title: Gastroesophageal reflux in bronchiolitis obliterans syndrome: a new perspective.
abstract: BACKGROUND
  Long-term survival after lung transplantation (LTx) is limited largely by bronchiolitis obliterans syndrome (BOS). Gastroesophageal reflux disease (GERD) is proposed as a risk factor for BOS development. This study investigates the relationship between BOS and GERD measured by esophageal impedance.
  
  
  METHODS
  After the initiation of routine screening for GERD, 59 LTx recipients underwent ambulatory esophageal impedance monitoring. Exposure to acid reflux and non-acid liquid reflux was recorded. Clinical outcomes were reviewed to analyze any effect of reflux on the time to development of BOS.
  
  
  RESULTS
  Thirty-seven (65%) had abnormal acid reflux and 16 (27%) had abnormal non-acid reflux. There was no relationship between acid reflux and BOS. The hazard ratio (HR) for development of BOS in the presence of abnormal non-acid reflux was 2.8 (p = 0.043). The HR for development of BOS increased to 3.6 (p = 0.022) when the number of acute rejection episodes was also taken into account.
  
  
  CONCLUSIONS
  GERD is prevalent in LTx recipients and may represent a modifiable risk factor for BOS. This study found non-acid reflux, measured by esophageal impedance to be associated with the development of BOS. Prospective studies are now required to investigate a causal association between GERD and the development of BOS and to establish the role of surgery for GERD in preventing progression to BOS. The methods used to identify GERD in future studies may be important.
authors.affiliation: Department of Transplant Medicine, Harefield Hospital, Harefield, Middlesex, United Kingdom.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: King
authors.forename: Harisubhash
authors.initials: H
authors.lastname: Iyer
authors.forename: Alessandro A
authors.initials: AA
authors.lastname: Leidi
authors.forename: Martin R
authors.initials: MR
authors.lastname: Carby
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001989:Bronchiolitis Obliterans / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D002648:Child; D003371:Cough / Q000453:epidemiology; D004415:Dyspepsia / Q000453:epidemiology; D005500:Follow-Up Studies; D005764:Gastroesophageal Reflux / Q000150:complications*; D006801:Humans; D016040:Lung Transplantation / Q000009:adverse effects*; D008875:Middle Aged; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000601:surgery; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors; D014019:Tissue Donors / Q000706:statistics & numerical data; D055815:Young Adult