.753, 4.465; P<0.05). The serum sIL-2R level was significantly decreased within postoperative 1 month, and increased when the tumors recurred, and declined after the resection of recurrent tumors. The median survival of patients in high-sIL-2R group was 25 months, and 33 months in low-sIL-2R group, where significant difference was observed (χ2=3.945, P<0.05). The 3-year recurrence rate in the high-sIL-2R group was 78.2%, significantly higher than 44.6% in low-sIL-2R group (χ2=5.165, P<0.05). Immunohistochemistry and immunofluorescence staining demonstrated that interleukin-2 receptor-α (IL-2Rα) was mainly distributed in the hepatic stellate cells.

The serum sIL-2R level in HCC patients is significantly increased. It is related to tumor recurrence and survival of HCC patients. sIL-2R is derived from hepatic stellate cells, which plays a certain role in the immune regulation of HCC.