PD1/PD-L1 Expressions in Plasmablastic Lymphoma with Clinicopathological Correlation.

Area of Science:

• Immunology
• Oncology
• Pathology

Background:

• The programmed cell death one (PD1)/PD1 ligand (PD-L1) pathway is crucial for immune evasion in cancer.
• Plasmablastic lymphoma (PBL) is an aggressive lymphoma with poorly understood PD1/PD-L1 expression and clinical relevance.
• PBL's association with immune suppression highlights the potential role of the PD1/PD-L1 axis.

Purpose of the Study:

• To investigate the frequency and clinical impact of PD1 and PD-L1 expression in PBL.
• To determine if PD1/PD-L1 axis activation is associated with immune suppression in PBL.
• To identify potential biomarkers for immunotherapy in PBL.

Main Methods:

• Immunohistochemistry was used to assess PD-L1 expression on tumor cells (nPD-L1) and in the tumor microenvironment (sPD-L1).
• PD1 expression on tumor-infiltrating lymphocytes was also evaluated.
• Clinicopathological parameters and overall survival were analyzed in relation to PD-L1 expression.

Main Results:

• A subset of PBL cases showed high PD-L1 expression: 19% by tumor cells (nPD-L1high) and 43% by the tumor microenvironment (sPD-L1high).
• nPD-L1high expression correlated positively with sPD-L1high but not with PD1 expression or other clinicopathological factors.
• Patients with nPD-L1high demonstrated a trend towards shorter overall survival (9.3 vs. 25.5 months).

Conclusions:

• A subset of PBL patients with high tumor cell PD-L1 expression (nPD-L1high) was identified.
• This subset may benefit from PD1/PD-L1 checkpoint blockade therapies.
• Further research on larger cohorts is needed to validate prognostic and predictive biomarkers for the PD1/PD-L1 pathway in PBL.