Tanahashi T, Kodama T, Yamaoka Y, Sawai N, Tatsumi Y, Kashima K, Higashi Y, Sasaki Y
Third Department of Internal Medicine, Kyoto Prefectural University of Medicine, Japan.
J Gastroenterol Hepatol. 1998 Jul;13(7):732-7. doi: 10.1111/j.1440-1746.1998.tb00722.x.
We have previously reported on laser spectroscopy as a simple alternative to mass spectrometry. To validate a simplified 13C-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 13C-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 13C-urea administration. The ratio of 13CO2 to 12CO2 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 13C-UBT, the optimal timing of breath sample collection was examined on the basis of the kinetics of delta-13CO2. In 32 H. pylori-negative patients (without therapy), the mean +/- 2SD of delta-13CO2 was at its minimum 20 min after urea ingestion whereas in H. pylori-positive patients, the mean +/- SD delta-13CO2 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 (%0) 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%, and 94.1%, respectively. In conclusion, 13C-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 13C-UBT results.
我们之前曾报道过激光光谱技术可作为质谱分析的一种简单替代方法。为了验证用于临床检测幽门螺杆菌的简化激光光谱13C尿素呼气试验（UBT），我们评估了呼气样本采集的最佳时间。对102名感染患者和70名未感染患者（32名未经根除治疗，38名经过根除治疗）分别进行了13C-UBT。在服用100mg 13C尿素后的60分钟内的五个时间点采集呼气样本。使用激光光谱测量13CO2与12CO2的比率，并计算呼出气体中示踪剂的回收率。将结果与胃活检的组织学和培养检查结果进行比较，以确定感染状况。为了对13C-UBT进行统计学评估，根据δ-13CO2的动力学研究了呼气样本采集的最佳时间。在32名幽门螺杆菌阴性患者（未接受治疗）中，摄入尿素后20分钟时，δ-13CO2的平均值±2SD处于最低水平，而在幽门螺杆菌阳性患者中，δ-13CO2的平均值±SD在20分钟时达到最高。此外，受试者工作特征（ROC）曲线分析表明，治疗前20分钟的临界值估计在2.5-3.0‰（%0）之间。根据组织学和培养结果，敏感性、特异性以及阳性和阴性预测值分别为98.0%、100%和94.1%。总之，激光光谱13C-UBT是一种用于确定幽门螺杆菌感染状况的非侵入性、简单、灵敏且特异的检测方法。我们的研究结果表明，在临床应用中，为获得最灵敏和特异的13C-UBT结果，建议在给予底物后20分钟进行测量。
