title: T-helper 17 cytokines (interleukins 17, 21, 22, and 6, and tumor necrosis factor-α) in patients with alopecia areata: association with clinical type and severity.
abstract: BACKGROUND
  Alopecia areata (AA) is an organ-specific autoimmune disease characterized by T-cell infiltrates and cytokine production. T-helper 17 (Th17) cells are crucially involved in the pathogenesis of autoimmune diseases.
  
  
  OBJECTIVE
  Our aim was to assess the association of Th17 with AA. We examined interleukin (IL)-17, IL-21, IL-22, IL-6, and tumor necrosis factor-alpha (TNF-α) levels in the serum of patients with AA and studied their association with clinical type and severity of AA.
  
  
  METHODS
  The serum concentrations of IL-17, IL-21, IL-22, IL-6, and TNF-α were measured in 47 patients with AA and 40 healthy controls. The clinical type of AA was determined, and the severity of hair loss was assessed in accordance with the Alopecia Areata Investigational Assessment Guideline criteria.
  
  
  RESULTS
  The serum concentrations of IL-17, IL-21, IL-22, IL-6, and TNF-α were significantly higher in patients with AA as compared with healthy controls (mean: IL-17 33.23 ± 11.58 vs. 4.62 ± 1.88 pg/ml; P = 0.000, IL-21 62.10 ± 6.11 vs. 48.38 ± 3.31 pg/ml; P = 0.000, IL-22 19.27 ± 3.36 vs. 7.09 ± 1.62 pg/ml; P = 0.000, IL-6 17.18 ± 3.08 vs. 4.59 ± 1.66 pg/ml; P = 0.000, TNF-α 19.94 ± 3.59 vs. 9.95 ± 2.42 pg/ml; P = 0.000, respectively). There were significant positive correlations between serum IL-17, TNF-α, and disease severity. There was also significant positive correlation between serum IL-22 and duration of AA.
  
  
  CONCLUSIONS
  Our results showed high serum levels of Th17 cytokines among patients with AA that may suggest a functional role of these cytokines in the pathogenesis of this important skin disease. It could also provide the rationale for new treatment strategies in AA.
authors.affiliation: Department of Dermatology and Venereology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
authors.forename: Mona A
authors.initials: MA
authors.lastname: Atwa
authors.affiliation: Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
authors.forename: Nahed
authors.initials: N
authors.lastname: Youssef
authors.affiliation: Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Nervana M
authors.initials: NM
authors.lastname: Bayoumy
mesh_terms: D000293:Adolescent; D000328:Adult; D000506:Alopecia Areata / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007378:Interleukins / Q000097:blood*; D008297:Male; D012720:Severity of Illness Index; D058504:Th17 Cells / Q000276:immunology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D055815:Young Adult; D000097043:Interleukin-22; D000098546:Interleukin-21
chemical_list: D020381:Interleukin-17; D015850:Interleukin-6; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha; D000097043:Interleukin-22; D000098546:Interleukin-21