title: Bronchoalveolar pH and inflammatory biomarkers in newly diagnosed IPF and GERD patients: a case-control study.
abstract: BACKGROUND
  Several studies have suggested that idiopathic pulmonary fibrosis (IPF) may be related to repeated aspiration of gastric contents over long periods of time. We aimed to investigate differences between pH measured directly in the lung, and biomarkers of acute inflammation in patients with newly diagnosed IPF and in patients with newly diagnosed GERD.
  
  
  METHODS
  All subjects (N=61) underwent collection of medical history, physical examination, pulmonary function testing, bronchoscopy, endoscopy, arterial blood gas analyses, and biochemical testing.
  
  
  RESULTS
  Previously diagnosed GERD was found in 56.7%, typical symptoms of reflux in 80%, and Helicobacter pylori in gastric biopsy specimens in 76.6% of the cases. pH in peripheral branches of bronchi in the cases was 5.32 ± 0.44 and was 6.27 ± 0.31 (p<0.001) in the control group. The average values of LDH, ALP, and CRP in bronchoalveolar aspirate and in serum, as well as TNF-alpha in bronchoalveolar aspirate, were significantly higher in IPF patients.
  
  
  CONCLUSIONS
  The more acidic environment in the bronchoalveolar aspirate of the IPF subjects could contribute to the development or progression of IPF, possibly via changes in local metabolism or by damaging local cells and tissue. However, further studies with larger numbers of patients are required to clarify the role of gastric fluid aspiration in IPF pathogenesis. Our preliminary work has identified inflammatory biomarkers LDH, ALP, and TNF-alpha as potentially important in the pathologic processes in IPF. Further research is needed to determine their importance in clinical intervention and patient care.
authors.affiliation: Department of Pulmonary Diseases and School of Medicine, Split University Hospital, University of Split, Split, Croatia.
authors.forename: Emilija
authors.initials: E
authors.lastname: Lozo Vukovac
authors.affiliation: Department of Cardiology, Split University Hospital, Split, Croatia.
authors.forename: Mislav
authors.initials: M
authors.lastname: Lozo
authors.affiliation: Department of Pulmonary Diseases and School of Medicine, Split University Hospital, University of Split, Split, Croatia.
authors.forename: Kornelija
authors.initials: K
authors.lastname: Mise
authors.affiliation: Department of Pulmonary Diseases and School of Medicine, Split University Hospital, University of Split, Split, Croatia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Gudelj
authors.affiliation: Department of Gastroenterology, Split University Hospital, Split, Croatia.
authors.forename: Željko
authors.initials: Ž
authors.lastname: Puljiz
authors.affiliation: Depatrment of Epidemiology, Teaching Public Health Institute of Split and Dalmatia County and School of Medicine, University of Split, Split, Croatia.
authors.forename: Anamarija
authors.initials: A
authors.lastname: Jurcev-Savicevic
authors.affiliation: Department of Cardiology, Split University Hospital, Split, Croatia.
authors.forename: Anteo
authors.initials: A
authors.lastname: Bradaric
authors.affiliation: Department of Pulmonary Diseases and School of Medicine, Split University Hospital, University of Split, Split, Croatia.
authors.forename: Josipa
authors.initials: J
authors.lastname: Kokeza
authors.affiliation: School of Medicine, University of Zagreb, Zagreb, Croatia.
authors.forename: Josko
authors.initials: J
authors.lastname: Mise
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D001999:Bronchoscopy; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D005764:Gastroesophageal Reflux / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D054990:Idiopathic Pulmonary Fibrosis / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein; D007770:L-Lactate Dehydrogenase; D000469:Alkaline Phosphatase