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Updated: Jan 27, 2026
Development of a 68Gallium-Labeled D-Peptide PET Tracer for Imaging Programmed Death-Ligand 1 Expression
Published on: February 3, 2023
Expression of programmed cell death ligand 1 and programmed cell death 1 in cutaneous warts
Wesley Y Yu1, Timothy G Berger1, Jeffrey P North2
1Department of Dermatology, University of California, San Francisco, California.
Background:
Cutaneous warts have high prevalence and cause significant morbidity. Understanding the mechanisms by which warts evade the immune system could lead to targeted and improved treatments.
Objective:
To determine whether cutaneous warts express programmed cell death ligand 1 (PD-L1) and to characterize the expression of programmed cell death 1 (PD-1) within the immune infiltrate of inflamed lesions.
Methods:
In total, 44 biopsies of cutaneous warts were retrieved from the Department of Dermatopathology archives of the University of California, San Francisco. Biopsies were stained with hematoxylin and eosin and PD-L1 monoclonal antibody, and biopsies of inflamed lesions were stained with PD-1 monoclonal antibody.
Results:
PD-L1 was expressed on keratinocytes in cases of verrucae vulgares (12/30, 40%) and myrmecia (7/14, 50%) and was associated with an interface inflammatory reaction. PD-1 was expressed by the inflammatory infiltrate in verrucae vulgares (21/24, 88%) and myrmecia (5/8, 63%).
Limitations:
This was a retrospective observational study conducted at a single institution.
Conclusion:
Many cutaneous warts express PD-L1, suggesting that human papillomavirus might use this pathway to promote immune dysfunction. This discovery helps explain the recalcitrance of warts to current therapies and provides a rationale for investigating anti-PD-1 immunotherapy as a potential treatment for warts.
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