title: IL-4 expression by neutrophils in psoriasis lesional skin upon high-dose UVB exposure.
abstract: BACKGROUND
  Upon a single high dose of UVB irradiation of psoriatic lesional skin, IFN-gamma expression is decreased, whereas IL-4 expression is enhanced. A similar type 1 to type 2 shift was found in dermal T cells derived from irradiated lesional skin as compared to unexposed lesional psoriatic skin. We have found recently that the IL-4 protein detected in situ upon UVB exposure of normal skin was not associated with T cells but with infiltrating neutrophils.
  
  
  OBJECTIVE
  To determine which cell types express IL-4 in psoriatic skin after UVB irradiation.
  
  
  METHODS
  Skin biopsies were obtained from healthy controls and psoriasis patients before and after local UVB exposure. Double immunohistochemical stainings were performed to determine the identity of IL-4-expressing cells.
  
  
  RESULTS
  In the irradiated skin of both healthy controls and patients, IL-4-positive cells coexpressed elastase and CD15, but not CD3.
  
  
  CONCLUSIONS
  IL-4-expressing cells found in psoriatic skin after a single high-dose UVB exposure appeared to be neutrophils.
authors.affiliation: Department of Dermatology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. g.piskin@amc.uva.nl
authors.forename: Gamze
authors.initials: G
authors.lastname: Piskin
authors.forename: Umit
authors.initials: U
authors.lastname: Tursen
authors.forename: Jan D
authors.initials: JD
authors.lastname: Bos
authors.forename: Marcel B M
authors.initials: MB
authors.lastname: Teunissen
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001707:Biopsy, Needle; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000032:analysis* / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D020556:Neutrophil Infiltration / Q000528:radiation effects*; D011565:Psoriasis / Q000473:pathology* / Q000532:radiotherapy*; D011829:Radiation Dosage; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014467:Ultraviolet Therapy / Q000379:methods*
chemical_list: D015415:Biomarkers; D015847:Interleukin-4