A core challenge in administering immune-based treatments for
cancer is the establishment of easily accessible immunological assays that can predict patients' clinical responses to
immunotherapy. In this study, our aim was to predict the
therapeutic effects of adoptive T-cell
therapy in patients with advanced
pancreatic cancer. To do this, we evaluated whole blood
cytokine levels and peripheral regulatory T cells (Tregs) in 46 patients with unresectable or recurrent
pancreatic cancer who received adoptive T-cell
therapy at 2-week intervals. To test immune function, venous blood was obtained from patients before the start of
therapy and 2 weeks after the 4th treatment. Whole blood
interferon (IFN)-α levels (after stimulation with the Sendai virus) were evaluated, as well as the levels of 9
cytokines stimulated with
phytohemagglutinin [
interleukin (IL)-2,
IL-4,
IL-5,
IL-10, IL-12(p70),
IL-13,
tumor necrosis factor-α, IFN-γ, and granulocyte-monocyte
colony-stimulating factor]. Peripheral Tregs were analyzed by flow cytometry. Using the obtained data, we then observed the relationship between these immunological parameters and clinical outcome of patients. We found that the whole blood production of IFN-γ,
IL-2,
IL-4,
IL-5 and
IL-13 significantly increased after adoptive T-cell
therapy, whereas the number of peripheral Tregs did not change. Multivariate Cox proportional hazards analyses indicated that the number of peripheral Tregs before receiving adoptive T-cell
therapy and the change in IFN-γ levels after adoptive T-cell
therapy were independent variables predicting overall survival. The findings of this study indicate that the assay of whole blood IFN-γ production offers promise for evaluating the clinical response of patients to
cancer immunotherapy.