title: Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer.
abstract: BACKGROUND
  In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer.
  
  
  OBJECTIVE
  To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial.
  
  
  METHODS
  Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made.
  
  
  RESULTS
  The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients.
  
  
  CONCLUSIONS
  This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions.
authors.affiliation: Mass Spectrometry Group, Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
authors.forename: J
authors.initials: J
authors.lastname: Sreekumar
authors.affiliation: Mass Spectrometry Group, Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
authors.forename: N
authors.initials: N
authors.lastname: France
authors.affiliation: Mass Spectrometry Group, Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
authors.forename: S
authors.initials: S
authors.lastname: Taylor
authors.affiliation: Mass Spectrometry Group, Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
authors.forename: T
authors.initials: T
authors.lastname: Matthews
authors.affiliation: Mass Spectrometry Group, Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, UK.
authors.forename: P
authors.initials: P
authors.lastname: Turner
authors.affiliation: Royal Albert Edward Infirmary, Wigan, UK.
authors.forename: P
authors.initials: P
authors.lastname: Bliss
authors.affiliation: Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK; Craniofacial Biology Group, School of Dentistry, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: Alan H
authors.initials: AH
authors.lastname: Brook
authors.affiliation: Royal Liverpool University Hospital (RLUH), Liverpool, UK; School of Medicine, University of East Anglia, Norwich, UK.
authors.forename: Ajm
authors.initials: A
authors.lastname: Watson
keywords: Helicobacter pylori; portable quadrupole mass spectrometer; urea breath test