ABSTRACT
PurposeThe PD-1 (programmed cell death-1) receptor is expressed on the surface of activated T cells. Its ligand, programmed cell death ligand-1 (PD-L1), is expressed on the surface of dendritic cells or macrophages. The PD-1/PD-L1 interaction ensures prevention of autoimmunity by activating the immune system only when needed. In cancers, PD-L1 expressed on the tumour cells binds to PD-1 receptors on the activated T cells, leading to inhibition of the cytotoxic T cells and immunosuppression. PD-1/PD-L1 pathway is upregulated in EBV infection that is known to worsen the CLL prognosis. Therefore, we aimed to study the association between PD-1 and PD-L1 expressions, EBV status and the CLL prognosis.Methods and patientsThe study was conducted on 80 newly diagnosed CLL patients and 80 controls. We analyzed PD-1 and PD-L1 expressions and EBV-DNA load by real-time PCR. The cytogenetic abnormalities and expression of ZAP70 and CD38 were detected by FISH and Flow cytometry, respectively.ResultsPD-1/PD-L1 expressions were significantly upregulated in CLL patients compared to controls. In addition, their mRNA levels were significantly higher in EBV( +) versus EBV( −) patients. High expression of PD-1/PD-L1 was associated with poor prognostic markers (RAI stages of CLL, del 17p13, ZAP70, and CD38 expression), failure of complete remission, shorter progression-free survival, and overall survival.ConclusionHigh expression of PD-1 and PD-L1, together with high EBD-DNA load were linked to worse prognosis in CLL. In addition, PD-1 and PD-L1 might represent suitable therapeutic targets for patients suffering from aggressive CLL. (AU)
Subject(s)
Humans , Male , Female , Middle Aged , B7-H1 Antigen/genetics , Epstein-Barr Virus Infections/immunology , Gene Expression , Leukemia, Lymphocytic, Chronic, B-Cell/virology , Programmed Cell Death 1 Receptor/genetics , ADP-ribosyl Cyclase/analysis , B7-H1 Antigen/metabolism , Case-Control Studies , DNA, Viral/blood , Leukemia, Lymphocytic, Chronic, B-Cell/immunology , Leukemia, Lymphocytic, Chronic, B-Cell/mortality , Prognosis , Programmed Cell Death 1 Receptor/metabolism , Survival AnalysisABSTRACT
PURPOSE: The PD-1 (programmed cell death-1) receptor is expressed on the surface of activated T cells. Its ligand, programmed cell death ligand-1 (PD-L1), is expressed on the surface of dendritic cells or macrophages. The PD-1/PD-L1 interaction ensures prevention of autoimmunity by activating the immune system only when needed. In cancers, PD-L1 expressed on the tumour cells binds to PD-1 receptors on the activated T cells, leading to inhibition of the cytotoxic T cells and immunosuppression. PD-1/PD-L1 pathway is upregulated in EBV infection that is known to worsen the CLL prognosis. Therefore, we aimed to study the association between PD-1 and PD-L1 expressions, EBV status and the CLL prognosis. METHODS AND PATIENTS: The study was conducted on 80 newly diagnosed CLL patients and 80 controls. We analyzed PD-1 and PD-L1 expressions and EBV-DNA load by real-time PCR. The cytogenetic abnormalities and expression of ZAP70 and CD38 were detected by FISH and Flow cytometry, respectively. RESULTS: PD-1/PD-L1 expressions were significantly upregulated in CLL patients compared to controls. In addition, their mRNA levels were significantly higher in EBV( +) versus EBV( -) patients. High expression of PD-1/PD-L1 was associated with poor prognostic markers (RAI stages of CLL, del 17p13, ZAP70, and CD38 expression), failure of complete remission, shorter progression-free survival, and overall survival. CONCLUSION: High expression of PD-1 and PD-L1, together with high EBD-DNA load were linked to worse prognosis in CLL. In addition, PD-1 and PD-L1 might represent suitable therapeutic targets for patients suffering from aggressive CLL.
