title: Expression of the T-cell regulatory marker FOXP3 in primary cutaneous large B-cell lymphoma tumour cells.
abstract: BACKGROUND
  Primary cutaneous B-cell lymphomas (PCBCL) are subdivided into the aggressive form, primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT) and two subtypes of indolent behaviour (primary cutaneous follicle centre lymphoma and primary cutaneous marginal zone B-cell lymphoma). The difference in clinical behaviour can be explained by the tumour cell itself, or the lymphoma microenvironment including the antitumour immune response.
  
  
  OBJECTIVE
  To investigate the presence of regulatory T cells (Treg), CD4+CD25+FOXP3+, in the microenvironment of PCBCL in correlation with clinical outcome.
  
  
  METHODS
  Tumour specimens of 55 consecutive cases of PCBCL were blinded and analysed for FOXP3, CD4 and CD25 expression by immunohistochemistry. Confocal images were taken with a Leica SP5. Statistical analyses were performed to determine significance. The test was considered significant when P<0.05.
  
  
  RESULTS
  The CD4 and FOXP3 expression as well as the CD4/FOXP3 ratio were significantly increased in PCBCL of indolent behaviour in contrast to PCLBCL, LT (P=0.0002 for CD4, P<0.0001 for FOXP3 and P=0.0345 for FOXP3/CD4 ratio). CD25 expression did not differ in the three groups (P=0.9414). Within the group of patients with PCLBCL, LT we identified a subgroup with FOXP3+ tumour cells as demonstrated by CD20/FOXP3 double stainings. Patients with FOXP3+ PCLBCL, LT tumour cells showed a better prognosis on Kaplan-Meier analysis.
  
  
  CONCLUSIONS
  High numbers of Treg in the lymphoma microenvironment correlate with a better prognosis in PCBCL. In PCLBCL, LT the presence of FOXP3+ tumour cells is beneficial for prognosis suggesting that FOXP3 expression of PCLBCL, LT tumour cells might serve as a tumour suppressor.
authors.affiliation: Working Group of Cutaneous Lymphomas of the Arbeitsgemeinschaft für Dermatologische Forschung (ADF), Germany.
authors.forename: M
authors.initials: M
authors.lastname: Felcht
authors.forename: M
authors.initials: M
authors.lastname: Heck
authors.forename: C
authors.initials: C
authors.lastname: Weiss
authors.forename: J C
authors.initials: JC
authors.lastname: Becker
authors.forename: E
authors.initials: E
authors.lastname: Dippel
authors.forename: C S L
authors.initials: CS
authors.lastname: Müller
authors.forename: D
authors.initials: D
authors.lastname: Nashan
authors.forename: M M
authors.initials: MM
authors.lastname: Sachse
authors.forename: J P
authors.initials: JP
authors.lastname: Nicolay
authors.forename: N
authors.initials: N
authors.lastname: Booken
authors.forename: S
authors.initials: S
authors.lastname: Goerdt
authors.forename: C-D
authors.initials: CD
authors.lastname: Klemke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015704:CD4 Antigens / Q000378:metabolism; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D053208:Kaplan-Meier Estimate; D018442:Lymphoma, B-Cell, Marginal Zone / Q000378:metabolism* / Q000401:mortality; D016403:Lymphoma, Large B-Cell, Diffuse / Q000378:metabolism* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D012878:Skin Neoplasms / Q000378:metabolism* / Q000401:mortality; D059016:Tumor Microenvironment
chemical_list: D014408:Biomarkers, Tumor; D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit