title: Paucity of intraepidermal FoxP3-positive T cells in cutaneous T-cell lymphoma in contrast with spongiotic and lichenoid dermatitis.
abstract: BACKGROUND
  FoxP3 is the most specific available marker for regulatory T cells (Tregs). Tumor-associated FoxP3-positive Tregs have been identified in various neoplasms, including cutaneous T-cell lymphoma (CTCL). FoxP3 expression in CTCL varies across groups; few studies have compared CTCL with inflammatory conditions.
  
  
  METHODS
  Lesional skin biopsies from 20 patients with CTCL [13 mycosis fungoides (MF); 7 Sézary syndrome (SS)] and 22 with inflammatory dermatoses (11 spongiotic; 11 lichenoid or interface) were examined for FoxP3 expression by immunohistochemistry. Epidermal FoxP3-positive lymphocytes were counted as a percentage of the total epidermal CD3-positive T-cell population.
  
  
  RESULTS
  FoxP3-positive T cells composed the minority of infiltrate in all major categories. Lower numbers of epidermal FoxP3-positive T cells were observed in CTCL, particularly MF, than in inflammatory dermatoses (P < .001). CTCL neoplastic T cells did not express FoxP3.
  
  
  CONCLUSIONS
  FoxP3-positive T cells are less frequently encountered in MF than in inflammatory dermatoses. FoxP3-positive T cells occur in higher proportions in the dermis than in the epidermis and probably correlate with coexisting inflammatory components. CTCL neoplastic cells do not typically express a Treg phenotype and are associated with low numbers of FoxP3-positive Tregs in the infiltrate. FoxP3 expression by immunohistochemistry may aid histologic evaluation of these conditions.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, MN, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Wada
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Wilcox
authors.forename: Roger H
authors.initials: RH
authors.lastname: Weenig
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Gibson
mesh_terms: D002452:Cell Count; D003872:Dermatitis / Q000378:metabolism* / Q000473:pathology; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017512:Lichenoid Eruptions / Q000378:metabolism* / Q000473:pathology; D009182:Mycosis Fungoides / Q000378:metabolism* / Q000473:pathology; D012751:Sezary Syndrome / Q000378:metabolism* / Q000473:pathology; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors
references.citation: Clin Cancer Res. 2001 Sep;7(9):2682-92
references.pmid: 11555580
references.citation: Blood. 2006 Aug 1;108(3):804-11
references.pmid: 16861339
references.citation: Br J Haematol. 2004 Jul;126(1):81-4
references.pmid: 15198736
references.citation: J Cutan Pathol. 2008 Nov;35(11):1032-9
references.pmid: 18681861
references.citation: Nat Rev Immunol. 2006 Apr;6(4):295-307
references.pmid: 16557261
references.citation: Br J Dermatol. 2008 Jun;158(6):1256-63
references.pmid: 18363755
references.citation: Eur J Haematol. 2008 Jan;80(1):90-1
references.pmid: 18036183
references.citation: J Invest Dermatol. 2006 Oct;126(10):2217-23
references.pmid: 16741512
references.citation: G Ital Dermatol Venereol. 2008 Feb;143(1):15-9
references.pmid: 18833048
references.citation: Cancer Epidemiol Biomarkers Prev. 2007 Oct;16(10):1931-4
references.pmid: 17932340
references.citation: Leuk Lymphoma. 2008 Jun;49(6):1190-201
references.pmid: 18569641
references.citation: J Cutan Pathol. 1997 May;24(5):286-91
references.pmid: 9194581
references.citation: Mod Pathol. 2003 Sep;16(9):857-62
references.pmid: 13679448
references.citation: Leukemia. 2005 Dec;19(12):2247-53
references.pmid: 16193085
references.citation: J Invest Dermatol. 2000 Jun;114(6):1154-7
references.pmid: 10844559
references.citation: Leukemia. 2006 Jun;20(6):1123-9
references.pmid: 16557241
references.citation: Leukemia. 2007 Dec;21(12):2512-8
references.pmid: 17713545
references.citation: Eur J Haematol. 2007 Mar;78(3):260-3
references.pmid: 17253970
references.citation: Eur J Immunol. 2006 Nov;36(11):2832-6
references.pmid: 17051620
references.citation: Blood. 2005 Feb 15;105(4):1640-7
references.pmid: 15514008