The clinical importance of PD‑L1 and PD‑1 expression in diffuse large B cell lymphoma

Introduction. The target pathway programmed cell death‑1 (PD‑1)/ programmed death‑ligand 1 (PD‑L1) shows clinical efficacy in solid tumors, but also in Hodgkin’s and non‑Hodgkin’s lymphoma. PD‑L1 expression most often correlates with a poor prognosis and a PD‑1 regulatory factor that mediates immunosuppression. The presence of an increased number of tumor‑infiltrating lymphocytes (TILs) PD‑1 + is a favorable prognostic factor in patients with diffuse large B cell lymphomas (DLBCLs) and follicular lymphomas, while the low number of TILs PD‑1 + is associated with an increased risk of histological transformation. In DLBCLs, TILs PD‑1 + may not reflect the depletion of T‑mediated tumor cells but may be an indicator of lymphoid cell origin. Objectives. The objective of this study was to describe the correlation between PD‑1 and PDL‑1 with survival in patients with the diagnosis of diffuse large B cell lymphoma. Material and methods. We have studied 80 patients and we have analyzed DLBCLs according to the Hans algorithm; in addition, we analyzed PD‑1 and PD‑L1 in tumor cells and in immune cells and we correlated this data with patient’s survival. Results. We found that there is a tendency of decreased survival and therapeutic response in DLBCL patients, with both an intense and weak PD‑L1 positivity in tumor cells. PD‑1 low positivity was associated in higher percentage with relapse and treatment unresponsiveness. Conclusions: Our data suggested that PD‑L1 expression correlates with a poor clinical response although it is not an independent prognostic marker and PD‑1 represents a favorable prediction factor for survival.