New FTIR methodology for the evaluation of 13C/12C isotope ratio in Helicobacter pylori infection diagnosis

Objectives: The objective of this work was to assess the reliability of a newly developed FTIR (Fourier Transform Infrared spectroscopy) technique for C-13-urea breath test in the non-invasive diagnosis of Helicobacter pylori infection, in comparison to those currently used, isotope ratio mass spectrometry (IRMS) and non-dispersive isotope-selective infrared spectrometry (NDIRS). This new methodology is based on the use of a very less expensive and sophisticated FTIR than IRMS and NDIRS. Materials and Methods: Sixty patients (mate and female, aged between 15-70 years) with dyspeptic symptoms, like the epigastric pain, were tested for H. pylori infection using C-13-urea breath test. Triplicate breath samples were collected before and 30 min after drinking the test solution (75 mg C-13-urea dissolved in 200 ml 0.1 M citric acid). Analysis of delta C-13 were conducted in parallel by means of IRMS, NDIRS and FTIR in order to compare the results. Results: Delta-over-baseline values were over 5 parts per thousand in 18 patients, ranging from 8.81 to 60.88 parts per thousand for IRMS measurements, from 7.2 to 61.2 parts per thousand for NDIRS and from 7.7 to 61.27 parts per thousand for FTIR measurements. The remaining 42 subjects had values well below the 5 parts per thousand cut-off. The results of the base Line-corrected (CO2)-C-13. exhalation values between FTIR and IRMS/NDIRS were in good agreement. Conclusions: The newly developed FTIR methodology has been demonstrated to be a reliable and accurate analytical tool, low cost and easy-to-ope rate, which permits a highly specific measurement of C-13 enrichment in breath samples. As IRMS and NDIRS it allows to adequately discriminate between infected and non-infected subjects. (C) 2009 The British Infection Society. Published by Elsevier Ltd. All rights reserved.