Chen Tseng-Shing, Chang Full-Young, Chen Pang-Chi, Huang Thomas W, Ou Jonathan T, Tsai Ming-Hung, Wu Ming-Shiang, Lin Jaw-Town
Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, National Yang-Ming University, Taiwan.
J Gastroenterol Hepatol. 2003 Nov;18(11):1237-43. doi: 10.1046/j.1440-1746.2003.03139.x.
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.
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.
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%.
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.
在检测呼气样本中(^{13}CO_2)与(^{12}CO_2)的比例时，红外光谱法与质谱法具有极佳的相关性。本研究旨在使用一种新型红外分析仪评估(^{13}C)尿素呼气试验（(^{13}C - UBT)）的准确性。
共有600例未接受根除治疗且正在接受上消化道内镜检查的患者纳入本研究。对取自胃窦和胃体的活检组织进行培养、组织学检查及快速尿素酶试验，以确定幽门螺杆菌感染情况。在饮用100 mL水中含100 mg (^{13}C)尿素前后分别采集呼气样本。通过受试者工作特征曲线确定最佳截断值。
在586例符合分析条件的患者中，369例幽门螺杆菌感染阳性，185例幽门螺杆菌感染阴性，32例结果不确定。当将合适的截断值设定为千分之3.5时，使用(^{13}C - UBT)获得的灵敏度为97.8%，特异性为96.8%，准确性为97.5%。与呼气样本中(CO_2)浓度≥2%相比，当呼气样本中(CO_2)浓度＜2%时，(^{13}C - UBT)的准确性降低（93.6%对97.7%），主要是因为特异性降低（81.8%对97.7%）。有2.7%的患者(\Delta^{13}CO_2)值在千分之3.0 - 4.5之间，这些患者的误差风险为47%。
采用红外光谱法进行的(^{13}C - UBT)是一种检测幽门螺杆菌感染的高灵敏度、高特异性且非侵入性的方法。检测结果立即可得以及技术简单使其在常规临床实践中特别有效。
