Analysis of the Isotopic Composition of Exhaled Air by the Diode Laser Spectroscopy Method in the 2-μm Region for Diagnosis of Helicobacter pylori-Associated Diseases

Abstract

To diagnose digestive diseases associated with Helicobacter pylori infection, we applied laser spectroscopic analysis of the 13СО2/12СО2 isotope ratio in the exhaled air, which is based on the use of tunable diode lasers. To analyze the isotopic composition of the exhaled air, we developed a spectrophotometer based on a tunable diode laser. The 13СО2/12СО2 ratio was determined using the spectral range near 2.05 μm, in which the R-branch of the 20013–00001 band of 12СО2 overlaps with the P-branch of the 20012–0001 band of 13СО2. H. pylori infection in the gastrointestinal tract of a group of 309 subjects was diagnosed using the 13C-urea breath test (13C-UBT). The breath test results were compared with the results of morphological analysis of the gastric and duodenal mucosa specimens obtained during fiber gastroduodenoscopy. To compare the results of laser 13C-UBT and histology, we have for the first time proposed to use the total values of the results of the histological analysis of biopsy specimens taken in the body and distal part of the stomach and in the duodenum. The dependence of the results of laser 13C-UBT on the age, nosology, activity and severity of the inflammatory process, and the degree of atrophy and metaplasia, as well as the type of therapy was analyzed. It is shown that the distribution of the results of laser 13C-UBT in patients obtained before and after eradication therapy reflects the epidemiology of gastroduodenal diseases, the incidence of H. pylori infections, the patterns of gastrointestinal tract colonization by H. pylori, the parameters of inflammation, as well as the efficacy of therapy and the characteristics of the recovery of bacterial colonies after unsuccessful therapy.