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Analysis of the 13 C‐urea breath test for detection of Helicobacter pylori infection based on the kinetics of Δ‐ 13 CO 2 using laser spectroscopy
Author(s) -
TANAHASHI TOSHIHITO,
KODAMA TADASHI,
YAMAOKA YOSHIO,
SAWAI NAOKI,
TATSUMI YOSHIHIDE,
KASHIMA KEI,
HIGASHI YOJI,
SASAKI YASUHITO
Publication year - 1998
Publication title -
journal of gastroenterology and hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.214
H-Index - 130
eISSN - 1440-1746
pISSN - 0815-9319
DOI - 10.1111/j.1440-1746.1998.tb00722.x
Subject(s) - medicine , breath test , gastroenterology , helicobacter pylori , helicobacter pylori infection , nuclear medicine , urea breath test , receiver operating characteristic
We have previously reported on laser spectroscopy as a simple alternative to mass spectrometry. To validate a simplified 13 C‐urea breath test (UBT) with laser spectroscopy for the detection of Helicobacter pylori in clinical use, we evaluated the optimal time of breath sample collection. The 13 C‐UBT was carried out on each of 102 infected and 70 non‐infected subjects (32 without eradication and 38 after eradication therapy). Breath samples were taken at five time points within 60 min followed by 100 mg of 13 C‐urea administration. The ratio of 13 CO 2 to 12 CO 2 was measured using laser spectroscopy and the recovery of tracer in the exhaled breath was calculated. Results were compared with histological and culture examinations of gastric biopsies to establish the infection status. For statistical evaluation of 13 C‐UBT, the optimal timing of breath sample collection was examined on the basis of the kinetics of Δ‐ 13 CO 2 . In 32 H. pylori ‐negative patients (without therapy), the mean ± 2SD of Δ‐ 13 CO 2 was at its minimum 20 min after urea ingestion whereas in H. pylori ‐positive patients, the mean ± SD Δ‐ 13 CO 2 was maximum at 20 min. In addition, receiver operating characteristic (ROC) curve analysis showed that the cut‐off value was estimated between 2.5–3.0 per mil (‰) at 20 min before therapy. Based on the histology and culture results, the sensitivity, specificity and positive and negative predictive values were 98.0%, 100%, 100% and 94.1%, respectively. In conclusion, 13 C‐UBT with laser spectroscopy is a non‐invasive, simple, sensitive and specific test to determine H. pylori status. Our findings suggest that in clinical use, measurements made at 20 min after substrate administration could be recommended for most sensitive and specific 13 C‐UBT results.