title: 'Free' surfactant in gastric aspirates and bronchoalveolar lavage in children with and without reflux oesophagitis.
abstract: OBJECTIVE
  Dipalmitoylphosphatidycholine (DPPC) is the characteristic and main constituent of surfactant. Adsorption of surfactant to epithelial surfaces may be important in the masking of receptors. The aims of the study were to (i) compare the quantity of free DPPC in the airways and gastric aspirates of children with gastroesophageal reflux disease (GORD) to those without and (ii) describe the association between free DPPC levels with airway cellular profile and capsaicin cough sensitivity.
  
  
  METHODS
  Children aged <14 years were defined as 'coughers' if a history of cough in association with their GORD symptoms was elicited before gastric aspirates and nonbronchoscopic bronchoalveolar lavage (BAL) were obtained during elective flexible upper gastrointestinal endoscopy. GORD was defined as histological presence of reflux oesophagitis. Spirometry and capsaicin cough-sensitivity test was carried out in children aged >6 years before the endoscopy.
  
  
  RESULTS
  Median age of the 68 children was 9 years (interquartile range (IQR) 7.2). Median DPPC level in BAL of children with cough (72.7 microg/mL) was similar to noncoughers (88.5). There was also no significant difference in DPPC levels in both BAL and gastric aspirates of children classified according to presence of GORD. There was no correlation between DPPC levels and cellular counts or capsaicin cough-sensitivity outcome measures.
  
  
  CONCLUSIONS
  We conclude that free DPPC levels in the airways and gastric aspirate is not influenced by presence of cough or GORD defined by histological presence of reflux oesophagitis. Whether quantification of adsorbed surfactant differs in these groups remain unknown. Free DPPC is unlikely to have a role in masking of airway receptors.
authors.affiliation: Department of Respiratory Medicine, Royal Children's Hospital, Queensland, Australia. annechang@ausdoctors.net
authors.forename: A B
authors.initials: AB
authors.lastname: Chang
authors.forename: Y C
authors.initials: YC
authors.lastname: Hills
authors.forename: N C
authors.initials: NC
authors.lastname: Cox
authors.forename: G J
authors.initials: GJ
authors.lastname: Cleghorn
authors.forename: P C
authors.initials: PC
authors.lastname: Valery
authors.forename: P J
authors.initials: PJ
authors.lastname: Lewindon
authors.forename: L C
authors.initials: LC
authors.lastname: Ee
authors.forename: G D
authors.initials: GD
authors.lastname: Withers
authors.forename: C
authors.initials: C
authors.lastname: Beem
authors.forename: B A
authors.initials: BA
authors.lastname: Hills
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000032:analysis*; D000293:Adolescent; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology; D002211:Capsaicin; D002648:Child; D002675:Child, Preschool; D003371:Cough / Q000209:etiology / Q000473:pathology*; D004941:Esophagitis / Q000175:diagnosis; D005260:Female; D005750:Gastric Juice / Q000737:chemistry*; D005764:Gastroesophageal Reflux / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D017506:H(+)-K(+)-Exchanging ATPase / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D008297:Male; D011663:Pulmonary Surfactants / Q000032:analysis*
chemical_list: D011663:Pulmonary Surfactants; D015060:1,2-Dipalmitoylphosphatidylcholine; D017506:H(+)-K(+)-Exchanging ATPase; D002211:Capsaicin