Simplified 13C-urea breath test with a new infrared spectrometer for diagnosis of Helicobacter pylori infection.
OBJECTIVE
Infrared spectrometry has correlated excellently with mass spectrometry in detecting the ratio of 13CO(2) to 12CO(2) in breath samples. The present study aimed to evaluate the accuracy of the 13C-urea breath test (13C-UBT) using a new model of infrared analyzer.


METHODS
A total of 600 patients who were undergoing upper endoscopy without receiving eradication therapy were entered into the study. Culture, histology, and rapid urease test on biopsies from the antrum and corpus of the stomach were used for the determination of Helicobacter pylori infection. Breath samples were collected before and 20 min after drinking 100 mg 13C-urea in 100 mL water. The optimal cutoff value was determined by the receiver operating characteristic curve.


RESULTS
Of the 586 patients who were eligible for analysis, 369 were positive for H. pylori infection, 185 were negative for H. pylori infection, and 32 were indeterminate. When the appropriate cutoff value was set at 3.5 per thousand, a sensitivity of 97.8%, a specificity of 96.8% and an accuracy of 97.5% were obtained using the 13C-UBT. The accuracy of the 13C-UBT decreased when CO(2) concentration in the breath sample was <2%, as compared with > or = 2% (93.6%vs 97.7%), mainly because of a decrease in specificity (81.8%vs 97.7%). There were 2.7% of patients with Delta13CO(2) values that fell between 3.0-4.5 per thousand, in whom the risk of error was 47%.


CONCLUSIONS
The 13C-UBT performed with infrared spectrometry is a highly sensitive, specific, and non-invasive method for the detection of H. pylori infection. The immediate availability of the test result and technical simplicity make it particularly effective in routine clinical practice.
Chen
Tseng-Shing
TS
Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, National Yang-Ming University, Taiwan.
Chang
Full-Young
FY
Chen
Pang-Chi
PC
Huang
Thomas W
TW
Ou
Jonathan T
JT
Tsai
Ming-Hung
MH
Wu
Ming-Shiang
MS
Lin
Jaw-Town
JT
D000328:Adult; D000368:Aged; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes; D004724:Endoscopy; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods*; D014508:Urea
D002247:Carbon Isotopes; D014508:Urea