title: Circulating thymus and activation-regulated chemokine/CC chemokine ligand 17 is a strong candidate diagnostic marker for interstitial lung disease in patients with malignant tumors: a result from a pilot study.
abstract: BACKGROUND
  Serum Krebs von den Lungen-6 (KL-6) level is an established diagnostic marker of interstitial lung disease (ILD). However, it is also elevated in patients with non-small cell lung cancer (NSCLC). The significance of circulating thymus and activation-regulated chemokine (TARC)/CC chemokine ligand 17 (CCL17) in malignant diseases remains unknown.
  
  
  METHODS
  We measured circulating TARC/CCL17 and KL-6 using enzyme-linked immunosorbent assay and electrochemiluminescence immunoassay, respectively, in 26 patients with malignant disease and six patients with benign lung disease (BLD). The cutoff levels were 500 U/mL for KL-6 and 450 pg/mL for TARC/CCL17. The significance of the markers was evaluated in relationship to the presence of ILD (n=10). The statistical significance was set at P<0.05.
  
  
  RESULTS
  The KL-6 positive ratio was significantly higher in the patients with NSCLC (n=17) than in those with BLD. There was a significant difference in the KL-6 positive ratio between the patients with NSCLC without ILD and those with BLD without ILD. However, there were no significant differences in the TARC/CCL17 positive ratio between the patients with NSCLC and BLD or between those with NSCLC without ILD and those with BLD without ILD. The TARC/CCL17 positive ratio was significantly higher in the patients with malignancy and ILD than in those without ILD. There was also a significant difference in the TARC/CCL17 positive ratio between the patients with NSCLC without ILD and those with ILD.
  
  
  CONCLUSIONS
  TARC/CCL17 may be useful for the diagnosis of ILD in patients with malignancies. Confirmation of the results is warranted through a large-scale study.
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Medical School, Kita-ku, Okayama, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Yamane
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Medical School, Kita-ku, Okayama, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Ochi
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Medical School, Kita-ku, Okayama, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamagishi
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Medical School, Kita-ku, Okayama, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Honda
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Medical School, Kita-ku, Okayama, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Takeyama
authors.affiliation: Department of General Internal Medicine 4, Kawasaki Medical School, Kita-ku, Okayama, Japan.
authors.forename: Nagio
authors.initials: N
authors.lastname: Takigawa
keywords: Krebs von den Lungen-6; biomarker; interstitial lung disease; thymus and activation-regulated chemokine/CC chemokine ligand 17