title: Gastric juice from patients "on" acid suppressive therapy can still provoke a significant inflammatory reaction by human bronchial epithelial cells.
abstract: BACKGROUND
  Patients with reflux-related respiratory symptoms are frequently treated with proton pump inhibitors (PPI). It is unclear whether aspiration of gastric juice (GJ) from patients "on" PPI can provoke a similar bronchial inflammatory reaction than that observed in patients "off" medication. The goal of this study was to evaluate the effect of GJ from patients with and without PPI treatment on production of IL-8 by human primary bronchial epithelial cells (PBEC).
  
  
  METHODS
  PBEC were exposed during 24 hours to GJ (1/1000) from patients "on" (n=10) and "off" (n=13) PPI and to nonacidic gastric components (pepsin and bile acids). IL-8 concentration in supernatant was measured with enzyme-linked immunosorbent assay. Endotoxin level in GJ samples was analyzed with a LAL assay.
  
  
  RESULTS
  Exposure of PBEC to GJ from patients "on" PPI provoked a higher production of IL-8 than GJ from patients "off" PPI [279 pg/mL (36 to 498) vs. 11 pg/mL (9 to 27)]. A correlation was found between pH of GJ and IL-8 production (r=0.659, P=0.0006). No correlation was found between IL-8 production and concentration of bile acids or pepsin. Filtration (0.20 [mu]m) of GJ from patients "on" PPI reduced IL-8 production. A positive correlation was found between IL-8 production and endotoxin levels of GJ samples (1/1000) (r=0.654, P=0.0007).
  
  
  CONCLUSIONS
  Exposure of bronchial epithelial cells to GJ from patients "on" PPI is able to induce high IL-8 production. These results suggest that aspiration of GJ in patients treated with PPI might still be able to provoke a significant bronchial inflammatory reaction.
authors.affiliation: Center for Gastroenterological Research, University Hospital Gasthuisberg, Belgium.
authors.forename: Veerle
authors.initials: V
authors.lastname: Mertens
authors.forename: Kathleen
authors.initials: K
authors.lastname: Blondeau
authors.forename: Bart
authors.initials: B
authors.lastname: Vanaudenaerde
authors.forename: Robin
authors.initials: R
authors.lastname: Vos
authors.forename: Ricard
authors.initials: R
authors.lastname: Farre
authors.forename: Ans
authors.initials: A
authors.lastname: Pauwels
authors.forename: Geert
authors.initials: G
authors.lastname: Verleden
authors.forename: Dirk
authors.initials: D
authors.lastname: Van Raemdonck
authors.forename: Lieven
authors.initials: L
authors.lastname: Dupont
authors.forename: Daniel
authors.initials: D
authors.lastname: Sifrim
mesh_terms: D000368:Aged; D001647:Bile Acids and Salts / Q000276:immunology; D001980:Bronchi / Q000276:immunology*; D002478:Cells, Cultured; D004731:Endotoxins / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000276:immunology*; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D005750:Gastric Juice / Q000276:immunology* / Q000378:metabolism; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D005764:Gastroesophageal Reflux / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D005773:Gastroscopy; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018836:Inflammation Mediators / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010434:Pepsin A / Q000276:immunology; D054328:Proton Pump Inhibitors / Q000627:therapeutic use*
chemical_list: D001647:Bile Acids and Salts; C508606:CXCL8 protein, human; D004731:Endotoxins; D018836:Inflammation Mediators; D016209:Interleukin-8; D054328:Proton Pump Inhibitors; D010434:Pepsin A