The upregulation of programmed death 1 on peripheral blood T cells of glioma is correlated with disease progression

Glioma is the most common primary brain tumor. Programmed death 1 (PD-1) is a surface receptor expressed on activated and exhausted T cells, which mediate T cell inhibition upon binding with its ligand. In the current study, we investigated the expression of PD-1 on peripheral CD4+ and CD8+ T cells in glioma patients. Percentage of PD-1+ cells was measured by flow cytometry in 86 glioma cases and 62 healthy controls. Results showed that PD-1 expression was significantly increased in both peripheral CD4+ and CD8+ T cells in glioma ( p