Savarino V, Landi F, Dulbecco P, Ricci C, Tessieri L, Biagini R, Gatta L, Miglioli M, Celle G, Vaira D
Dipartimento di Medicina Interna E Specialità Mediche, Università di Genova, Italy.
Dig Dis Sci. 2000 Nov;45(11):2168-74. doi: 10.1023/a:1026605021484.
This study was carried out to compare the measurements and the diagnostic accuracy of the traditional expensive IRMS and the new economical LARA system using two doses of [13C]urea + two different test meals in patients undergoing upper gastrointestinal endoscopy, both before and after anti-Helicobacter treatment. A total of 354 dyspeptic patients underwent endoscopy with gastric biopsies to diagnose H. pylori infection by CLO-test and histology. No patients had taken antibiotics, bismuth, or antisecretory drugs in the 4 weeks before testing. After overnight fasting, breath samples were collected simultaneously in both plastic and glass tubes at baseline and at 30 and 60 min after urea ingestion. In 237 patients 100 mg [13C]urea + Ensure and in 117 patients 75 mg [13C]urea + citric acid were given. The test was also performed with the two urea dosages and meals in 67 and 64 infected patients, respectively, four weeks after anti-Helicobacter therapy. H. pylori was considered eradicated when both biopsy-based tests were negative. A delta value >5 per thousand was considered positive. Breath samples with insufficient CO2 levels at both 30 and 60 min were excluded from final analysis (N = 37 in pre- and N = 8 in posttreatment). There was excellent agreement between overall delta values of the two machines with both [13C]urea 100 mg + Ensure and [13C]urea 75 mg + citric acid. The 95% CI of the difference against the mean was wider with the former (mean -1.3, +6.3, and -9.4) than with the latter urea dosage and test meal (mean -1.2, +5.2 and -8.1). LARA and IRMS were equally effective (P = NS) in distinguishing infected from uninfected patients before therapy using both doses of [13C]urea and test meals (sensitivity ranged from 95% to 99% and specificity from 95% to 97%). This good performance was maintained in the posttreatment phase (sensitivity ranged from 90% to 100% and specificity from 90% to 97%), without any statistical difference among the various combinations (P = NS). The LARA system is a valid alternative to IRMS in the diagnosis of H. pylori infection. Both machines provide highly reliable results after 30 min, so that the 60 min sample can be avoided. The dose of 75 mg + citric acid suffices to ensure an accurate UBT. The test performed with both devices and [13C]urea dosages is very effective also for posttherapy evaluation of H. pylori status.
本研究旨在比较传统昂贵的同位素比值质谱仪（IRMS）和新型经济的LARA系统的测量结果及诊断准确性，研究对象为接受上消化道内镜检查的患者，在抗幽门螺杆菌治疗前后，使用两种剂量的[13C]尿素加两种不同的测试餐。共有354例消化不良患者接受内镜检查及胃活检，通过CLO试验和组织学诊断幽门螺杆菌感染。在测试前4周内，无患者服用过抗生素、铋剂或抗分泌药物。过夜禁食后，在基线以及摄入尿素后30分钟和60分钟，同时在塑料和玻璃管中采集呼气样本。237例患者给予100mg[13C]尿素加安素，117例患者给予75mg[13C]尿素加柠檬酸。在67例和64例感染患者中，分别在抗幽门螺杆菌治疗4周后，使用两种尿素剂量和测试餐进行测试。当两种基于活检的测试均为阴性时，认为幽门螺杆菌已根除。δ值>5‰被认为是阳性。最终分析排除了在30分钟和60分钟时二氧化碳水平不足的呼气样本（治疗前N = 37例，治疗后N = 8例）。对于100mg[13C]尿素加安素和75mg[13C]尿素加柠檬酸，两台机器的总体δ值之间具有极好的一致性。与后一种尿素剂量和测试餐相比，前一种（平均值-1.3、+6.3和-9.4）相对于平均值的差异的95%置信区间更宽（平均值-1.2、+5.2和-8.1）。在治疗前使用两种剂量的[13C]尿素和测试餐区分感染和未感染患者时，LARA和IRMS同样有效（P = 无统计学意义）（敏感性范围为95%至99%，特异性范围为95%至97%）。在治疗后阶段保持了这种良好表现（敏感性范围为90%至100%，特异性范围为90%至97%），各种组合之间无任何统计学差异（P = 无统计学意义）。LARA系统在诊断幽门螺杆菌感染方面是IRMS的有效替代方案。两台机器在30分钟后均能提供高度可靠的结果，因此可以避免采集60分钟的样本。75mg加柠檬酸的剂量足以确保准确的尿素呼气试验。使用两种设备和[13C]尿素剂量进行的测试对于幽门螺杆菌治疗后状态的评估也非常有效。
