title: Induced sputum concentrations of mucin in patients with asthma and chronic cough.
abstract: BACKGROUND
  Mucus hypersecretion is an important pathophysiologic index of airway disease. Measurement of secreted mucin in sputum has been reported in asthma, but not in chronic cough with or without increased sputum production.
  
  
  METHODS
  We studied 49 patients with classic asthma (CA), 39 with cough-variant asthma (CVA), nine and five with chronic cough associated with sinobronchial syndrome (SBS) and gastroesophageal reflux disease (GERD), respectively, and 11 healthy controls. Seventeen patients with CA, but none from the other groups, were taking antiinflammatory medications. Mucin levels in induced sputum supernatants were measured by enzyme-linked immunosorbent assay, which detects airway mucin, probably including MUC5AC and MUC5B.
  
  
  RESULTS
  Mucin levels were higher in patients with CA (674.2 +/- 548.8 microg/mL) and SBS (638.4 +/- 650.7 microg/mL) than in controls (212.0 +/- 167.1 microg/mL) (P = .0037 and .044). They were also higher in patients with CA than in those with CVA (350.4 +/- 374.0 microg/mL) and GERD (134.3 +/- 93.1 microg/mL) (P = .0016 and 0.015), but results did not differ between the latter groups and controls. When the four disease groups were combined, patients with frequent sputum production had greater mucin levels than those with occasional (P = .0023) or no sputum production (P < .0001). Patients with CA showed negative correlations of mucin levels with respiratory resistance indices on impulse oscillation and with airway sensitivity to methacholine.
  
  
  CONCLUSIONS
  Sputum mucin levels differ in various respiratory conditions when compared with controls, primarily reflecting the degree of sputum production. Airway mucin might possibly exert protective effects in asthma, at least between exacerbations, but this issue needs to be further clarified by future studies.
authors.affiliation: Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Shogoin, Sakyoku, Kyoto 606-8507, Japan. niimi@kuhp.kyoto-u.ac.jp
authors.forename: Makiko
authors.initials: M
authors.lastname: Jinnai
authors.forename: Akio
authors.initials: A
authors.lastname: Niimi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ueda
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Matsuoka
authors.forename: Masaya
authors.initials: M
authors.lastname: Takemura
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Kojiro
authors.initials: K
authors.lastname: Otsuka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Oguma
authors.forename: Tomoshi
authors.initials: T
authors.lastname: Takeda
authors.forename: Isao
authors.initials: I
authors.lastname: Ito
authors.forename: Hisako
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Michiaki
authors.initials: M
authors.lastname: Mishima
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001249:Asthma / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D016022:Case-Control Studies; D002908:Chronic Disease; D003371:Cough / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D013183:Sputum / Q000378:metabolism*
chemical_list: D009077:Mucins