title: IL-31 Serum Protein and Tissue mRNA Levels in Patients with Atopic Dermatitis.
abstract: BACKGROUND
  Severe pruritus is the primary symptom in atopic dermatitis (AD). Recently, the novel cytokine IL-31 has been implicated in the itching associated with AD.
  
  
  OBJECTIVE
  We performed this study to determine whether IL-31 serum levels are elevated in AD patients and to better characterize the relationship between serum IL-31 level and other established laboratory parameters.
  
  
  METHODS
  We recruited 55 AD patients, 34 with allergic type AD and 21 with non-allergic type AD, and 38 healthy, non-atopic controls. We checked the laboratory values, severity score, and serum IL-31 levels in all patients and controls, and IL-31 mRNA levels in lesion skin were measured in 13 subjects with AD and in four controls.
  
  
  RESULTS
  AD patients displayed significantly higher levels of serum IL-31 that were associated with serum IgE, disease severity, and subjective itch intensity. In AD patients, IL-31 mRNA levels from the lesional skin samples also correlated with serum IL-31 level.
  
  
  CONCLUSIONS
  IL-31 is likely one of the many mediators inducing inflammation and pruritus in AD. Although our limited sample size prevents us from making any definitive conclusions, our data demonstrate a strong correlation between IL-31 mRNA level and serum IL-31 protein level, which has never been reported before. Moreover, we found correlations between serum IL-31 level and serum IgE, eosinophil cationic protein, disease severity, and subject itch intensity in certain degrees in AD patients.
authors.affiliation: Department of Dermatology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Song
authors.initials: S
authors.lastname: Kim
authors.forename: Hyun-Je
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hee Seung
authors.initials: HS
authors.lastname: Yang
authors.forename: Eugene
authors.initials: E
authors.lastname: Kim
authors.forename: Ik-Soo
authors.initials: IS
authors.lastname: Huh
authors.forename: Jun-Mo
authors.initials: JM
authors.lastname: Yang