Laser assisted ratio analyser 13C-urea breath testing, for the detection of H. pylori: A prospective diagnostic European multicentre study

Aliment Pharmacol Ther. 1999 Sep;13(9):1171-7. doi: 10.1046/j.1365-2036.1999.00594.x.


Background: Novel technology based on laser optogalvanic spectroscopy called the LARA (Laser Assisted Ratio Analyser) system was developed to measure 12C/13C ratios in breath samples using stable 13C isotopes, to detect Helicobacter pylori infection.

Aim: To determine the sensitivity and specificity of the 13C-LARA-urea breath test in the detection of H. pylori infection in a prospective European multicentre trial; FDA-and EMEA-approved.

Methods: Consecutive dyspeptic patients underwent diagnostic gastroscopy with biopsies for culture and histopathology, to detect H. pylori infection (gold standard). Subsequently, the LARA-urea breath test was performed using either a system without a cold trap (part I) or a system with a cold trap (part II). In both instances baseline, 30-min and 60-min breath samples were collected. The optimum cut-off level for 12C/13C ratios was determined by Receiver Operator Characteristics analysis.

Results: In part I, 544 out of 604 patients were evaluable (low CO2: 47; withdrawn: 13). 284 out of 544 patients (52%) were H. pylori-positive according to the gold standard. The sensitivity of the LARA-urea breath test was 95% and the specificity 94%. In part II, 257 out of 272 were evaluable (low CO2: 14; withdrawn: 1). Sensitivity and specificity were 93% and 96%, respectively.

Conclusion: The LARA-technology represents an accurate and non-invasive testing system for the detection of H. pylori infection. Its major advantages are the use of stable 13C isotope, the high throughput of samples and the easy means of collecting, storing and transporting the samples, thus making the system convenient to both patient and clinician.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Breath Tests / instrumentation
  • Carbon Isotopes
  • Europe
  • Female
  • Gastroscopy
  • Helicobacter Infections / diagnosis*
  • Helicobacter Infections / pathology
  • Helicobacter pylori / isolation & purification*
  • Humans
  • Lasers / standards*
  • Male
  • Middle Aged
  • Prospective Studies
  • Sensitivity and Specificity
  • Urea / metabolism


  • Carbon Isotopes
  • Urea