title: Elevated levels of thioredoxin 1 in the lungs and sera of idiopathic pulmonary fibrosis, non-specific interstitial pneumonia and cryptogenic organizing pneumonia.
abstract: OBJECTIVE
  Oxidant stress is thought to be involved in the establishment of idiopathic interstitial pneumonia (IIP). Thioredoxin 1 (TRX1) plays a role as a strong antioxidant in vivo, suggesting that TRX1 may be involved in the pathogenesis of IIPs. However, there is no report on TRX1 levels in the sera of IIPs. In addition, TRX1 expression in the lungs of non-specific interstitial pneumonia (NSIP) and cryptogenic organizing pneumonia (COP) patients also has not been reported. Here, we investigated whether or not TRX1 levels are altered in the lungs and sera of patients with idiopathic pulmonary fibrosis (IPF), NSIP, and COP.
  
  
  METHODS
  Immunohistochemical analysis was performed to examine the expression of TRX1. TRX1 levels in sera were measured using an ELISA kit.
  
  
  RESULTS
  TRX1 was expressed in the bronchiole-alveolar epithelium, especially with regenerative or metaplastic feature, and in alveolar macrophages in usual interstitial pneumonia (UIP) and fibrotic NSIP. TRX1 was weakly expressed in the lungs of cellular NSIP and COP. TRX1 producing cells in UIP (n=16), fibrotic NSIP (n=15), cellular NSIP (n=4), and COP (n=5) were significantly increased when compared to nonsmokers (n=7). TRX1 producing cells in UIP and fibrotic NSIP were significantly increased when compared to cellular NSIP and COP. TRX1 levels in the sera of the patients with IPF (n=32; 74.2 ± 7.5 ng/mL), fibrotic NSIP (n=7; 82.5 ± 18.4 ng/mL), cellular NSIP (n=3; 62.2 ± 3.2 ng/mL) and COP (n=17; 88.8 ± 19.7 ng/mL) were significantly higher than those of control subjects (n=74; 35.3 ± 2.7 ng/mL). Furthermore, TRX1 levels in the sera of IPF patients who later showed acute exacerbation (n=7; 106.6 ± 16.3 ng/mL) were significantly higher than those of IPF patients without acute exacerbation (n=25; 65.1 ± 7.6 ng/mL).
  
  
  CONCLUSIONS
  Overproduction of TRX1 in the lungs and sera may play an important role in the pathogenesis of IIPs.
authors.affiliation: Division of Respirology, Neurology, and Rheumatology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Iwata
authors.forename: Masaki
authors.initials: M
authors.lastname: Okamoto
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Hoshino
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kitasato
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakazaki
authors.forename: Morihiro
authors.initials: M
authors.lastname: Tajiri
authors.forename: Kazuko
authors.initials: K
authors.lastname: Matsunaga
authors.forename: Koichi
authors.initials: K
authors.lastname: Azuma
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Kawayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Haruki
authors.initials: H
authors.lastname: Imaoka
authors.forename: Kiminori
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Seiya
authors.initials: S
authors.lastname: Kato
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Yano
authors.forename: Hisamichi
authors.initials: H
authors.lastname: Aizawa
mesh_terms: D000368:Aged; D018549:Cryptogenic Organizing Pneumonia / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000737:chemistry* / Q000378:metabolism; D017563:Lung Diseases, Interstitial / Q000097:blood / Q000378:metabolism*; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000097:blood / Q000378:metabolism*; D013879:Thioredoxins / Q000032:analysis* / Q000097:blood
chemical_list: D013879:Thioredoxins