Diagnosis of Helicobacter pylori Infection by Means of Reduced-Dose 13C-Urea Breath Test and Early Sampling of Exhaled Breath

Objective:The aim of this study was to evaluate the accuracy of reduced-dose C-13-urea breath test (C-13-UBT) and early sampling of exhaled breath for the detection of Helicobacter pylori infection in children and adolescents.Methods:Patients up to 20 years old that underwent upper gastrointestinal endoscopy with gastric biopsies were included. The C-13-UBT was performed after a 4-hour fasting period with 4 points of collection: baseline (T-0), and at 10, 20, and 30 minutes (T-10, T-20, and T-30) after ingestion of 25 mg C-13-urea diluted in 100 mL of apple juice. The infection status was defined through 3 invasive methods, and a patient was considered infected with a positive culture or concomitant positive histology and rapid urease test. The absence of infection was defined by all negative histology, rapid urease test, and culture. Analysis of exhaled breath samples was performed with an isotope-selective infrared spectrometer. A receiver-operating characteristic curve analysis was done to define cutoff delta over baseline (DOB) values.Results:A total of 129 patients between the ages of 2.1 and 19 years (median 11.6 years; mean agestandard deviation 11.5 +/- 3.8 years; F:M 85:44) were included. The prevalence of infection was 41.1%. The sensitivity (S) and specificity (Sp) were at T-10 (cutoff DOB 2.55 parts per thousand), S 94.7% (95% confidence interval [CI] 90.9-98.5) and Sp 96.8% (95% CI 93.4-100); at T-20 (DOB 2.5 parts per thousand), S 96.2% (95% CI 92.9-99.5) and Sp 96.1% (95% CI 93.7-99.8); and at T-30 (DOB 1.6 parts per thousand), S 96.2% (95% CI 92.9-99.5) and Sp 94.7% (95% CI 90.8-98.6).Conclusions:Low-dose C-13-UBT with early sampling is accurate for diagnosing H pylori infection in children and adolescents.