title: Higher serum CCL17 may be a promising predictor of acute exacerbations in chronic hypersensitivity pneumonitis.
abstract: BACKGROUND
  Recent research has suggested that the Th1 and Th2 chemokine/cytokine axis contributes to the development of chronic hypersensitivity pneumonitis (HP). Acute exacerbations (AE) are significant factors in the prognosis of chronic HP. Little is known, however, about these biomarkers in association with AE in chronic HP patients.
  
  
  METHODS
  Fifty-six patients with chronic HP were evaluated, including 14 patients during episodes of AE. Th1 mediators (C-X-C chemokine ligand [CXCL]10 and interferon [IFN]-γ), Th2 mediators (C-C chemokine ligand [CCL]17, interleukin-4, and interleukin-13), and pro-fibrotic mediator (transforming growth factor [TGF]-β) were measured to evaluate the mediators as predictors of AE. C-C chemokine receptor (CCR)4 (receptor for CCL17)-positive lymphocytes were quantified in lung specimens.
  
  
  RESULTS
  Serum CCL17 levels at baseline independently predicted the first episode of AE (HR, 72.0; 95% CI, 5.03-1030.23; p = 0.002). AE was significantly more frequent in the higher-CCL17 group (≥285 pg/ml) than in the lower-CCL17 group (<285 pg/ml) (log-rank test, p = 0.0006; 1-year incidence: higher CCL17 vs. lower CCL17, 14.3% vs. 0.0%). Serum CCL17 levels and CCR4-positive cells during episodes of AE were increased from the baseline (p = 0.01 and 0.031).
  
  
  CONCLUSIONS
  Higher serum concentrations of CCL17 at baseline may be predictive of AE in patients with chronic HP, and CCL17 may contribute to the pathology of AE by inducing the accumulation of CCR4-positive lymphocytes in the lungs.
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Koji
authors.initials: K
authors.lastname: Unoura
authors.forename: Tomoya
authors.initials: T
authors.lastname: Tateishi
authors.forename: Takumi
authors.initials: T
authors.lastname: Akashi
authors.forename: Tamiko
authors.initials: T
authors.lastname: Takemura
authors.forename: Makoto
authors.initials: M
authors.lastname: Tomita
authors.forename: Naohiko
authors.initials: N
authors.lastname: Inase
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yoshizawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000542:Alveolitis, Extrinsic Allergic / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D015415:Biomarkers / Q000097:blood*; D001992:Bronchoalveolar Lavage Fluid; D002452:Cell Count; D054414:Chemokine CCL17 / Q000097:blood*; D002908:Chronic Disease; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D008168:Lung / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D054398:Receptors, CCR4 / Q000096:biosynthesis; D058408:Th1-Th2 Balance
chemical_list: D015415:Biomarkers; C106230:CCL17 protein, human; D054414:Chemokine CCL17; D016207:Cytokines; D054398:Receptors, CCR4