Tim-3 expression is increased on peripheral T cells from diffuse large B cell lymphoma.

T cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) plays a critical role in immune tolerance by suppressing the activation and proliferation of T cells. The purpose of this study was to investigate the effect of Tim-3 on the development of diffuse large B cell lymphoma (DLBCL). A total of 40 newly diagnosed DLBCL patients and 30 healthy donors were recruited. Tim-3 expression on peripheral CD4+ T and CD8+ T cells was analyzed by flow cytometry. Data showed that expression of Tim-3 was significantly increased on both CD4+ and CD8+ T cells in DLBCL patients than in healthy controls (P < 0.001 and P < 0.001, respectively). Also, level of Tim-3 on CD4+ T cells was positively correlated with CD8+ T cells in patients (P < 0.001). Further analyses revealed that patients with advanced tumor stages had elevated Tim-3 expression on CD4+ and CD8+ T cells compared to those with primary tumor stages. In addition, levels of Tim-3 on CD4+ and CD8+ T cells were significantly elevated in DLBCL patients with bone marrow involvement or B symptoms. Our results suggest that Tim-3 is involved in the development of DLBCL.