Comparison of different protocols for 13C-urea breath test for the diagnosis of Helicobacter pylori infection in healthy volunteers.
OBJECTIVE
The (13)C-urea breath test ((13)C-UBT) is the most accurate non-invasive method for diagnosis of Helicobacter pylori infection. However, several methodological issues have not been resolved yet. The aim of this study was to test different protocols of (13)C-UBT to find the optimal test drink and sampling interval.


METHODS
(13)C-UBT was performed at 3-day intervals in 27 healthy volunteers using citric acid (test A), orange juice (B) and still water (C) as test drinks. Breath samples were collected from time 5 to 60 min. A total number of 2106 breath samples were analysed by isotope ratio mass spectrometry (cut-off value 3.5).


RESULTS
Differences in delta values were greater than would be expected by chance (A versus B and A versus C at times 20, 25, 30, 35 and 40 min, p<0.05, Dunnett's method). There were no grey zone- or false-negative results among H. pylori-positive persons in test A at any time, but some were found in tests B and C. Optimal intervals for breath sampling are at times 20 or 25 min after (13)C-urea ingestion.


CONCLUSIONS
Citric acid solution as a test drink and 20- or 25-min breath sampling intervals are optimal for the (13)C-UBT in healthy volunteers.
Kopácová
M
M
Second Department of Internal Medicine, Charles University, Prague, Czech Republic. kopacmar@fnhk.cz
Bures
J
J
Vorísek
V
V
Konstacký
M
M
Rejchrt
S
S
Zivný
P
P
Douda
T
T
Palicka
V
V
D000328:Adult; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D019343:Citric Acid / Q000008:administration & dosage; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000201:enzymology; D006801:Humans; D013058:Mass Spectrometry; D008875:Middle Aged; D012996:Solutions; D014508:Urea; D014510:Urease / Q000378:metabolism
D002247:Carbon Isotopes; D012996:Solutions; D019343:Citric Acid; D014508:Urea; D014510:Urease