Does the diagnostic accuracy of the 13C-urea breath test vary with age even after the application of urea hydrolysis rate?
BACKGROUND
Endogenous CO(2) production may be a possible explanation for higher false-positive results reported for (13)C-urea breath test (UBT) in children below 6 years. In this study, we evaluated whether age affects the diagnostic accuracy of the (13)C-UBT even after the application of urea hydrolysis rate (UHR) in children.


METHODS
A total of 612 (13)C-UBTs and endoscopic biopsies were performed on children divided into two groups; children under 6 years (n = 126) and children aged 6-18 years (n = 486). For (13)C-UBT, 75 mg (13)C-urea was ingested, and breath sample was collected 30 minutes later. Delta over baseline (DOB) was determined, and UHR was calculated to normalize the DOB values for endogenous CO(2) production.


RESULTS
There was significant difference between the DOB values of children under 6 years and those of children over 6 years in H. pylori-positive (p = .029) and -negative groups (p = .002). On applying the UHR, no significant difference was observed between the UHR values of children under 6 years and those of children over 6 years in H. pylori-positive (p = .877) and -negative groups (p = .427). In 12.6% children under 6 years, false-positive results were observed on applying the DOB, and in 9.0% on applying the UHR (p = .125).


CONCLUSIONS
The (13)C-UBT is a noninvasive method exhibiting high diagnostic accuracy with both UHR as well as DOB. However, high false-positive results for (13)C-UBT were noted in children below 6 years on applying both UHR as well as DOB. Thus, this may not only be due to the effects of endogenous CO(2) production but also due to other factors.
Yang
Hye Ran
HR
Department of Pediatrics, Seoul National University College of Medicine, Seoul, South Korea.
Ko
Jae Sung
JS
Seo
Jeong Kee
JK
D000293:Adolescent; D000367:Age Factors; D001426:Bacterial Proteins / Q000378:metabolism; D001944:Breath Tests / Q000379:methods*; D002138:Calibration; D002247:Carbon Isotopes / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D016099:Endoscopy, Gastrointestinal; D005189:False Positive Reactions; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007223:Infant; D008297:Male; D014508:Urea / Q000032:analysis* / Q000378:metabolism; D014510:Urease / Q000378:metabolism
D001426:Bacterial Proteins; D002247:Carbon Isotopes; D014508:Urea; D014510:Urease