title: Expression of interleukin-17 in lesions of erythema multiforme may indicate a role for T helper 17 cells.
abstract: BACKGROUND
  The aim of this study was to evaluate levels of interleukin (IL)-2, IL-6, IL-8, IL-10, IL-17A and interferon γ (IFN-γ) in the serum of patients with erythema multiforme (EM) and to search for the presence of IL-17-expressing cells in lesional samples of EM.
  
  
  METHODS
  A total of 32 patients (22 females and 10 males) diagnosed with EM of the minor or major type were included in the study. Levels of IL-2, IL-6, IL-8, IL-10, IL-17A and IFN-γ in the serum were determined and compared with healthy controls. Biopsy specimens were stained with haematoxylin and eosin (HE) and monoclonal antibodies to CD4, CD8 and IL-17 for immunohistochemical examination.
  
  
  RESULTS
  IL-2, 6, 8 and 17A were significantly higher in the patient group (p = 0.016, p = 0.001, p = 0.004, p = 0.006, respectively) and levels of IL-10 were significantly lower than in the control group (p = 0.046). The cellular infiltrate in lesions of EM was composed mainly of CD4+ T lymphocytes. The presence of IL-17-expressing cells, at proportion of 5 to 50%, was observed in the infiltrate.
  
  
  CONCLUSIONS
  The demonstration of IL-17-expressing cells in lesions of EM in this study has brought forth the assumption that Th17 cells may be involved in the pathogenesis of EM.
authors.affiliation: Department of Dermatology, Dicle University Faculty of Medicine, Diyarbakir, Turkey.
authors.forename: Zeynep Meltem
authors.initials: ZM
authors.lastname: Akkurt
authors.affiliation: Department of Dermatology, Dicle University Faculty of Medicine, Diyarbakir, Turkey.
authors.forename: Derya
authors.initials: D
authors.lastname: Uçmak
authors.affiliation: Department of Pathology, Dicle University Faculty of Medicine, Diyarbakir, Turkey.
authors.forename: Gül
authors.initials: G
authors.lastname: Türkcü
authors.affiliation: Department of Biochemistry, Dicle University Faculty of Medicine, Diyarbakir, Turkey.
authors.forename: Hatice
authors.initials: H
authors.lastname: Yüksel
authors.affiliation: Diyarbakir Training and Research Hospital, Diyarbakir, Turkey.
authors.forename: Kenan
authors.initials: K
authors.lastname: Yildiz
authors.affiliation: Department of Dermatology, Dicle University Faculty of Medicine, Diyarbakir, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Arıca
keywords: T helper 1; T helper 17; erythema multiforme; interleukin-17