title: Serum IL-33 levels are increased in patients with psoriasis.
abstract: BACKGROUND
  Interleukin (IL)-33 is a recently identified cytokine, which is a member of the IL-1 family and binds to a heterodimeric receptor comprising ST2 (suppression of tumorigenicity 2) and IL-1 receptor accessory protein. Serum levels of IL-33 have been reported to be upregulated in various T helper (Th)1/Th17-mediated diseases, such as rheumatoid arthritis and inflammatory bowel disease. IL-33 expression is increased in lesional skin in patients with psoriasis, but serum levels in patients with psoriasis have not yet been studied.
  
  
  OBJECTIVE
  To study serum IL-33 levels in patients with psoriasis, a Th1/Th17-mediated skin disease, before and after anti-tumour necrosis factor (TNF)-α therapy.
  
  
  METHODS
  Serum IL-33 levels were measured in patients with psoriasis vulgaris (PV), psoriatic arthritis (PsA) or pustular psoriasis (PP), and compared with those of healthy controls. Associations between serum IL-33 levels and serum TNF-α, IL-6, vascular endothelial growth factor and C-reactive protein levels were also studied. In addition, the effect of IL-33 stimulation on IL-6, IL-8, TNF-α and VEGF secretion by human keratinocyte was analysed.
  
  
  RESULTS
  Serum IL-33 levels in patients with PV, PsA and PP were significantly higher than those in healthy controls. Serum IL-33 levels correlated with serum TNF-α levels in patients with psoriasis, and decreased after anti-TNF-α therapy. IL-33 stimulated IL-6 and IL-8 secretion by human keratinocytes.
  
  
  CONCLUSIONS
  These results suggest that serum IL-33 levels generally reflect increased inflammation in patients with psoriasis.
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Mitsui
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tada
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kamata
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Miyagaki
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sugaya
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kadono
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.affiliation: Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Asano
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D000067596:Interleukin-33 / Q000378:metabolism*; D007378:Interleukins / Q000378:metabolism; D015603:Keratinocytes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000097:blood / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D016207:Cytokines; D000067596:Interleukin-33; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D002097:C-Reactive Protein