Detection of intracellular interleukin‐2 production in peripheral T lymphocytes by flow cytometry in patients with pancreatobiliary malignancies

Background and Aims: To date, it has been reported that cellular immunity is decreased in patients with cancer and investigations into cytokine production has been insufficient. Therefore, we examined intracellular cytokine production by using flow cytometry in patients with cancer and discussed the reasons for the impairment of their immune system. Methods: Eleven patients with hepatobiliary malignancies (68.5 ± 11.8 years of age), eight age-matched controls (70.0 ± 12.0 years of age) and 10 young volunteers (31.9 ± 3.1 years of age) were used in the present study. Stimulated peripheral blood mononuclear cells from these patients were stained with fluorescence-labeled anticytokine monoclonal antibodies and analyzed with a Fluorescence activated cell sorter (FAC)Scan™. Results: The percentage of positively stained T cells was calculated and compared with controls. Repeated measured ANOVA was used for statistical analysis. Interleukin (IL)-2 production was significantly decreased in patients with cancer compared to controls (P = 0.0122), and it may suggest decreased cellular immune activity of the patients. Simultaneously, spontaneous intracellular IL-4 production was observed in patients and age-matched controls, but levels were significantly increased when compared with the young volunteers (P = 0.0052, P = 0.031, respectively). Conclusions: It was of interest that spontaneous intracellular IL-4 production was detected in elderly subjects.