Backgrounds: Many studies show an immune imbalance in the tumor environment; some reports show that the T helper 1 (Th1)/ T helper 2 (Th2) ratio, the number of regulatory T-cells (Treg cells) or CD8+T-cells, and the CD8+Tcell/Treg cell ratio are associated with tumor suppression and expansion. Additionally, chemotherapy was reported to affect the immunity of patients with malignancy. Patients and Methods: Using flow cytometry we measured peripheral blood lymphocytes including non T-cells, as well as T-cell subsets such as CD3+T-cells, CD4+T-cells, CD8+T-cells, Treg cells, Th1 cells and Th2 cells before treatment, at the fourth cycle, and at 1, 3, 6 and 12 months after treatment in 21 patients with B-cell lymphoma receiving R-CHOP therapy. We also analyzed the changes in three immune indexes that reflect anti-tumor immunity (the CD4/CD8 ratio, the CD8/Treg ratio and the Th1/Th2 ratio). Results: Compared to pre-treatment there were significant decreases in the CD4/CD8 ratio between 1 month and 12 months after treatment (p<0.001, for all time points). The CD8/Treg ratio gradually increased with treatment with significant increases observed at 6 months (p=0.009) and 12 months after treatment (p=0.002). The Th1/ Th2 ratio showed a significant increase only before 4 cycles of therapy (p=0.007). Conclusion: Based on the changes in these three immune indexes, we propose that anti-tumor immunity improved after R-CHOP therapy, which enhanced the efficacy of R-CHOP therapy for lymphoma as well as its direct cytotoxic activity
032 Bach2 suppresses tumor immunity by repressing effector function-related gene in CD8 + T cells