title: Marked increase in serum KL-6 and surfactant protein D levels during the first 4 weeks after treatment predicts poor prognosis in patients with active interstitial pneumonia associated with polymyositis/dermatomyositis.
abstract: OBJECTIVE
  The aim of this study is to determine whether serum KL-6 and surfactant protein D (SP-D) levels predict the prognosis of patients with interstitial pneumonia (IP) in cases of polymyositis (PM) and dermatomyositis (DM).
  
  
  METHODS
  Fifty consecutive patients with PM (n = 17) or DM (n = 33) and active IP, 6 of whom died of respiratory failure, were enrolled in this study. Serum KL-6 and SP-D levels were measured every 2-4 weeks. Medical records were reviewed retrospectively. Univariate analyses and multivariate analyses with a logistic regression model were conducted.
  
  
  RESULTS
  Serum KL-6 and SP-D levels were elevated in patients with active IP. At the time of diagnosis of active IP, the serum KL-6 level was within the normal range in 28 % of patients and the SP-D level was within the normal range in 46 % of patients. Serum KL-6 level increased up to 3 months after starting treatment and then decreased gradually to baseline, whereas SP-D level peaked within the first 4 weeks after treatment and decreased rapidly to normal levels. Patients with poor prognosis showed increases in KL-6 and SP-D levels during the first 4 weeks after treatment, which was confirmed by uni- and multivariate analyses. Comparing the marker levels at 2-4 weeks after treatment with those at 0 weeks, an increase in the ratio over 1.70 for KL-6 and over 1.75 for SP-D, and an increase in KL-6 over 850 U/ml during the first 4 weeks after treatment, were poor prognostic factors.
  
  
  CONCLUSIONS
  Increases in serum KL-6 and SP-D levels during the first 4 weeks after starting therapy, but not their levels at any one time point, predict poor prognosis in patients with PM/DM. When marked increases of KL-6 and SP-D levels during the first 4 weeks are found or are predicted by serial measurement of the markers, patients have risks of poor prognosis and additional therapy should be considered.
authors.affiliation: Clinical Immunology, Dokkyo Medical University, 880 Kita-Kobayashi, Mibu, Tochigi, 321-0293, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Arai
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kurasawa
authors.forename: Reika
authors.initials: R
authors.lastname: Maezawa
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Owada
authors.forename: Harutsugu
authors.initials: H
authors.lastname: Okada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukuda
mesh_terms: D000328:Adult; D000368:Aged; D003882:Dermatomyositis / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D011379:Prognosis; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: C060192:MUC1 protein, human; D018396:Mucin-1; D037663:Pulmonary Surfactant-Associated Protein D