An optimized ^(13)C-urea breath test for the diagnosis of H pylori infection

AIM： To validate an optimized ^13C-urea breath test （^13C-UBT） protocol for the diagnosis of H pylori infection that is cost-efficient and maintains excellent diagnostic accuracy. METHODS： 70 healthy volunteers were tested with two simplified ^13C-UBT protocols, with test meal （Protocol 2） and without test meal （Protocol 1）. Breath samples were collected at 10, 20 and 30 rain after ingestion of 50 mg ^13C-urea dissolved in 10 mL of water, taken as a single swallow, followed by 200 mL of water （pH 6.0） and a circular motion around the waistline to homogenize the urea solution. Performance of both protocols was analyzed at various cut-off values. Results were validated against the European protocol. RESULTS： According to the reference protocol, 65.7% individuals were positive for H pylori infection and 34.3% were negative. There were no significant differences in the ability of both protocols to correctly identify positive and negative H pylori individuals. However, only Protocol 1 with no test meal achieved accuracy, sensitivity, specificity, positive and negative predictive values of 100%. The highest values achieved by Protocol 2 were 98.57%, 97.83%, 100%, 100% and 100%, respectively.CONCLUSION： A 10 min, 50 mg ^13C-UBT with no test meal using a cut-off value of 2-2.5 is a highly accurate test for the diagnosis of H pylori infection at a reduced cost.

Capsule ^(13)C-urea breath test for the diagnosis of Helicobacter pylori infection

AIM: To compare the accuracy of capsule 13C-urea breath test (UBT) with conventional invasive methods for the diagnosis of Helicobacter pylori infection.METHODS: One hundred patients received CLO test,histological examination, culture and 100- or 50-mg capsule UBT for the diagnosis of Hpyloriinfection. Hpylori infection was defined as those with positive culture or positive results from both histology and CLO test.RESULTS: Both the sensitivity and specificity of the 100-mg capsule UBT (n = 50) were 100%. The sensitivity and specificity of the 50-mg capsule UBT (n = 50) were 96.4and 100%, respectively. Taken together, the accuracy of capsule UBT (n=100) was higher than that of CLO test,histology and culture (100% vs 92%, 91% and 89%,respectively; P= 0.035, 0.018 and 0.005, respectively). Our data showed that the optimal timing of sampling for 100-and 50-mg capsule UBT was 15-30 and 6-15 min, respectively.CONCLUSION: Capsule UBT has a higher accuracy compared with biopsy-based tests. It is an ideal method for the diagnosis of Hpyloriinfection.

Effect of posture on ^(13)C-urea breath test in partial gastrectomy patients

AIM: To investigate whether posture affects the accuracy of 13C-urea breath test(13C-UBT) for Helicobacter pylori(H. pylori) detection in partial gastrectomy patients. METHODS: We studied 156 consecutive residual stomach patients, including 76 with H. pylori infection(infection group) and 80 without H. pylori infection(control group). H. pylori infection was confirmed if both the rapid urease test and histology were positive during gastroscopy. The two groups were divided into four subgroups according to patients' posture during the 13C-UBT: subgroup A, sitting position; subgroup B, supine position; subgroup C, right lateral recumbent position; and subgroup D, left lateral recumbent position. Each subject underwent the following modified 13C-UBT: 75 mg of 13C-urea(powder) in 100 m L of citric acid solution was administered, and a mouth wash was performed immediately; breath samples were then collected at baseline and at 5-min intervals up to 30 min while the position was maintained. Seven breathsamples were collected for each subject. The cutoff value was 2.0‰.RESULTS: The mean delta over baseline(DOB) values in the subgroups of the infection group were similar at 5 min(P > 0.05) and significantly higher than those in the corresponding control subgroups at all time points(P < 0.01). In the infection group, the mean DOB values in subgroup A were higher than those in other subgroups within 10 min and peaked at the 10-min point(12.4‰± 2.4‰). The values in subgroups B and C both reached their peaks at 15 min(B, 13.9‰± 1.5‰; C, 12.2‰± 1.7‰) and then decreased gradually until the 30-min point. In subgroup D, the value peaked at 20 min(14.7‰± 1.7‰). Significant differences were found between the values in subgroups D and B at both 25 min(t = 2.093, P = 0.043) and 30 min(t = 2.141, P = 0.039). At 30 min, the value in subgroup D was also significantly different from those in subgroups A and C(D vs C: t = 6.325, P = 0.000; D vs A: t = 5.912, P = 0.000). The mean DOB values of subjects with Billroth Ⅰ anastomosis were higher than those of subjects with Billroth Ⅱ anastomosis irrespectively of the detection time and posture(P > 0.05).CONCLUSION: Utilization of the left lateral recumbent position during the procedure and when collecting the last breath sample may improve the diagnostic accuracy of the 13C-UBT in partial gastrectomy patients.

^(13)C-尿素呼气试验诊断幽门螺杆菌感染的研究

本研究旨在评估^(13)C,尿素呼气试验检测幽门螺杆菌感染的可靠性。方法:我们在82例因胃病而行胃镜检查的患者胃窦和胃体取多个活检标本,作组织学、牯膜涂片和快速尿素酶试验,以决定是否感染幽门螺杆菌,并作^(13)C-尿素呼气试验。^(13)C-尿素呼气试验的敏感性、特异性、阳性预测值、阴性预测值是与组织学和尿素酶方法检测幽门螺杆菌的结果比较而计算得到。结果:^(13)C-尿素呼气试验的敏感性97.92％,特异性100％,阳性预测值100％,阴性预测值97.14％,准确性98.78％。结论:^(13)C-尿素呼气试验有高度敏感性和特异性,对确定患者的幽门螺杆菌感染状态是一可靠的无创伤的诊断方法。

^(13)C-UBT检测幽门螺杆菌4871例临床分析

目的:初步探讨幽门螺杆菌相关疾病病因及感染率。方法:利用13C呼气试验检测幽门螺杆菌感染率。结果:13C呼气试验检测幽门螺杆菌具有简单方便、无创伤性、无放射性、可反复、先进、即时、灵敏、特异、快速特点。结论:13C呼气试验值得临床推广。

Epidemiological investigation of Helicobacter pylori infection in elderly people in Beijing

BACKGROUND The Helicobacter pylori(H.pylori)infection rate in China is approximately 50%.H.pylori is a pathogenic factor of peptic ulcer and chronic gastritis.In addition,H.pylori infection may also be associated with a variety of cardiovascular diseases in elderly people,such as arteriosclerosis,coronary heart disease,and cerebral infarction,having deleterious effect on their health.With the aging of the population,the disease characteristics of the elderly population have been increasingly valued by the whole society.We conducted an epidemiological survey of H.pylori infection among elderly people in Beijing to provide a basis for health management of H.pylori infection.AIM To understand the epidemiological characteristics of H.pylori infection in elderly people in Beijing.METHODS A total of 1090 elderly people aged more than 60 years from different parts of Beijing(urban and rural areas)were selected using the random cluster sampling method.Structured questionnaires were completed during home visits and the 13C-urea breath test was conducted for H.pylori detection.RESULTS The prevalence of H.pylori infection was 46.5%(507/1090).The infection rate in men was 51.8%,which was significantly higher than that in women(42.5%;P<0.05).The H.pylori infection rate in illiterate people was significantly higher than that in literate persons(53.5%vs 44.8%,P<0.05).The total infection rate of H.pylori gradually increased with age and the difference was statistically significant(P<0.01).The H.pylori infection rate in smokers was significantly higher than that in non-smokers and those who had quit smoking(P<0.05).CONCLUSION The prevalence of H.pylori infection among elderly people is 46.5%and the infection rate gradually increases with age.Sex,education level,age,and smoking were determined to be H.pylori infection risk factors.The relationship of H.pylori infection with region,occupation,drinking,and diet structure needs to be further studied.

Blood pressure and stature in Helicobacter pylori positive and negative persons

To evaluate vital signs and body indices in Helicobacter pylori (H. pylori) positive and negative persons. A total of 22 centres entered the study. They were spread over the whole country, corresponding well to the geographical distribution of the Czech population. A total of 1818 subjects (aged 5-98 years) took part in the study, randomly selected out of 38147 subjects. H. pylori infection was investigated by means of a 13C-urea breath test. Data on height, weight, systolic and diastolic blood pressure and heart rate were collected at the clinics of general practitioners. The overall prevalence of H. pylori infection was 30.4% (402/1321) in adults (≥ 18 year-old) and 5.2% (26/497) in children and adolescents (≤ 17 year-old). Once adjusted for age and gender, only a difference in body mass index remained statistically significant with H. pylori positive adults showing an increase of 0.6 kg/m2 in body mass index. Once adjusted for age and gender, we found a difference in height between H. pylori positive and H. pylori negative children and adolescents. On further adjustment for place of residence, this difference became statistically significant, with H. pylori positive children and adolescents being on average 3.5 cm shorter. H. pylori positive adults were significantly older compared to H. pylori negative subjects. Once adjusted for age and gender, H. pylori infection had no impact on body weight, body mass index and vital signs either in adults or children and adolescents. Chronic H. pylori infection appeared to be associated with short stature in children. H. pylori infection did not influence blood pressure, body weight and body mass index either in adults or children and adolescents.

Scintigraphic evaluation of gallbladder motor functions in H pylori positive and negative patients in the stomach with dyspepsia

AIM:To evaluate the relationship between gallbladder (GB) motor function and H pylori infection in the stomach. METHODS: All cases (86) underwent the 14C urea breath test (UBT). 14C-UBT was found as positive in 58 and negative in 28 dyspeptic patients. 14C- UBT was accepted as a gold standard test. Clo test and histopathologic examination were compared with the results of 14C-UBT in cases who tolerated upper gastrointestinal endoscopy procedure. Cholescintigraphy with 99mTc-mebrofenin was used to determine the parameters of GB motor function (GB filling and emptying time, half of the emptying time, ejection fraction at 30th and 60th min) in all patients. RESULTS: We found the sensitivity and specificity as 88% and 86% for Clo test and as 89% and 80% for histologic evaluation, respectively. The parameters of GB function were not significantly different in H pylori positive and negative patients. The GB emptying was normal in both groups. Minimum GB filling time was 30 min in 34 of 86 cases (39.5%), filling was not observed in 2 cases. The GB ultrasonography (USG) results were normal for all cases and bile composition abnormality was not determined.CONCLUSION: Our study showed that 14C-UBT is highly reliable method to detect the presence of H pylori. The presence of H pylori infection does not directly affect the GB function.

Significant decrease in prevalence ofHelicobacter pylori in the Czech Republic

AIM:To study possible decrease in prevalence of Helicobacter pylori(H.pylori) infection in the Czech Republic within a 10-year period.METHODS:A total of 22 centres entered the study.The catchment areas of these centres covered cities and towns with more than 20 000 inhabitants,smaller towns(≤ 20 000 inhabitants) with surrounding villages and rural areas,and were spread over the whole country,corresponding well to the geographical distribution of the Czech population.A total of 1 837 subjects(aged 5-98 years) took part in the study,randomly selected out of 38 147 people from the general population.H.pylori infection was investigated by means of a 13 C-urea breath test.Breath samples in duplicates were analysed using isotope ratio mass spectrometry.The cut-off point was 3.5.Social and demographic characteristics were based on data from self-completed questionnaires.RESULTS:The overall prevalence of H.pylori infection was 23.5%(430/1826),and 4.8%(20/420) in children aged 15 or less.There was no statistically significant difference in prevalence between males(24.3%;208/857) and females(22.9%,222/969,P = 0.494).H.pylori infection was strongly associated with higher age,among subjects aged 55+ years,prevalence of H.pylori infection was 39.8%(252/633,P < 0.001).The highest prevalence of H.pylori infection was found among persons aged 55-64 years(43.9%,97/221) and 75+ years(37.9%,58/153).Among study subjects aged 15+ years,prevalence of H.pylori infection was significantly increased in those with lowest education(odds risk 3.19,95% CI 1.87-5.47).Compared to never married(14.1%),the prevalence of H.pylori infection was statistically significantly higher among married(35.4%,246/694,P < 0.001),divorced(36.8%,49/133,P < 0.001) and widowed study subjects(40.2%,45/112,P < 0.001),both in minimally and fully adjusted analysis.There was no significant difference in the prevalence of H.pylori infection between married and widowed subjects(35.4%,246/694 vs 40.2%,45/112,P = 0.389).There was little variation in smoking prevalence across categories of smoking and there was no evidence of an increased risk ofH.pylori infection among current or past smokers in our data(odds risk 1.04 with 95% CI 0.78-1.40 for current smokers;odds ratio 0.83 with 95% CI 0.60-1.16 for former smokers).The current prevalence of H.pylori in 2011 was significantly lower compared to the prevalence reported from identical geographical areas in 2001(23.5%vs 41.7%,P < 0.001).CONCLUSION:The overall prevalence of H.pylori infection in the general population has fallen substantially in the Czech Republic over the past 10 years.

Diagnosis of Helicobacter pylori infection:A meta-analysis

Objective:To evaluate effects of diagnostic tests for Helicobacter pylori(H.pylori)infec- tion.Methods:A meta-analysis was conducted in 22 identified studies through Chinese literature searching which were published after 1995 and evaluated diagnostic tests for Helicobacter pylori(H.pylori)infec- tion.Results:Polymerase chain reaction(PCR)had the best performance with diagnostic odds ratio (DOR)of 6.7(5.5-7.8),followed by ^(13)C urea breath test and Enzyme-linked immunosorbent assay (ELISA)quantitative serological test,with DOR being 6.4(5.4-7.4)and 4.5(3.8-5.2),respectively. Conclusion:Non-invasive tests are the appropriate methods for screening H.pylori infection,whereas in- vasive tests are the best methods for ascertaining the suspected patients.