Expression of PD-1/PD-L1 in peripheral blood and tumor tissues of patients with classical Hodgkin's lymphoma

Significant biomarkers can predict and estimate the response to chemotherapy for different types of lymphoma. Classical Hodgkin's lymphoma (cHL) and peripheral T-cell lymphoma (PTCL) belong to different types of lymphoma, their prognosis is very different, programmed cell death receptor 1 (PD-1) and its ligand (PD-L1) have been studied in these 2 types of diseases. However, few studies have involved the difference in PD-1/PD-L1 levels between cHL and PTCL. To find out the difference and relevant clinical application value, we collected blood samples of 29 newly diagnosed cHL patients and 11 newly diagnosed PTCL ones. At the same time, tumor tissue paraffin sections of 13 patients with cHL were collected at the initial diagnosis. Flow cytometry, enzyme-linked immunosorbent assay, and immunohistochemical staining were used to detect PD-1/PD-L1 levels in peripheral blood T cells, plasma, and tumor tissues, and the relationship between the above results and clinical data of patients in patients with cHL were investigated. The levels of PD-1 on CD4+ T cells, PD-L1 on CD4+ T cells and PD-1 on CD8+ T cells in peripheral blood of cHL and PTCL patients were higher than those of healthy controls, the level of PD-1 in CD4+ T cells from peripheral blood was higher from cHL patients with stage III-IV (P = .0178), B symptoms (P = .0398), higher lactate dehydrogenase (P = .0056), higher international prognostic index score (P = .0349), and relapsed in later stages (P = .0306). The expression level of soluble PD-L1 (sPD-L1) from cHL (P < .001) and PTCL (P < .0001) patients was higher than that of the healthy control group, and there was higher sPD-L1 level in patients with higher international prognostic index scores (P = .0016). The dynamic detection of sPD-L1 showed that after 2 courses of chemotherapy, the sPD-L1 level in cHL patients with complete remission declined, but the level of sPD-L1 from patients with incomplete remission was not significantly changed (P > .05). In tumor tissues of cHL patients, PD-1(+) was 77%, PD-L1(+) was 69%, PD-1 and PD-L1 expression levels were high. Our results suggest that PD-1 levels in peripheral blood CD4+ T cells are helpful for the stage of disease in patients with cHL, and the dynamic detection of sPD-L1 level is helpful for the judgment of patients with cHL.