Original Article   

Italian Journal of Dermatology and Venereology 2022 Apr 04

DOI: 10.23736/S2784-8671.22.07275-9

Copyright © 2022 EDIZIONI MINERVA MEDICA

language: English

PD-1 and PD-L1 expression in mycosis fungoides and Sézary Syndrome

Alessandro PILERI ^{1, 2} ✉, Valentina TABANELLI ³, Fabio FULIGNI ⁴, Claudio AGOSTINELLI ^{5, 6}, Alba GUGLIELMO ^{1, 2}, Elena SABATTINI ⁵, Vieri GRANDI ⁷, Stefano A. PILERI ³, Nicola PIMPINELLI ⁷

¹ Dermatology Unit, IRCCS Policlinico Sant'Orsola, Bologna, Italy; ² Dermatology Unit, Department of Experimental Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy; ³ Division of Haematopathology, European Institute of Oncology (IEO) IRCCS, Milan, Italy; ⁴ Department of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada; ⁵ Haematopathology Unit, Department of Experimental Diagnostic and Specialty Medicine, S. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy; ⁶ Haematopathology Unit, IRCCS Policlinico Sant'Orsola, Bologna, Italy; ⁷ Department of Health Sciences, Division of Dermatology, University of Florence, Florence, Italy

BACKGROUND: The mechanisms involved in mycosis fungoides and Sezary Syndrome progression are largely unknown. Over the last decade the interest in immune system contrast of neoplasm has grown owing to the introduction of immunotherapy. PD-1 and its ligand (PD-L1) are the target of several immunotherapy treatment. In the literature reports on the expression of PD-1 and PD-L1 have provided contrasting results.
METHODS: In our analysis we investigated PD-1 expression in neoplastic cells and in tumour infiltrating lymphocytes (TILs) as well as PD-L1 expression in tumour cells and in tumour associated macrophages (TAMs). PD-L1 and PD-1 positive cells were counted in 5 high-power fields (HPF) and scored as the average number of positive neoplastic cells/TILs/TAMs per HPF.
RESULTS: From databases of two institutions (Bologna and Florence) thirty-five patients corresponding to 43 biopsies were retrieved. In seven instances sequential biopsies were present. No statistically significant expression was observed comparing early to advanced stages by analysing PD-1 by tumour cells and TILs and of PD-L1 by tumour cells and TAMs.
CONCLUSIONS: Our results corroborate that PD-1 and PD-L1 expression is not stage-dependent in mycosis fungoides and Sezary syndrome. However, PD-1 and PD-L1 expression in affected patients provides a rationale to schedule anti PD-1/PD-L1 drugs.

KEY WORDS: Mycosis fungoides; Sezary Syndrome; Immunotherapy