title: Analysis of KL-6 and SP-D as disease markers in bird fancier's lung.
abstract: OBJECTIVE
  KL-6 and SP-D are potential serum markers in interstitial lung diseases. Their discriminative value, and ability to reflect pulmonary disease activity and prognosis in bird fancier's lung were analyzed.
  
  
  METHODS
  We studied 49 patients, 38 unexposed and 9 exposed controls. Serum KL-6 and SP-D concentrations were measured at presentation and a second sample, taken after antigen avoidance, was available in 17 patients. Pulmonary function tests were analyzed at presentation and 2-year follow-up.
  
  
  RESULTS
  KL-6 and SP-D were significantly elevated in patients compared to controls (p < 0.0001). ROC curve analysis revealed that both are equally useful in discriminating patients from controls. Analysis of their value as activity markers showed that both correlated with pulmonary function impairment; however, KL-6 correlated best with diffusing capacity. Evaluation of their predictive value showed that higher levels at onset were associated with improvement of diffusing capacity during follow-up. Further, it was noted that KL-6 and SP-D levels decreased after more than one month of allergen avoidance.
  
  
  CONCLUSIONS
  KL-6 and SP-D appear useful serum markers in bird fancier's lung. Since higher levels are associated with more severe lung function impairment at presentation, and better recovery over time, we postulate that in this disease they are especially markers of disease activity.
authors.affiliation: Heart Lung Center Utrecht, Department of Pulmonology, Sint Antonius Hospital, Nieuwegein, the Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Janssen
authors.forename: Jan C
authors.initials: JC
authors.lastname: Grutters
authors.forename: Hiroe
authors.initials: H
authors.lastname: Sato
authors.forename: Heleen
authors.initials: H
authors.lastname: van Velzen-Blad
authors.forename: Pieter
authors.initials: P
authors.lastname: Zanen
authors.forename: Nobuoki
authors.initials: N
authors.lastname: Kohno
authors.forename: Ken I
authors.initials: KI
authors.lastname: Welsh
authors.forename: Roland M
authors.initials: RM
authors.lastname: du Bois
authors.forename: Jules M M
authors.initials: JM
authors.lastname: van den Bosch
mesh_terms: D000941:Antigens / Q000097:blood*; D000951:Antigens, Neoplasm; D001716:Bird Fancier's Lung / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins; D011237:Predictive Value of Tests; D011379:Prognosis; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood*
chemical_list: D000941:Antigens; D000951:Antigens, Neoplasm; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins; D037663:Pulmonary Surfactant-Associated Protein D