Systemic immune response associated with radiation therapy in B-cell non-Hodgkin's lymphoma of Waldeyer's ring

Radiation therapy (RT) is one of the most effective therapeutic modalities for B-cell non-Hodgkin's lymphoma of Waldeyer's ring (WR-B-NHL). However, the responsiveness of RT remains controversial and clinical biomarkers are required to predict survival in RT-treated patients with WR-B-NHL. Previous studies have suggested an association between RT and systemic immune responses. In the present retrospective study, the lymphocyte to monocyte ratio (LMR) was identified as a systemic immune indicator in RT-treated patients with WR-B-NHL, and the prognostic value of the LMR with RT and systemic immune responses were evaluated. The optimal cut-off value of the LMR was selected as 3.14, and a high LMR demonstrated improved prognosis and was considered an independent prognostic indicator in RT-treated patients, particularly in patients with distant non-irradiated lesions. Furthermore, reverse transcription-quantitative polymerase chain reaction and ELISA analysis of irradiated lymphoma cell lines and serum samples from patients with WR-B-NHL demonstrated the upregulated expression levels of 4-1BB ligands, calreticulin and high mobility group box 1 compared with non-irradiated groups. Additionally, CD8(+) T cells and expression levels of interferon- in T cells co-cultured with irradiated cells were significantly increased compared with non-irradiated cells. The results indicated that the anti-programmed cell death protein 1 (PD-1) antibody may serve a role in lymphoma therapy when combined with RT. The results of the present study demonstrated the prognostic significance of the LMR associated with RT in patients with WR-B-NHL and acknowledged the potential use of PD-1 antibody in RT-treated lymphomas.