{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T10:00:29Z","timestamp":1785837629176,"version":"3.56.0"},"reference-count":10,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T00:00:00Z","timestamp":1698019200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Dermatopathology"],"abstract":"<jats:p>Programmed cell death protein 1 (PD-1) plays a pivotal role in immune system regulation, with its expression levels linked to malignancy prognosis. However, existing reports on PD-1 staining in mycosis fungoides (MF) present conflicting findings, and little attention has been given to PD-1 staining in different MF variants. To address this, we conducted a retrospective study, employing immunohistochemistry to examine PD-1 expression in cases of folliculotropic MF and non-folliculotropic MF. We analyzed 24 cases of folliculotropic MF and 18 cases of non-folliculotropic MF, and recorded both the percentage of PD-1-labeled tumor cells and the intensity score (negative, weak, medium, or strong). Our results revealed significant disparity in PD-1 labeling between patch\/plaque MF and folliculotropic MF (p = 0.028). Non-folliculotropic MF exhibited higher PD-1 labeling in tumor cells (58.3%) compared to folliculotropic MF (40.2%). Notably, there was no significant difference in PD-1 staining between folliculotropic MF and non-folliculotropic MF when both were in the early stage\/indolent disease category. However, when considering the tumor stage, folliculotropic MF exhibited PD-1 staining in tumor cells at a rate of 21.1%, while non-folliculotropic MF showed PD-1 staining in tumor cells at a rate of 46.6% (p = 0.005). Additionally, among folliculotropic MF cases, 13 out of 24 cases displayed differing PD-1 expression patterns between epidermal and dermal components, with preserved PD-1 staining in the epidermal component and loss of staining in the dermal component. Furthermore, consistent with the prior literature, tumor cells with large cell transformations exhibited significantly lower PD-1 labeling (p = 0.017). Our findings showcase the unique PD-1 staining patterns in MF.<\/jats:p>","DOI":"10.3390\/dermatopathology10040038","type":"journal-article","created":{"date-parts":[[2023,10,23]],"date-time":"2023-10-23T10:34:20Z","timestamp":1698057260000},"page":"303-309","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Folliculotropic Mycosis Fungoides Is Associated with Decreased PD1 Staining Compared with Classic Mycosis Fungoides"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7058-349X","authenticated-orcid":false,"given":"Haiming","family":"Tang","sequence":"first","affiliation":[{"name":"Department of Pathology, Yale School of Medicine, New Haven, CT 06510, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristin J.","family":"Rybski","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, University of Rochester, Rochester, NY 14642, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Luan","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, Yale School of Medicine, New Haven, CT 06510, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7301-8274","authenticated-orcid":false,"given":"Bruce R.","family":"Smoller","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, University of Rochester, Rochester, NY 14642, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,10,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.anndiagpath.2017.02.003","article-title":"Upregulation of inhibitory signaling receptor programmed death marker-1 (PD-1) in disease evolution from cutaneous lymphoid dyscrasias to mycosis fungoides and Sezary\u2019s syndrome","volume":"28","author":"Nguyen","year":"2017","journal-title":"Ann. Diagn. Pathol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1379","DOI":"10.1001\/archdermatol.2012.2089","article-title":"Differential expression of programmed death-1 (PD-1) in Sezary syndrome and mycosis fungoides","volume":"148","author":"Cetinozman","year":"2012","journal-title":"Arch. Dermatol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1097\/DAD.0b013e3182a72f8c","article-title":"Expression of follicular helper T-cell markers in primary cutaneous T-cell lymphoma","volume":"36","author":"Park","year":"2014","journal-title":"Am. J. Dermatopathol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1097\/DAD.0000000000000258","article-title":"Expression of T-follicular helper markers in sequential biopsies of progressive mycosis fungoides and other primary cutaneous T-cell lymphomas","volume":"37","author":"Bosisio","year":"2015","journal-title":"Am. J. Dermatopathol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1016\/j.pathol.2022.02.008","article-title":"Prevalence of T-cell antigen losses in mycosis fungoides and CD30-positive cutaneous T-cell lymphoproliferations in a series of 153 patients","volume":"54","author":"Wechsler","year":"2022","journal-title":"Pathology"},{"key":"ref_6","first-page":"355","article-title":"PD-1 and PD-L1 expression in mycosis fungoides and Sezary Syndrome","volume":"157","author":"Pileri","year":"2022","journal-title":"Ital. J. Dermatol. Venerol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1097\/DAD.0b013e31821c35cb","article-title":"Expression patterns of the immunosuppressive proteins PD-1\/CD279 and PD-L1\/CD274 at different stages of cutaneous T-cell lymphoma\/mycosis fungoides","volume":"34","author":"Kantekure","year":"2012","journal-title":"Am. J. Dermatopathol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1002\/cyto.b.22070","article-title":"PD-1 improves accurate detection of Sezary cells by flow cytometry in peripheral blood in mycosis fungoides\/Sezary syndrome","volume":"102","author":"Lewis","year":"2022","journal-title":"Cytometry B Clin. Cytom."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1002\/ajh.21960","article-title":"Programmed death 1 is expressed in cutaneous infiltrates of mycosis fungoides and Sezary syndrome","volume":"86","author":"Wada","year":"2011","journal-title":"Am. J. Hematol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1155\/2010\/404069","article-title":"Diagnostic and prognostic utility of PD-1 in B cell lymphomas","volume":"29","author":"Muenst","year":"2010","journal-title":"Dis. Markers"}],"container-title":["Dermatopathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2296-3529\/10\/4\/38\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:10:13Z","timestamp":1760130613000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2296-3529\/10\/4\/38"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,10,23]]},"references-count":10,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2023,12]]}},"alternative-id":["dermatopathology10040038"],"URL":"https:\/\/doi.org\/10.3390\/dermatopathology10040038","relation":{},"ISSN":["2296-3529"],"issn-type":[{"value":"2296-3529","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10,23]]}}}