PD‐1 expression on the surface of peripheral blood CD4(+) T cell and its association with the prognosis of patients with diffuse large B‐cell lymphoma

The aim of the study was to investigate the relationship between PD‐1 expression on the surface of CD4(+) T cells and prognosis of patients with diffuse large B‐cell lymphoma (DLBCL). Sixty patients who were newly diagnosed with DLBCL and 39 healthy controls were enrolled. In CD4(+) T cells of DLBCL patients, the median MFI of PD‐1 were 541.5 (range: 348.25–758.75), significantly higher than 250 (range: 211–326) in healthy controls (P < 0.001). The ZAP70, PI3K, and NFAT mRNA expression levels of patients were 0.47, 0.47, and 0.62 times, respectively, of those of the healthy controls (P < 0.05). In patients with the percentage of PD‐1 on CD4(+) T cells ≥30.25%, their EFS and OS were significantly lower than patients with PD‐1(+) CD4(+) T cells <30.25% (P < 0.05). The possible explanation is that high PD‐1 expression on CD4(+) cells of DLBCL patients may impair T‐cell function and thus contribute to poor prognosis. There was no relationship between PD‐1 surface expression on CD4(+) T cells and PD‐1 expression within the biopsy of tumor microenvironments from DLBCL patients.