title: Differential expression of cytokines in UV-B-exposed skin of patients with polymorphous light eruption: correlation with Langerhans cell migration and immunosuppression.
abstract: BACKGROUND
  Disturbances in UV-induced Langerhans cell migration and T helper (T(H)) 2 cell responses could be early steps in the pathogenesis of PLE.
  
  
  OBJECTIVE
  To establish whether UV-B exposure induces aberrant cytokine expression in the uninvolved skin of patients with polymorphous light eruption (PLE).
  
  
  METHODS
  Immunohistochemical staining and comparison of microscopic sections of skin irradiated with 6 times the minimal dose of UV-B causing erythema and the unirradiated skin of patients with PLE and of healthy individuals.
  
  
  METHODS
  University Medical Center (Dutch National Center for Photodermatoses). Patients Patients with PLE (n = 6) with clinically proven pathological responses to UV-B exposure and normal erythemal sensitivity. Healthy volunteers (n = 5) were recruited among students and hospital staff.
  
  
  METHODS
  Expression of cytokines related to Langerhans cell migration (interleukin [IL] 1, IL-18,and tumor necrosis factor [TNF] alpha); T(H)2 responses (IL-4 and IL-10); and T(H)1 responses (IL-6, IL-12, and interferon gamma). Double staining was performed for elastase (neutrophils), tryptase (mast cells), and CD36 (macrophages).
  
  
  RESULTS
  The number of cells expressing IL-1beta and TNF-alpha was reduced in the UV-B-exposed skin of patients with PLE compared with the skin of healthy individuals (P<.05 for TNF-alpha). No differences were observed in the expression of T(H)1-related cytokines but fewer cells expressing IL-4 infiltrated the epidermis of patients with PLE 24 hours after irradiation (P =.03). After UV exposure TNF-alpha, IL-4, and, to a lesser extent, IL-10 were predominantly expressed by neutrophils.
  
  
  CONCLUSIONS
  The reduced expression of TNF-alpha, IL-4, and IL-10 in the UV-B-irradiated skin of patients with PLE appears largely attributable to a lack of neutrophils, and is indicative of reduced Langerhans cell migration and reduced T(H)2 skewing. An impairment of these mechanisms underlying UV-B-induced immunosuppression may be important in the pathogenesis of PLE.
authors.affiliation: Department of Dermatology, University Medical Center Utrecht, Utrecht. w.kolgen@vumc.nl
authors.forename: Wendy
authors.initials: W
authors.lastname: Kölgen
authors.forename: Marjan
authors.initials: M
authors.lastname: van Meurs
authors.forename: Marjan
authors.initials: M
authors.lastname: Jongsma
authors.forename: Huib
authors.initials: H
authors.lastname: van Weelden
authors.forename: Carla A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.forename: Edward F
authors.initials: EF
authors.lastname: Knol
authors.forename: Willem A
authors.initials: WA
authors.lastname: van Vloten
authors.forename: Jon
authors.initials: J
authors.lastname: Laman
authors.forename: Frank R
authors.initials: FR
authors.lastname: de Gruijl
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016753:Interleukin-10 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010787:Photosensitivity Disorders / Q000276:immunology*; D012867:Skin / Q000276:immunology* / Q000528:radiation effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4