title: Diagnosis of Helicobacter pylori infection by means of reduced-dose ¹³C-urea breath test and early sampling of exhaled breath.
abstract: OBJECTIVE
  The aim of this study was to evaluate the accuracy of reduced-dose ¹³C-urea breath test (¹³C-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 ¹³C-UBT was performed after a 4-hour fasting period with 4 points of collection: baseline (T₀), and at 10, 20, and 30 minutes (T₁₀, T₂₀, and T₃₀) after ingestion of 25 mg ¹³C-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 age ± standard 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 T₁₀ (cutoff DOB 2.55‰), S 94.7% (95% confidence interval [CI] 90.9-98.5) and Sp 96.8% (95% CI 93.4-100); at T₂₀ (DOB 2.5‰), S 96.2% (95% CI 92.9-99.5) and Sp 96.1% (95% CI 93.7-99.8); and at T₃₀ (DOB 1.6‰), S 96.2% (95% CI 92.9-99.5) and Sp 94.7% (95% CI 90.8-98.6).
  
  
  CONCLUSIONS
  Low-dose ¹³C-UBT with early sampling is accurate for diagnosing H pylori infection in children and adolescents.
authors.affiliation: *Pediatric Gastroenterology Division, Department of Pediatrics †Department of Pathology, Universidade Federal de São Paulo, Escola Paulista de Medicina (UNIFESP-EPM), São Paulo, Brazil.
authors.forename: Sylmara L M
authors.initials: SL
authors.lastname: Pacheco
authors.forename: Silvio K
authors.initials: SK
authors.lastname: Ogata
authors.forename: Rodrigo S
authors.initials: RS
authors.lastname: Machado
authors.forename: Francy Reis da Silva
authors.initials: FR
authors.lastname: Patrício
authors.forename: Mario L E
authors.initials: ML
authors.lastname: Pardo
authors.forename: Elisabete
authors.initials: E
authors.lastname: Kawakami
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D001944:Breath Tests; D002247:Carbon Isotopes; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000382:microbiology*; D005756:Gastritis / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism / Q000382:microbiology; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D008297:Male; D015995:Prevalence; D012680:Sensitivity and Specificity; D014508:Urea / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D002247:Carbon Isotopes; D014508:Urea