Objective To research the immune regulation of diammonium glycyrrhizinate （DG） on programmed death-1 （PD-1） expression in monocytes of hepatitis C virus-associated non-Hodgkin lymphomas （HCV-NHL）. Methods The peripheral blood mononuclear cells （PBMCs） were isolated from the peripheral blood of healthy persons

patients with HCV infection and HCV-NHL patients. The PBMCs were cultured in vitro and stimulated. The flow cytometry was used to analyze the ratio of CD14+PD-1+/CD14+ in the healthy persons

patients with HCV infection and HCV-NHL patients. The ratio of CD14+PD-1+/CD14+ was analyzed in HCV-NHL patients after adding DG in the PBMCs and intervention with positive control HCV core antigen as compared with HCV-NHL blank control as well. Results Comparing with the healthy persons

the ratio of CD14+PD-1+/CD14+ in patients with HCV infection and HCV-NHL patients was significantly increased （P<0.05）

especially in HCV-NHL patients （P<0.05）. Comparing with the HCV-NHL blank control

the ratio of CD14+PD-1+/CD14+ in the HCV-NHL+HCV core antigen group was significantly increased （P<0.05）. But the ratio of CD14+PD-1+/CD14+ in the HCV-NHL+DG group was significantly decreased as compared with the HCV-NHL+HCV core antigen group （P<0.05）. Conclusion The activation of PD pathway obviously increases in HCV-NHL patients as compared with patients with HCV infection. DG can decrease the high expression of PD-1+ in HCV-NHL patients.