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Normalizing results of 13C-urea breath testing for CO2 production rates in children

P D Klein1, H M Malaty, S J Czinn

  • 1DiaSorin, Inc., Houston, Texas 77030, USA.

Journal of Pediatric Gastroenterology and Nutrition
|September 1, 1999
PubMed

Insights

The 13C-urea breath test for Helicobacter pylori detection can be standardized for children. Calculating urea hydrolysis rate, rather than delta over baseline, provides accurate pediatric results independent of size.

Area of Science:

  • Medical Diagnostics
  • Gastroenterology
  • Pediatric Health

Background:

  • The 13C-urea breath test (13C-UBT) detects Helicobacter pylori infection by measuring 13CO2 enrichment in breath.
  • Breath 13CO2 enrichment is influenced by endogenous CO2 production, which varies with age, sex, weight, and height.
  • The standard 13C-UBT cutoff value (2.4 delta% DOB) established for adults may not be suitable for children due to differing CO2 production.

Purpose of the Study:

  • To establish an accurate cutoff value for the 13C-UBT in pediatric patients.
  • To develop a method for H. pylori detection in children that accounts for anthropometric variations.

Main Methods:

  • Estimates of endogenous CO2 production were integrated with delta over baseline (DOB) values.
  • These combined values were used to compute the host-dependent urea hydrolysis rate.
  • The urea hydrolysis rate was analyzed to determine its suitability as a diagnostic marker in children.

Main Results:

  • The adult cutoff range for urea hydrolysis rate was determined to be 10.4–10.9 microg/min.
  • Individual adult ranges varied by sex (men: 9.6–10.9 microg/min; women: 8.5–12.2 microg/min).
  • In a study of 312 children, a urea hydrolysis rate exceeding 10 microg/min indicated H. pylori infection.

Conclusions:

  • Calculating the urea hydrolysis rate standardizes 13C-UBT results by removing the influence of individual anthropometric differences.
  • A single cutoff value for urea hydrolysis rate is proposed for accurate H. pylori detection in pediatric patients of all ages.
Abstract

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