[Elevated Fas expression is related to increased apoptosis of circulating CD8(+)T cell in patients with hepatocellular carcinoma]

Objective: To investigate the mechanism of apoptosis of CD8(+)T lymphocyte in peripheral blood of patients with hepatocellular carcinoma (HCC). Methods: The proportion and apoptosis of peripheral blood CD8(+)T lymphocytes in 30 healthy controls, 30 patients with cirrhosis and 60 HCC patients were detected by Flow cytometry, and the expression of Fas on the surface of CD8(+)T lymphocytes was reported. The differences between groups were compared using independent sample t-test, and data of variance were tested with Mann-Whitney U non-parametric test, P < 0.05 was considered statistically significant. Results: The proportion of CD8(+)T lymphocytes in peripheral blood of patients with HCC was 26.4% ± 9.2%, higher than that of 24.5% ± 7.1% in cirrhosis (t = 0.783, P = 0.489), and and healthy control 19.7% ± 4.7% (t = 2.920, P = 0.004). The proportion of apoptotic CD8(+)T lymphocytes in peripheral blood of HCC patients was 25.3% ± 6.5%, of the total CD8(+)T lymphocytes, which was significantly higher than that of healthy controls 12.1%±6.5% (t = 7.555, P < 0.001) and cirrhotic 13.6% ± 5.8% (t = 5.213, P < 0.001), the differences were statistically significant. The proportion of Fas(+)CD8(+)T lymphocytes in the HCC group was 62.2% ± 18.5%, higher than that in the healthy control group 42.6%±16.5% (t = 4.127, P < 0.001) and 46.1% ± 14.5% (t = 2.561, P < 0.01)of the cirrhosis group, the differences were statistically significant. Fas expression was positively correlated with the apoptosis of CD8(+)T lymphocytes (r (2) = 0.113, P < 0.05). Conclusion: The proportion of CD8(+)T lymphocytes in peripheral blood of patients with HCC is higher than that of healthy controls, but the proportion of CD8(+)T lymphocyte apoptosis based on Fas/FasL pathway increased, which may be an important mechanism for tumor cell immune escape.