Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy

BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice.

Evaluation of urea breath test as a diagnostic tool for Helicobacter pylori infection in adult dyspeptic patients

In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helicobacter pylori(H.pylori)infection in humans.It is based on radionuclide-labeled urea.Various methods,both invasive and non-invasive,are available for diagnosing H.pylori infection,inclu-ding endoscopy with biopsy,serology for immunoglobulin titers,stool antigen analysis,and UBT.Several guidelines recommend UBTs as the primary choice for diagnosing H.pylori infection and for reexamining after eradication therapy.It is used to be the first choice non-invasive test due to their high accuracy,specificity,rapid results,and simplicity.Moreover,its performance remains unaffected by the distribution of H.pylori in the stomach,allowing a high flow of patients to be tested.Despite its widespread use,the performance characteristics of UBT have been inconsistently described and remain incompletely defined.There are two UBTs available with Food and Drug Administration approval:The 13C and 14C tests.Both tests are affordable and can provide real-time results.Physicians may prefer the 13C test because it is non-radioactive,compared to 14C which uses a radioactive isotope,especially in young children and pregnant women.Although there was heterogeneity among the studies regarding the diagnostic accuracy of both UBTs,13C-UBT consistently outperforms the 14C-UBT.This makes the 13C-UBT the preferred diagnostic approach.Furthermore,the provided findings of the meta-analysis emphasize the significance of precise considerations when choosing urea dosage,assessment timing,and measurement techniques for both the 13C-UBT and 14C-UBT,to enhance diagnostic precision.

Modified Helicobacter test using a new test meal and a 13C-urea breath test in Helicobacter pylori positive and negative dyspepsia patients on proton pump inhibitors

AIM To determine the sensitivity and specificity of the ^(13)C-urea breath test(UBT) in patients taking proton pump inhibitors(PPIs), using a new test meal Refex. METHODS One hundred and fourteen consecutive patients with dyspepsia, 53 Helicobacter pylori(H. pylori) positive, 49 H. pylori negative, were included in the study. The patients were then given esomeprazole 40 mg for 29 consecutive days, and the ^(13)C-UBT with the new test meal was performed the next morning. RESULTS The sensitivity of the ^(13)C-UBT with a cut off 2.5‰ was92.45%(95%CI: 81.79%-97.91%) by per-protocol(PP) analysis and 78.13 %(95%CI: 66.03%-87.49%) by intention-to-treat(ITT) analysis. The specificity of the ^(13)C-UBT test was 96.00 % in the ITT population(95%CI: 86.29%-99.51%) and 97.96% in the PP population(95%CI: 89.15%-99.95%).CONCLUSION The new test meal based ^(13)C-UBT is highly accurate in patients on PPIs and can be used in those unable to stop their PPI treatment.

Accuracy of urea breath test in Helicobacter pylori infection: Meta-analysis

AIM: To quantitatively summarize and appraise the available evidence of urea breath test(UBT) use to diagnose Helicobacter pylori(H. pylori) infection in patients with dyspepsia and provide pooled diagnostic accuracy measures.METHODS: We searched MEDLINE, EMBASE, Cochrane library and other databases for studies addressing the value of UBT in the diagnosis of H. pylori infection. We included cross-sectional studies that evaluated the diagnostic accuracy of UBT in adult patients with dyspeptic symptoms. Risk of bias was assessed using QUADAS(Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Diagnostic accuracy measures were pooled using the random-effects model. Subgroup analysis was conducted by UBT type(13C vs 14C) and by measurement technique(Infrared spectrometry vs Isotope Ratio Mass Spectrometry).RESULTS: Out of 1380 studies identified, only 23 met the eligibility criteria. Fourteen studies(61%) evaluated 13 C UBT and 9 studies(39%) evaluated 14 C UBT. There was significant variation in the type of reference standard tests used across studies.Pooled sensitivity was 0.96(95%CI: 0.95-0.97) andpooled specificity was 0.93(95%CI: 0.91-0.94). Likelihood ratio for a positive test was 12 and for a negative test was 0.05 with an area under thecurve of 0.985. Meta-analyses were associated with a significant statistical heterogeneity that remained unexplained after subgroup analysis. The included studies had a moderate risk of bias.CONCLUSION: UBT has high diagnostic accuracy for detecting H. pylori infection in patients with dyspepsia. The reliability of diagnostic meta-analytic estimates however is limited by significant heterogeneity.

Validity and cost comparison of ^(14)carbon urea breath test for diagnosis of H Pylori in dyspeptic patients

AIM: To validate and compare the cost of microdose 14C urea breath test (UBT) with histology and rapid urease test for the diagnosis of H Pylori. METHODS: Ninety-four consecutive patients with dyspeptic symptoms undergoing gastroscopy were enrolled. Gastric biopsies were taken for histology and rapid urease test. UBT was performed after gastroscopy by microdose 14C urea capsules. Sensitivity, specificity and accuracy of UBT were calculated and compared with histology and rapid urease test. Cost comparison of these tests was also performed. RESULTS: H pylori was diagnosed by histology and rapid urease test in 66 (70%) and 61 (65%) patients, while 14C UBT detected infection in 63 (67%). Accuracy of UBT was 93% in comparison with histology while its positive and negative predictive values were 97% and 84%, respectively. Comparison of 14C UBT with rapid urease test gives an accuracy of 96%, with positive and negative predictive values of 95% and 97%, respectively. These results were highly reproducible with a Kappa test (P value < 0.001). Cost of histology or rapid urease test with gastroscopy was 110 USD or 95 USD respectively while the cost of UBT was 15 USD. CONCLUSION: Microdose 14C UBT was comparable to histology and rapid urease test. 14C UBT is an economical, self sufficient and suitable test to diagnose active H pylori infection in less developed countries.

Dual therapy for third-line Helicobacter pylori eradication and urea breath test prediction

We evaluated the efficacy and tolerability of a dual therapy with rabeprazole and amoxicillin (AMX) as an empiric third-line rescue therapy. In patients with failure of first-line treatment with a proton pump inhibitor (PPI)- AMX-clarithromycin regimen and second-line treatment with the PPI-AMX-metronidazole regimen, a third-line eradication regimen with rabeprazole (10 mg q.i.d.) and AMX (500 mg q.i.d.) was prescribed for 2 wk. Eradication was confirmed by the results of the 13C-urea breath test (UBT) at 12 wk after the therapy. A total of 46 patients were included; however, two were lost to followup. The eradication rates as determined by per-protocol and intention-to-treat analyses were 65.9% and 63.0%,respectively. The pretreatment UBT results in the subjects showing eradication failure; those patients showing successful eradication comprised 32.9 ± 28.8 permil and 14.8 ± 12.8 permil, respectively. The pretreatment UBT results in the subjects with eradication failure were significantly higher than those in the patients with successful eradication (P = 0.019). A low pretreatment UBT result (≤ 28.5 permil) predicted the success of the eradication therapy with a positive predictive value of 81.3% and a sensitivity of 89.7%. Adverse effects were reported in 18.2% of the patients, mainly diarrhea and stomatitis. Dual therapy with rabeprazole and AMX appears to serve as a potential empirical third-line strategy for patients with low values on pretreatment UBT.

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 min 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.

Gender-associated differences in urea breath test for Helicobacter pylori infection referrals and results among dyspeptic patients

AIM: To verify whether there is a gender difference in the 13C-urea breath test results in a large cohort. METHODS: The test results of dyspeptic patients referred for 13C-urea breath testing between January and December, 2007 were evaluated. Testing was carried out at the health insurance organization branches and evaluated at a central laboratory in Israel. RESULTS: Of a total of 28 746 test results, 18 122 (63.04%) were from females and 10 624 (36.95%) from males. Overall, 10 188 (35.4%) results [expressed as delta over baseline (DOB)] were positive (DOB 13C > 5), 18,326 (63.7%) were negative (DOB 13C < 3.5) and 232 (0.8%) were borderline (DOB 13C 3.5-5). There was a significant difference between the total positive rate among females and males (34.8% vs 37.2%, respectively, P = 0.0003). The mean test value was increased by approximately 10 units for females compared to males (P < 0.01) and this difference was consistent for all age groups (i.e., between 10-80 years of age, P < 0.01). CONCLUSION: More females were referred to 13C-urea breath testing. More males had positive results. The mean test values were significantly higher among females of all age groups, possibly representing an increased bacterial load among females and suggesting gender-associated differences in Helicobacter pylori host interactions.

Cost effectiveness analysis of population-based serology screening and ^(13)C-Urea breath test for Helicobacter pylori to prevent gastric cancer:A markov model

AIM:To compare the costs and effectiveness of no screening and no eradication therapy, the population- based Helicobacter pylori (H pylori) serology screening with eradication therapy and 13C-Urea breath test (UBT) with eradication therapy. METHODS:A Markov model simulation was carried out in all 237 900 Chinese males with age between 35 and 44 from the perspective of the public healthcare provider in Singapore. The main outcome measures were the costs, number of gastric cancer cases prevented, life years saved, and quality-adjusted life years (QALYs) gained from screening age to death. The uncertainty surrounding the cost-effectiveness ratio was addressed by one-way sensitivity analyses. RESULTS:Compared to no screening, the incremental cost-effectiveness ratio (ICER) was $16 166 per life year saved or $13 571 per QALY gained for the serology screening, and $38 792 per life year saved and $32 525 per QALY gained for the UBT. The ICER was $477 079 per life year saved or $390 337 per QALY gained for the UBT compared to the serology screening. The cost- effectiveness of serology screening over the UBT was robust to most parameters in the model. CONCLUSION:The population-based serologyscreening for H pylori was more cost-effective than the UBT in prevention of gastric cancer in Singapore Chinese males.

^(14)C-urea breath test in patients undergoing anti-tuberculosis therapy

AIM: Urea breath test (UBT) is a non-invasive diagnostic test for detecting the presence of Helicobacter pylori(H pylori).In this study we evaluated the effect of anti-tuberculosis therapy on the results of 14C-UBT.METHODS: Patients, with the diagnosis of tuberculosis (TB) who had a positive UBT at the point of starting antiTB therapy, were included. None had a history of peptic ulcer disease or had taken antibiotics, bismuth compounds and/or PPI in the previous month, 14C-UBT was repeated at the end of the second month and the end of treatment period and one month after completion of treatment course.RESULTS: Thirty-five patients (23 males) were enrolled.14C-UBT was negative in all 35 patients (100%) at the end of the second month and remained negative in 30cases (85.7%) at the end of the treatment course. One month after completion of treatment course, UBT remained negative in 13 patients (37.1%).CONCLUSION: Our report underscores the need for caution while interpreting urea breath test results in patients undergoing anti-TB therapy. Furthermore, the combination of drugs used in this study resulted in H pylori eradication in a minority of patients.

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.

Comparison of a monoclonal antigen stool test (Hp StAR) with the ^(13)C-urea breath test in monitoring Helicobacter pylori eradication therapy

AIM: To evaluate the agreement between a mAb-based stool test (HP StAR) and the urea breath test (UBT) in monitoring (H pylori) infection after eradication therapy.METHODS: Patients with discordant results on UBT and Hp StAR underwent endoscopy with biopsies for rapid urease test, culture, and histology to confirm H pylori status.RESULTS: Among 250 patients (50±14 years), 240 (96.0%) had concordant UBT and Hp StAR tests with a significant correlation between DOB and A values (R = 0.87; P＜0.0001).The remaining 10 (4.0%) patients had discordant tests (positive Hp StAR and negative UBT) with the Hp StAR inaccurate in five cases (false positive) and UBT inaccurate in the other five cases (false negative). The 'maximal expected' sensitivity, specificity, +PV, -PV, +LR, and -LR were 91%, 100%, 100%, 97.4%, ∞, and 8.2 respectively,for the UBT, and 100%, 97.4%, 91%, 100%, 38.8, and 0,respectively, for the Hp StAR. Overall accuracy for both tests was 98%.CONCLUSION: Both the UBT and the Hp StAR are equally accurate in monitoring H pylori infection. Nowadays,the choice of the 'best' non-invasive H pylori test in the post-treatment setting should be done not only in terms of diagnostic accuracy but also in view of cost and local facilities.

Microdose (14)~C-urea breath test to diagnose Helicobacter pylori infection

A capsulated microdose 14C-urea breath test (14C-UBT) was developed to detect Helicobacter pylori (HP) infection in 137 patients (54 HP negative and 83 HP positive individuals)to whom a single dose of 3. 7ｘ 104 Bq of 14C-urea in a capsule was given. Samples of exhaled gas were collected at the sib, 10th, 15th. 20th, 25th, 30th, 45th and 60th minute after the administration and the peak value of exhaled 14CO2 was found in the samples collected at the 25th minute. This peak value was taken as the measuring point and directly expressed as Bq/mmol CO2 to develop a new detecting method. Then its results were compared with those of HP culture and histological examination. It was found that the samples collected on the 25th minute showed a sensitivity of 97. 06%, specificity of 95. 12%, positive predictive value of 97. 06% and negative predictive value of 95. 12% respectively when the mean value of 14CO2 in HP negative subjects ±3s on the 25th minute was taken as the critical value. This suggests that the capsule-based microdose 14C-UBT may replace conventional 14C-UBT using a larger dose of (1. 85-3. 7)ｘ 105 Bq for it is non-invasive, safe, rapid, accurate, simple and economic.

Breath and string test: A diagnostic package for the identification of treatment failure and antibiotic resistance of Helicobacter pylori without the necessity of upper gastrointestinal endoscopy

AIM: Helicobacter pylori ( H pylofi) resistance after failed eradication has a major impact on the outcome of a further treatment regimen. The aim of this study was to assess the validity of a non-invasive strategy using the 13C-urea breath test (UBT) and the gastric string test in identifying post-treatment resistance of Hpylori.METHODS: The UBT was routinely performed 4 to 6 wk after H pylorieradication therapy. Forty-two patients (24 females, 18 males, mean age 48 years) with a positive UBT were included in the study. A gastric string test using a capsule containing a 90 cm-long nylon fiber was performed.Before the capsule was swallowed, the free end of the string was taped to the cheek. After one hour in the stomach, the string was withdrawn. The distal 20 cm of the string was inoculated onto an agar plate and processed under microaerophilic conditions. Following the string test, upper gastrointestinal endoscopy was performed to obtain gastric biopsies for conventional culture.RESULTS: H pyloriwas successfully cultured from the gastric string in 34 patients (81%), but not in 5 patients due to contamination with oropharyngeal flora. Hpyloriwas cultured from the gastric biopsies obtained at endoscopy in 39 patients (93%).CONCLUSION: The UBT followed by the gastric string test in the case of treatment failure is a valid diagnostic strategy with the aim of determining the post-therapeutic antibiotic resistance of Hpyloriwith little inconvenience to the patient.Upper GI-endoscopy can be avoided in several cases by applying consequently this diagnostic package.

样本采集时间对老年慢性胃炎患者^(13)C-尿素呼气试验结果的影响

目的:分析样本采集时间对老年慢性胃炎患者^(13)C-尿素呼气试验结果的影响。方法:选取2019年6月—2021年6月山东省荣军总医院收治的150例老年慢性胃炎患者作为研究对象。所有患者于空腹及餐后3 h进行^(13)C-尿素呼气试验,并以快速尿素酶检测结果作为“金标准”,比较两个样本采集时间^(13)C-尿素呼气试验结果的准确率、特异度及灵敏度。结果:空腹时采集样本的^(13)C-尿素呼气试验准确率、灵敏度高于餐后3 h,差异有统计学意义(P<0.05)。结论:老年慢性胃炎患者空腹时进行^(13)C-尿素呼气试验的诊断效能较高。

体检人群幽门螺杆菌感染检测意愿调查

目的探讨体检人群对H.pylori感染检测的主动性及其对检测方式的倾向性。方法于2022年9月至2022年12月在国内两家综合性三甲医院的体检人员中发放电子调查问卷,问卷内容包括受访者对H.pylori感染及检测方式的了解情况,主动给自己及家中老人、儿童(<14岁)检测的意愿,及其对尿素呼气试验(urea breath test,UBT)和H.pylori粪便抗原试验(H.pylori stool antigen test,HpSAT)的比较与选择等。结果共回收488份有效问卷。消化道症状或疾病在体检人群(57.0%)及其家庭成员(35.5%)中普遍存在。体检人群对H.pylori感染的熟悉率仅为11.9%。43.0%受访者会在体检时主动检测,36.9%的受访者在医师建议下才会进行检测,而20.1%不会主动检测。影响检测主动性的因素主要是对H.pylori感染的了解程度。对于家中老人和儿童的检测,大部分体检人员需要医师建议才会进行检测。体检人员选择检测方式时,主要看其重准确性、方便性、安全性,超过80%体检人员会选择UBT。结论体检人群对H.pylori感染的认知水平较低,但检测意愿性较强,在检测时倾向于选择传统的UBT,对新兴的快速HpSAT缺乏了解。

三亚市自然人群幽门螺杆菌感染情况分析

目的探讨三亚市自然人群幽门螺杆菌(H.pylori)感染现状,分析其影响因素,为防控H.pylori感染提供参考依据。方法采用整体分层随机抽样的方法选取三亚市四个区共677名居民,进行尿素^(14)C呼气试验和问卷调查,计算自然人群H.pylori阳性率,并分析H.pylori感染的影响因素。结果共纳入606名居民,H.pylori阳性检出者为261例,阳性检出率为38.5%。其中不同民族、婚姻状况、吸烟、进食蔬菜瓜果和文化程度与H.pylori感染相关(P<0.05);性别、年龄、BMI、饮酒、饮用水来源、咀嚼槟榔及同住人口数量与H.pylori感染无明显相关(P>0.05)。家人感染是三亚市自然人群H.pylori感染的独立危险因素,黎族、经常食用瓜果蔬菜、大专及以上文化水平是三亚市自然人群H.pylori感染的独立保护因素。结论三亚市自然人群H.pylori感染率低于全国平均水平,多食用瓜果蔬菜、提高卫生防护意识有利于预防H.pylori感染;推广家庭和相关成员同检同治,避免家庭内部聚集性感染。

Influence of proton pump inhibitor treatment on Helicobacter pylori stool antigen test

AIM: To investigate the effects of proton pump inhibitor (PPI) treatment on stool antigen test using the TestMate pylori enzyme immunoassay. METHODS: This study assessed 28 patients [16 men and 12 women; mean age (63.1 ± 5.9) years; range, 25-84 years] who underwent stool antigen test and urea breath test (UBT) before and after PPI administration. RESULTS: Using the UBT as the standard, the sensitivity, specif icity and agreement of the stool antigen test in all 28 patients were 95.2%, 71.4%, and 89.3%, respectively, before PPI administration, and 88.9%, 90.9%, and 89.3%, respectively, after PPI treatment. Mean UBT values were 23.98% ± 5.33% before and 16.19% ± 4.75% after PPI treatment and, in 15 patients treated for ≥ 4 wk, were signif icantly lower after than before 4 wk of PPI treatment (12.58% ± 4.49% vs 24.53% ± 8.53%, P = 0.048). The mean optical density (A450/630) ratios on the stool antigen test were 1.16 ± 0.20 before and 1.17 ± 0.24 after PPI treatment (P = 0.989), and were 1.02 ± 0.26 and 0.69 ± 0.28, respectively, in the group treated for > 4 wk (P = 0.099).

Diagnostic accuracy of tests for Helicobacter pylori in an Alaska Native population

AIM:To evaluate the accuracy of two non-invasivetests in a population of Alaska Native persons. Highrates of Helico bacter pylori(H. pylori) infection,H. pylori treatment failure,and gastric cancer in this population necessitate documentation of infection status atmultiple time points over a patient's life.METHODS:In 280 patients undergoing endoscopy,H. pylori was diagnosed by culture,histology,rapidurease test,13C urea breath test(UBT) ,and immuno-globulin G antibodies to H. pylori in serum. The performances of 13C-UBT and antibody test were compared to a gold standard defined by a positive H. pylori testby culture or,in case of a negative culture result,bypositive histology and a positive rapid urease test.RESULTS:The sensitivity and specificity of the 13C-UBT were 93% and 88%,respectively,relative to thegold standard. The antibody test had an equivalents ensitivity of 93% with a reduced specificity of 68%.The false positive results for the antibody test were as-sociated with previous treatment for an H. pylori infection [relative risk(RR) = 2.8]. High levels of antibodiesto H. pylori were associated with chronic gastritis and male gender,while high scores in the 13C-UBT testwere associated with older age and with the H. pyloribacteria load on histological examination(RR = 4.4) .CONCLUSION:The 13C-UBT out performed the anti-body test for H. pylori and could be used when a non-invasive test is clinically necessary to document treatment out come or when monitoring for reinfection.