红外能谱仪检测^13C—尿素呼气试验诊断幽门螺杆菌感染

目的：验证红外能谱仪检测^13C-尿素呼气试验（UBT）诊断幽门螺杆菌（H.pylori)感染的可靠性,并与气体质谱仪检测结果作一比较。方法：对76例患者以红外能谱仪进行^13C－UBT检测H.pylori感染,H.pylor感染状态由快速尿素酶试验、组织学检查以及细菌培养确定。其中17例患者的呼气样本分别用红外能谱仪与气体质谱仪进行检测。结果：76例患者中H.pylori阳性者43例（56．6％）,红外能谱仪进行^13C－UBT的测定结果为41例（53．9％）,其敏感性和特异性分别达到93．0％和97．0％。气体质谱仪与红外能谱仪的检测数值相差无几。结论：以红外能谱仪进行^13C－UBT检测可靠、准确地诊断H.pylori感染,并具有简单、实用的特点。红外能谱仪与气体质谱仪一样可被广泛应用于H.pylori检测。     

13C—尿素呼气试验诊断幽门螺杆菌感染的临床意义

对６５例胃、十二脂肠疾病患者和３６例健康人行１３Ｃ－尿素呼气试验（Ｃ－ＵＢＴ）、病理组织学和快速尿素酶（ＲＵＴ）三种方法检测幽门螺杆菌（ＨＰ），其中任两项阳性者认为有ＨＰ感染。结果显示，Ｃ－ＣＢＴ、病理组织学和ＲＵＴ检测的阳性率分别为８１．５４％、８３．１％、８４．６２％；敏感性分别为９６．２３％、８６．８％、８４．９１％；特异性分别为１００％、９１．６７％、８３．３３％。认为Ｃ－ＵＢＴ和病理组织     

0.75uCi胶囊法^14C—UBT诊断幽门螺杆菌感染

目的评价０７５ｕＣｉ胶囊法１４Ｃ－尿素呼气试验（１４Ｃ－ＵＢＴ）诊断幽门螺杆菌（Ｈｐ）感染的准确性。方法６８１例患者接受１４Ｃ－ＵＢＴ检查。以其中８７例患者胃粘膜活检标本同时快速尿素酶试验和Ｇｉｅｍｓａ染色阳性或同时阴性为标准，评价１４Ｃ－ＵＢＴ２５分钟呼气样本１００ｄｐｍ／ｍｍｏｌＣＯ２为判断阳性阈值的准确性；以无活检资料的５９４例１４Ｃ－ＵＢＴ结果作回顾性分析，检验将１４Ｃ－ＵＢＴ＝１００ｄｐｍ／ｍｍｏｌＣＯ２定为判断Ｈｐ感染界限时，出现误诊的可能性。结果以胃粘膜活检结果为标准，１４Ｃ－ＵＢＴ诊断Ｈｐ感染的准确性为９６６％（８４／８７）；５９４例无活检资料者１４Ｃ－ＵＢＴ值范围为。－１７８０ｄｐｍ／ｍｍｏｌＣＯ２，仅５４％（３２／５９４）落在１００ｐｍ／ｍｍｏｌＣＯ２附近（８０－１２０ｐｍ／ｍｍｏｌＣＯ２），即误诊可能性小于６％。结论０７５ｕＣｉ胶囊法１４Ｃ－ＵＢＴ诊断Ｈｐ感染具有高度的准确性     

~（14）C－尿素呼气试验诊断幽门螺杆菌感染的研究

介绍我们建立的快速、低剂量￣（１４）Ｃ－尿素呼气试验（￣（１４）Ｃ－ＵＢＴ），应用９２．５ｋＢｑ（２．５μＣｉ）￣（１４）Ｃ－尿素，无营养性试餐，在收集５、１０、１５、２０、２５、３０、３５、４５、６０分钟呼气检测的基础上建立了以￣（１４）ＣＯ＿２呼出高峰期（２０分钟），直接以ｄｐｍ／ｍｍｏｌＣＯ＿２表示的检测方法，并以幽门螺杆菌（Ｈｐ）细菌学培养及病理组织学作为参考标准加以对比。对７０例病人的研究结果显示：￣（１４）Ｃ－ＵＢＴ的敏感性为９７．３６％，特异性为９０．００％；诊断符合率为９５．８３％；阳性预测值为９７．３６％，阴性预测值为９０．００％。此外还应用所建立的￣（１４）Ｃ－ＵＢＴ进行了重复性试验及抗Ｈｐ治疗监测试验，资料证明低剂量、快速￣（１４）Ｃ－ＵＢＴ完全可以代替１８５～３７０ｋＢｑ（５～１０μＣｉ）大剂量￣（１４）Ｃ－尿素及长时间的检测方法，其具有简便、快速、准确、安全等优点，可反映体内抗Ｈｐ药物的敏感性，对抗Ｈｐ疗效和Ｈｐ感染复发等方面有很好的监测作用。     

超微剂量14C-尿素呼气试验诊断幽门螺杆菌感染

目的探索１８５ｋＢｑ１４Ｃ尿素呼气试验（ＵＢＴ）诊断幽门螺杆菌（Ｈｐ）的可行性及ＵＢＴ计数与Ｈｐ定量及炎症的关系．方法共１６１例，ＵＢＴ在内镜检查前进行，继１８５ｋＢｑ１４Ｃ尿素溶液吸服２０ｍｉｎ后采集呼出气标本；再吸饮３７ｋＢｑ１４Ｃ尿素溶液，１５ｍｉｎ后再收集标本；测定１４ＣＯ２活性．内镜下取胃窦、胃角及胃体粘膜活检，分别作尿素酶试验、培养、组织Ｇｉｅｍｓａ染色诊断Ｈｐ及病理学检查（ＨＥ染色）判定炎症，任一部位任两项阳性者判为Ｈｐ阳性，３个部位均阳性为（＋＋＋），２个部位阳性为（＋＋），仅１个部位阳性为（＋），炎症分级参照此标准．结果胃粘膜活检Ｈｐ阳性者８３例（５１６％），ＵＢＴ诊断Ｈｐ的敏感性和特异性分别９４０％和９７４％；Ｈｐ（＋＋＋）与Ｈｐ（＋）组间有显著差异（Ｐ＜００５），但炎症程度与活动性与ｍｉｎ－１无明显相关（Ｐ＞００５）．结论１４ＣＵＢＴ是诊断Ｈｐ高度敏感和特异的方法，其计数和Ｈｐ定量之间有良好的相关性，而与胃粘膜炎症无关．     

TSH双位点单抗免疫放射测定法的建立及临床应用

采用本所制备及鉴定的二株不同位点的抗ｈ－ＴＳＨ单抗１３Ｂ４和８Ｅ７，建立了高灵敏度、高特异的ｈ－ＴＳＨ免放测定法。其中经饱和硫酸铵和ＰｒｏｔｅｉｎＡＳｅｐｈａｒｏｓｅ亲和层析柱纯化的１３Ｂ４以Ｉｏｄｏｇｅｎ固相法进行碘标，纯化的８Ｅ７（１∶１００稀释度）作塑料管固相抗体。方法学鉴定表明，本法与生理剂量的其他糖蛋白激素ｈ－ＦＳＨ、ｈ－ＬＨ、ｈＣＧ无明显交叉反应，灵敏度达０．０２６ｍＵ／Ｌ（－ｘ±２ｓ），批内ｃｖ为１．２３～７．３０％，批间ｃｖ为１２．３％。稀释度试验示平行线性关系好，ｒ＝０．９９９。初步临床应用结果表明：甲亢６４例，ＴＳＨ值为未测得（ＮＤ）～０．３１ｍＵ／Ｌ，９５％可信限为ＮＤ～０．２６３ｍＵ／Ｌ；甲减２８例，ＴＳＨ范围为６．６～１８２ｍＵ／Ｌ；甲状腺功能正常者９８例ＴＳＨ为１．４５ｍＵ／Ｌ（Ｐ＿（５０）），９５％可信限为０．３２６～６．０５９ｍＵ／Ｌ。本法与瑞士Ｓｅｒｏｎｏ酶免药盒同时测定１２８例，两种结果的相关系数ｒ＝０．８４４（Ｐ＜０．０１）。经上海华山医院等４家医院初步临床试用，结果表明本法与国内外同类型药盒相比，测定方法简便，相关性高，临床符合率好。     

不稳定性心绞痛患者冠状动脉造影形态学特点及其意义

目的：分析一组不稳定性心绞痛（ＵＡ）患者冠状动脉造影ＩＩ型斑块的发生率、主动脉根部及冠状静脉窦（ＣＳ）血浆凝血烷Ｂ２（血栓素Ｂ２，ＴＸＢ２）及６－酮－前列腺素Ｆ１ａ。（６－酮－ＰＧＦ１ａ）含量的变化。方法：４２例患者（冠心病２９例，非冠心病１３例）纳为受试对象。对冠心病患者［稳定性心绞痛（ＳＡ）９例，ＵＡ２０例］进行了冠状动脉造影病变的形态学分析。对所有受试对象，同时采集升主动脉根部（ＡＯ）及ＣＳ血进行血浆ＴＸＢ２及６－酮－ＰＧＦ１ａ的测定（放射免疫分析法）。结果：ＵＡ患者ＩＩ型斑块的发生率明显高于ＳＡ者（６０％对１１．１％，Ｐ＜０．０５）；ＩＩ型斑块患者血浆ＴＸＢ２ＣＳ／ＡＯ比值明显大于其它斑块者及非冠心病患者（Ｐ＜０．０１，即使在ＵＡ患者中结果亦相似）。结论：ＵＡ患者ＩＩ型斑块的发生率高；ＵＡ患者的发病与斑块局部血小板激活和（或）血栓形成有关。     

套式及免疫套式聚合酶链反应检测乙型肝炎表面抗原阴性肝病患者血清中乙型肝炎病毒DNA

为了更准确、简便而又快速地了解乙型肝炎表面抗原（ＨＢｓＡｇ）阴性肝病患者的病因，建立了套式和免疫套式聚合酶链反应（ＰＣＲ）检测血清中乙型肝炎病毒（ＨＢＶ）ＤＮＡ的技术，结合丙型肝炎病毒（ＨＣＶ）感染指标的检测，对ＨＢｓＡｇ阴性肝病患者的病因进行了研究。发现套式ＰＣＲ能将单次ＰＣＲ的敏感性稳定地提高１０００倍；免疫套式ＰＣＲ可检测到０．１～０．０１ｐｇ／Ｌ水平。检测ＨＢｓＡｇ阴性肝硬化２２例（Ａ组）、ＨＢｓＡｇ阴性慢性肝炎１３例（Ｂ组）、ＨＢｓＡｇ阴性和乙型肝炎病毒核心抗体（抗－ＨＢｃ）阳性正常对照组３０例（Ｃ组）及ＨＢｓＡｇ（＋）／ＨＢｅＡｇ（－）肝硬化患者１２例（Ｄ组），分别有４５．５％、３０．８％、１３．３％和１００％患者血清中ＨＢＶＤＮＡ阳性。ＨＢＶＤＮＡ在一些抗－ＨＢｓ（＋）肝病患者和所谓健康人的血清中也存在。Ａ、Ｂ两组检出有ＨＢＶ和（或）ＨＣＶ感染患者分别占８１．８％和５３．８％。提示套式和免疫套式ＰＣＲ是简便、快速而又高度敏感的检测方法；ＨＢＶ感染可能是引起ＨＢｓＡｇ阴性慢性肝病的重要原因，且ＨＢｓＡｇ阴性肝病病因大多与病毒感染有关；应该重新认识自然感染者血清中抗－ＨＢｓ的临床意义。     

13C-尿素呼气试验对幽门螺杆菌密度及胃黏膜炎症的判断价值

目的 探讨６１３Ｃ尿素呼气试验（ＵＢＴ）对幽门螺杆菌（Ｈｐ）感染密度及胃黏膜炎症程度的判断价值。方法 以病理组织学为对照,分析ＵＢＴ对Ｈｐ诊断的准确性并比较不同细菌感染密度以及不同炎症细胞浸润程度时ＵＢＴ结果（ＤＯＢ值）的差异。结果 ＵＢＴ对Ｈｐ诊断的敏感性为９３．２％,特异性为８９．１％。Ｈｐ感染密度重度组的ＤＯＢ值显著高于轻中度组（Ｐ〈０．０５）,ＷＳ染色分级与ＤＯＢ值之间具有弱相关性（ｒｓ＝     

国产试剂进行微剂量^14C—尿素呼气试验效果评价

目的 评价应用新型国产试剂进行微剂量（３７ＫＰｑ＾）＾１４Ｃ－尿素呼气试验（１４Ｃ－ＵＢＴ）对幽门螺杆菌（ＨＰ）感染的诊断价值。方法 ５９例ＨＰ阳性病人和４７例ＨＰ阴性对照接受试验。试验所用试剂全曾国产化，包括＾１４Ｃ－尿素、ＣＯ２吸收剂、闪烁剂。ＲＯＣ分析法确定＾１４Ｃ－ＵＢＴ最适差别值。１９例志愿者第二日重复试验。结果 ＲＯＣ分析法得出＾１４Ｃ－ＵＢＴ最适差别值为２５０ｄｐｍ／ｍ ｍｏｌ ＣＯ     

Simplified 13C-urea breath test with a new infrared spectrometer for diagnosis of Helicobacter pylori infection

BACKGROUND AND AIM: 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.     

Validation of a simplified 13C-urea breath test method for the diagnosis of Helicobacter pylori infection]

OBJECTIVE: To validate a simplified 13C-urea breath test (13C-UBT) method for the diagnosis of H. pylori infection. MATERIAL AND METHODS: Patients referred for gastrointestinal endoscopy and biopsy were included, and a 13C-UBT was performed after a 6-hour fast. Breath samples were collected in 10 ml glass tubes before and 30 min after the simultaneous administration of 50 mg of 13C-urea and 2 g of citric acid in 200 ml of water. All breath samples were analyzed using isotope ratio mass spectrometry. The diagnosis of H. pylori infection was established with a positive culture and/or positive histology and serology. RESULTS: Eighty-eight patients were included, 49 female and 39 male with a mean age of 45 +/- 15 yrs. Fifty-one patients (57.95%) were positive and 30 (34.1%) negative for H. pylori. Seven cases (7.95%) were considered undetermined. The sensitivity, specificity, positive predictive value, and negative predictive value for 13C-UBT were 90.2, 93.3, 95.83, and 84.8%, respectively. Accuracy was 91.4%. CONCLUSIONS: The simultaneous administration of 50 mg of 13C-urea and 2 g of citric acid represents an alternative for the non-invasive diagnosis of H. pylori infection.     

Evaluation of 13C-urea breath test to confirm eradication of Helicobacter pylori]

This study aimed to evaluate the effectiveness of the 13C-urea breath test (UBT) for assessment of Helicobacter pylori eradication after treatment. One hundred twenty six patients were enrolled with 85 receiving proton pomp inhibitor based triple therapy. They were underwent upper gastrointestinal endoscopy with biopsies for diagnosis and assessment of H. pylori infection using culture, histology, rapid urease test (RUT) and 13C-UBT. Assessment of eradication needs to be performed 4 weeks or more after completion of treatment. Breath samples were taken 15 minutes after the ingestion of 100 mg 13C-urea. Breath samples were analyzed on a mass spectrometer system. The gold standard for H. pylori infection was a positive culture or positive histology + positive RUT; negative for infection was defined as negative results of all three biopsy tests. Based on ROC curves, the most appropriate cut-off value for diagnosis of H. pylori infection was identified as 2.5/1000, which provided 96.2% sensitivity, 100% specificity, and 96.8% accuracy as judged by the gold standard. However, when confirming the eradication of H. pylori, it was 3.5/1000, which provides for 100%, 95.8%, and 96.5%, respectively. Ten patients (11.8%) had delta13C values that were 2.5-5.0/1000 4-12 weeks after therapy. Eight patients were considered cured of H. pylori infection, and 2 were considered to still have H. pylori infection following 13C-UBT, serology, and H. pylori specific antigen test. The false-positive rate of 13C-UBT was 9.4% (8/85). When the grey zone of 13C-UBT was set at a level of 2.5 to 5.0/1000 (2.5 > : negative, 5.0 < or = : positive) after eradication therapy, the sensitivity and specificity of 13C-UBT was 100% and 98.4% compared to the gold standard. It was concluded that to avoid false-positive results of 13C-UBT, the grey zone of 13C-UBT needs to be set at a level of 2.5 to 5.0/1000; thus improving the accuracy of test for the assessment of eradication of H. pylori infection.     

Diagnostic accuracy of the 13C-urea breath test for childhood Helicobacter pylori infection: a multicenter Japanese study

OBJECTIVES: In adults, the 13C-urea breath test (UBT) has been widely used as a noninvasive test of Helicobacter pylori infection because of its high sensitivity and specificity. However, this test is less well established in pediatric practice. The optimum cutoff value and test protocol of the 13C-UBT remains to be established in the pediatric population. The primary purpose of this study was to evaluate diagnostic accuracy of the 13C-UBT for children and to determine its optimum cutoff value. METHODS: A total of 220 Japanese children aged 2-16 yr (mean = 11.9) who underwent upper GI endoscopy and gastric biopsies were finally studied. Endoscopic diagnoses included gastritis (n = 131), gastric ulcer (n = 15), duodenal ulcer (n = 72), and combined ulcer (n = 2). H. pylori infection status was confirmed by biopsy tests including histology, urease test, and culture. With the 13C-UBT, breath samples were obtained at baseline and at 20 min after ingestion of 13C-urea without a test meal and were analyzed by isotope ratio mass spectrometry. Based on biopsy tests, a cutoff value was determined using a receiver operating characteristic curve. In 26 children (seven children infected and 19 noninfected), paired breath samples were also measured by nondispersive infrared spectometry (NDIRS). RESULTS: Biopsy tests demonstrated that 89 children (40%) were infected with H. pylori and 131 children were not infected. There were no statistical differences in mean delta 13C values at 20 min between male and female H. pylori-infected and noninfected patients. A receiver operating characteristic analysis defined the best cutoff value as 3.5 per thousand. The overall sensitivity and specificity at a cutoff value of 3.5 per thousand were 97.8% (95% CI = 92.1-99.7%) and 98.5% (95% CI = 96.4-100%), respectively: high sensitivity and specificity were demonstrated in all three age groups (< or =5, 6-10, and > or = 11 yr). There was a close correlation between the values with isotope ratio mass spectrometry and NDIRS methods (r = 0.998, p < 0.001). CONCLUSIONS: The 13C-UBT with a cutoff value of 3.5 per thousand is an accurate diagnostic method for active H. pylori infection. The test with the NDIRS method is inexpensive and might be widely applied in clinical practice.     

红外能谱测量法20mg酸化胶囊^13C-UBT的效能评价

目的探讨剂量小于常规75～100mg、红外能谱测量法^13C-尿素呼气试验（^13C-UBT）诊断幽门螺杆菌（H．pylori）感染的可行性。方法133例因消化不良进行胃镜检查的门诊患者,胃黏膜活检标本Giemsa染色检查H．pylori,红外能谱测量法进行20mg酸化胶囊^13C-UBT,分别应用ROC法和特异性优先法评价诊断效能。结果59例H．pylori阳性病人和74例阴性病人DOB值分别为5．27±4．49和-0．50±0．98,差异显著（P〈0．05）。ROC法的最适判别值为DOB=0．4时,其诊断敏感性、特异性和准确性分别为91．5％（54／59）、89．2％（66／74）和90．2％（120／133）;以特异性优先法的最适判别值为DOB=2．0时,其诊断敏感性、特异性和准确性分别86．4％（51／59）、100％（74／74）和94．0％（125／133）。结论红外能谱测量法小剂量^13C-尿素呼气试验是可行的,但20mg酸化胶囊^13C-尿素呼气试验方案尚不能满足临床诊断需要。     

Validation of the 13C-urea breath test for the diagnosis of Helicobacter pylori infection in children: a multicenter study

OBJECTIVE: The 13C-urea breath test (13C-UBT) is a safe, noninvasive, and accurate test for the detection of Helicobacter pylori (H. pylori) infection in adults. The aim of this study was to evaluate sensitivity and specificity of 13C-UBT in children using different types of test meal, doses of 13C-urea and breath sampling intervals. As yet, a validated, standardized 13C-UBT protocol for children has not been formulated. METHODS: 13C-UBT was performed in 115 children and repeated within 3 days, modifying the test meal or the dose of 13C-urea. H. pylori status was assessed by histology and rapid urease test. 13C-UBT was performed using 100 mg or 50 mg of 13C-urea and a fatty test meal (100 FA; 50 FA), 50 mg of 13C-urea, and a carbohydrate test meal (50 CA). Breath samples were collected every 10 min for 60 min. RESULTS: The 13C-UBT in children was highly sensitive and specific with all three protocols used. The best combination of sensitivity (97.92%) and specificity (97.96%) was obtained with Protocol 50 FA at 30 min with a cut-off of 3.5 per mil. CONCLUSIONS: The 13C-UBT is an accurate test for the detection of H. pylori infection also in children. Administration of 50 mg of 13C-urea, a fatty test meal, and breath sampling at 30 min appears to be the most convenient protocol.     

Endoscopic 13C-urea breath test for detection of Helicobacter pylori infection after partial gastrectomy

BACKGROUND/AIMS: It is difficult to interpret the results of 13C-urea breath test (UBT) in gastrectomy patients because the test urea may pass through the stomach faster. The aim of this study is to evaluate the efficacy of the modified endoscopic UBT for detection of Helicobacter pylori (H. pylori) infection in the residual stomach. METHODOLOGY: An endoscopic UBT was performed in 44 patients who had undergone partial gastrectomy. At endoscopy, 20 mL of water containing 100mg of 13C-urea were sprayed onto the gastric mucosa and an intragastric gas sample was immediately collected through the biopsy channel. Breath samples were collected at 20 min after spraying 13C-urea. RESULTS: The intragastric delta13CO2 value in H. pylori-positive patients was significantly higher than those of 20-minute breath samples. The maximum sensitivity and specificity of intragastric samples were 97% and 100% with cutoff point of 5 per thousand, respectively. The sensitivity and specificity of breath samples at 20 min were 71.4% and 66.7% with cutoff point of 0.6 per thousand, respectively. CONCLUSIONS: An endoscopic UBT was superior to a standard UBT to detect H. pylori infection after partial gastrectomy.     

幽门螺杆菌感染诊断方法的比较

338例病人同时进行了快速尿素酶试验(简称RUT)。Warthin-Starry染色(简称W-S染色)、培养法、~(13)C-尿素呼气试验(~(13)C-UBT)、血清IgG、IgM等6种诊断方法中任意3种检查,以同时2种(或以上)检查方法一致的结果作为诊断幽门螺杆菌(Hp)是否存在的标准。对上述6种方法的敏感性、特异性、符合率、阳性预测值、阴性预测值分别给予评价,结果显示:RUT、W-S染色、~(13)C-UBT三法诊断Hp的敏感性、特异性等较高,均接近或高于90％。     

Accuracy of 13C-urea breath test in clinical use for diagnosis of Helicobacter pylori infection

The 13C-urea breath test (UBT) is a noninvasive test for diagnosis of Helicobacter pylori infection of gastric mucosa. The aim of this prospective study was to assess the accuracy of a simple UBT in clinical routine use. METHODS: The study population comprised of 100 patients (49 f, 51 m) requiring diagnostic upper GI endoscopy. One biopsy specimen was taken from the gastric antrum, body and fundus, respectively, for standard histological examination and one additional specimen from each location was transformed into transport medium for cultivation of H. pylori. After vaccination of the culture plates the biopsies were tested for urease activity (UAT). After recovery from endoscopy the patients had to pass an one liter endexspiratory breath sample before and 15 min after drinking 200 ml orange juice, pH 3.6, containing 75 mg of 13C-urea. 13CO2 was measured in the breath samples using isotope-selective nondispersive infrared spectrometry. RESULTS: Defining gold standard groups with all biopsy tests (from antrum and corpus) positive or negative the 13CO2 delta over baseline (DOB) cut-off level of UBT was set at 6.5/1000 in order to best discriminate positive from negative patients (ROC analysis). UBT was positive in 37% of all subjects. Taken UAT and histological examination together (positive when both tests were positive) UBT displayed a sensitivity of 92%, a specificity of 94%, a positive predictive value of 89%, and a negative predictive value of 94%. When including the results of culture sensitivity and negative predictive value reached almost 100%. The mean of the 13CO2-DOB values from H. pylori-positive duodenal or gastric ulcer patients did not differ from controls (H. pylori-positive patients without lesions). The 13CO2-DOB values of the ulcer group were correlated significantly with the active inflammatory component of gastritis in antrum, corpus, and fundus. CONCLUSION: UBT with this setup detects H. pylori infection in clinical routine use with high accuracy. The increase of exhaled 13CO2 does not predict ulcer disease but reflects the degree of active inflammation of gastric mucosa.