Differences in Immune Cells Engaged in Cell-Mediated Immunity After Chemotherapy for Far Advanced Pancreatic Cancer

Objectives: Little is known about the effects of chemotherapy on the immunity of cancer patient or the ideal timing for immunotherapy combined with chemotherapy. To address these questions, we evaluated the effect of gemcitabine and cisplatin combination chemotherapy on the immunity of pancreatic cancer patients. Methods: Thirteen patients with far advanced pancreatic cancer were enrolled and 7 sex- and age-matched healthy volunteers were included as a control group. Results: Compared with healthy controls, the amounts of peripheral blood mononuclear cells, dendritic cells (DCs), natural killer cells, CD4+, and CD8+ T cells were reduced. With this numerical suppression, NK cell cytotoxicity to K562 leukemia cells was also significantly impaired (7.7% ± 4.9% versus 21.7% ± 7.9% of DNA loss; P = 0.016). Serum concentrations of VEGF and interleukin-10 (IL-10) were higher than the control group (192.1 ± 114.7 versus 50.8 ± 39.5 pg/mL of vascular endothelial growth factor (VEGF) and 122 ± 68.9 versus 111.4 ± 37.4 pg/mL of IL-10). After 1 cycle of gemcitabine and cisplatin chemotherapy, the impaired immunity of patients with pancreatic cancer was restored. Specifically, the recovery of DCs occurred rapidly and exceeded the value of healthy controls. Levels of the immunosuppressive cytokines, IL-10 and VEGF, gradually decreased during chemotherapy. Conclusions: Systemic chemotherapy seems to be beneficial for restoring the impaired immunity of patients with pancreatic cancer, and one of the ideal times to collect DCs for immunotherapy is after completing each cycle of chemotherapy.