Enhanced expression of Programmed cell death 1 (PD-1) protein in benign vascular anomalies

Area of Science:

• Immunology
• Oncology
• Dermatology

Background:

• Programmed cell death 1 (PD-1) and its ligands are key in malignant tumor immune evasion.
• Recent FDA approvals target PD-1/PD-L1 for cancers, but their role in benign tumors is understudied.
• Vascular anomalies, such as infantile haemangiomas and venous malformations, represent benign tumors with limited treatment options.

Purpose of the Study:

• To investigate the expression of PD-1 and PD-L1 in infantile haemangiomas and venous malformations.
• To compare PD-1 and PD-L1 expression in benign vascular anomalies with normal blood vessels.

Main Methods:

• Tissue microarrays (TMAs) were created from infantile haemangioma and venous malformation samples.
• TMAs were stained for PD-1 and PD-L1 antibodies.
• Endothelial cells in normal blood vessels served as controls.

Main Results:

• Endothelial cells in both infantile haemangioma and venous malformation exhibited high PD-1 expression.
• PD-L1 expression was negative in the endothelial cells of these vascular anomalies.
• Normal blood vessel endothelial cells were negative for both PD-1 and PD-L1.

Conclusions:

• Vascular anomalies demonstrate PD-1 over-expression, while PD-L1 is absent.
• The findings suggest a potential therapeutic strategy using immunotherapy targeting PD-1 in benign vascular tumors.
• This opens possibilities for novel treatments when conventional options are exhausted.