title: T-helper 17 cells: the driving force of psoriasis and psoriatic arthritis.
abstract: OBJECTIVE
  There is growing evidence that two recently recognized, unique subsets of CD4(+)  T-cells, T-helper 17 cells (Th17) and CD4(+)  CD25(+)  regulatory T-cells (Treg), may play important roles in the pathogenesis of psoriasis. This study sought to investigate the relationship between Th17 cells and psoriasis or psoriatic arthritis (PsA).
  
  
  METHODS
  Peripheral blood CD4(+)  T-cells were isolated from 47 patients with psoriasis and 47 controls, and were cultured under various stimulatory conditions. The Th17 cells and regulatory Treg cells were detected by flow cytometry. Plasma interleukin (IL)-17 was measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The proportion of Th17 and Treg cells from peripheral blood mononuclear cells showed no difference between patients with psoriasis and controls. However, psoriasis and PsA patients demonstrated a higher proportion of induced Th17 cells, which was correlated with psoriasis area severity index score. The level of plasma IL-17A in psoriasis was higher than that in controls.
  
  
  CONCLUSIONS
  Th17 cells may play important roles in the pathogenesis of psoriasis and psoriatic arthritis.
authors.affiliation: Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: In Seol
authors.initials: IS
authors.lastname: Yoo
authors.forename: Jeung Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Seung Tak
authors.initials: ST
authors.lastname: Song
authors.forename: Jin Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Hyun Ji
authors.initials: HJ
authors.lastname: Lee
authors.forename: Seong Wook
authors.initials: SW
authors.lastname: Kang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015535:Arthritis, Psoriatic / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D020381:Interleukin-17 / Q000097:blood; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D012720:Severity of Illness Index; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D058504:Th17 Cells / Q000276:immunology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508717:IL17A protein, human; D020381:Interleukin-17