Accuracy Of Urea Breath Test Research Articles

Non-invasive diagnostic tests for Helicobacter pylori infection.

Non-invasive diagnostic tests for Helicobacter pylori infection.

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

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. 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). Out of 1380 studies identified, only 23 met the eligibility criteria. Fourteen studies (61%) evaluated 13C UBT and 9 studies (39%) evaluated 14C 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. 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.

Accuracy of Urea Breath Test Performed Immediately After Emergency Endoscopy in Peptic Ulcer Bleeding

The aim of this work is to investigate the accuracy of the urea breath test (UBT) performed immediately after emergency endoscopy in peptic ulcer bleeding (PUB). Urea breath test was carried out right after emergency endoscopy in patients with PUB. The accuracy of this early UBT was compared to a delayed one after hospital discharge that was considered the gold standard. Clinical and epidemiological factors were analyzed in order to study their influence on the accuracy of the early UBT. Early UBT was collected without any complication and good acceptance from all the 74 patients included. In 53 of the patients (71.6%), a delayed UBT was obtained. Comparing concordance between the two tests we have calculated an accuracy of 83% for the early UBT. Sensibility and specificity were 86.36 and 66%, respectively, with a positive predictive value of 92.68% and negative predictive value of 50% (Kappa index = 0.468; p = 0.0005; CI: 95%). We found no influence of epidemiological factors, clinical presentation, drugs, times to gastroscopy, Forrest classification, endoscopic therapy, hemoglobin, and urea levels over the accuracy of early UBT. Urea breath test carried out right after emergency endoscopy in PUB is an effective, safe, and easy-to-perform procedure. The accuracy of the test is not modified by clinical or epidemiological factors, ulcer stage, or by the type of therapy applied. However, we have found a low negative predictive value for early UBT, so a delayed test is mandatory for all negative cases.

Effect of omeprazole, rabeprazole, and rebamipide on the accuracy of urea breath test in patients with Helicobacter pylori infection

Abstract Background: The urea breath test (UBT) has been widely used for H. pylori eradication after treatment. The breath test could be adversely affected by various factors including proton pump inhibitors (PPIs) that are also used in the therapy for H. pylori infection. Objective: Determine the effect of omeprazole, rabeprazole and the mucoprotective agent rebamipide, on the UBT. Methods: Fifty-six patients with dyspepsia and positive for H. pylori by rapid urease test were enrolled. They were classified into three groups: Group 1 (n=25) received omeprazole 20 mg once daily, group 2 (n=13) received rabeprazole 20 mg once daily, and group 3 (n=18) received rebamipide 100 mg three times a day. All patients received a 14-day course of their medications. UBT was performed on day 0 as a baseline and on day 14 in all patients. In patient with negative results of UBT on day 14, the UBT was performed in consecutive week until the test became positive. Results: Fifty-six patients (20 men and 36 women) participated in the study. Their mean age was 46.77±14.3 years. False negative rate after 14-day treatment in omeprazole, rabeprazole and rebamipide group were 20.0%, 30.8%, and 0% respectively. There was a significant difference between 13C level in patients with negative and positive UBT results (2.7±0.7 vs.22.9±3.7/mL, p=0.025). The reversal of false negative to true positive tests occurred within two weeks after discontinuation of omeprazole and rabeprazole. Conclusion: Proton pump inhibitors had an effect on the accuracy of H. pylori detection using UBT. Rabeprazole revealed a higher false negative rate in the UBT than omeprazole. The mucoprotective drug, rebamipide, did not influence negative results in the UBT.

Bismuth Salts in the Treatment of Helicobacter pylori Infection in Children

Delghani et al. [1] evaluated the efficacy of three different regimens for eradication of Helicobacter pylori (H. pylori) infection in children. The authors concluded that quadruple therapy containing bismuth yields better results and can be used as first-line of therapy. The study is both well designed and well managed, and highlights the need for novel therapies in children with H. pylori infection. Here are some important points of the study that should be discussed. The study group was composed of 120 children with a mean age of 12 ± 4 years (range 2–18 years). H. pylori eradication was assessed with urea breath test (UBT). The utility of UBT in children over 6 years of age was confirmed by numerous studies. The sensitivity and specificity for children in this group were found to be 100 and 98% respectively, with positive predictive value (PPV) and negative predictive values (NPV) of 98 and 100% respectively. In young children, however, false-positive results compromise the accuracy of the test. For children under the age of 6 years, specificity was determined to be 88% and PPV 69% [2]. The accuracy of UBT can be improved by increasing delta over baseline (DOB) cut-off values; however, the false-positive rate remains high [2, 3]. It would be better to provide brief methodologic data regarding UBT including information at least about cut-off values and whether values are adjusted for age. The authors reported the eradication rate with quadruple therapy with bismuth 91.8% compared to 82.1 and 80.5% with current triple therapies containing clarithromycin in the second group and metronidazole in third group, respectively. The authors suggested quadruple therapy as the first-line of therapy for the eradication of H. pylori infection in children in their geographic area. Treatment of H. pylori infection in children with protocols containing bismuth compounds have been reported with variable success [4–7]. In a recent report of pooled data [8], bismuth triple therapies were found to be more efficacious than proton pump inhibitor triple therapies (77 vs. 64%) as a first-line treatment. Indeed, the eradication rate is better with quadruple therapy in the present study, but not sufficiently high to suggest it as a first-line therapy (p = 0.33). Secondly, bismuth compounds are major drugs of rescue regimens after H. pylori treatment failure. The most important cause of treatment failure is drug resistance. In this case, it is fairly logical to reserve bismuth compounds as a second-line option to decrease the risk of drug resistance. Although the use of bismuth compounds has been reported in children [8], they still require approval to use. Therefore, the use of bismuth compounds in children may be of ethical concern. In adults, it has recently been suggested that fluoroquinolone-based rescue therapies constitute an encouraging second-line strategy, representing an alternative to quadruple therapy with efficacy, simplicity, and safety [9–11]. Although pediatric data is limited, fluoroquinolone-based therapies can be tried as rescue therapy in children over the age of 8 [12]. Lastly, compliance is an important determinant of treatment success. Multiple drug use is an important risk factor and therefore compliance is expected to be low with quadruple therapy. In conclusion, it is still too early to suggest quadruple therapy containing bismuth compounds as a first-line option in children with H. pylori infection. Moreover, we need further comparable studies in order to determine the case for quadruple therapies containing bismuth compounds as a second-line option. S. Gokce (&) Pediatric Gastroenterology, Hepatology and Nutrition, Dr. Sami Ulus Children’s Hospital, Ankara, Turkey e-mail: drgokce0007@yahoo.com

Validity and cost comparison of14carbon urea breath test for diagnosis ofH Pyloriin dyspeptic patients

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. 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. 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. 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.

13C-urea breath test in the management of Helicobacterpylori infection

The urea breath test is a noninvasive and very accurate test for the diagnosis of Helicobacter pylori infection. However, false negative urea breath test results have been reported to occur in a considerable percentage of the individuals taking proton pump inhibitors; the interval needed to be completely confident that false negative tests had been excluded has varied among the different studies between 6 and 14 days. The impact of H 2-receptor antagonists on the accuracy of urea breath test remains controversial, although, in contrast with proton pump inhibitors, the data suggest that H 2-receptor antagonists, for the most part, have little effect on the result of the urea breath test. The urea breath test does not represent a suitable tool for estimating the density of H. pylori colonization. The only quantitative information to be obtained from the urea breath test is that the higher the δ value, the lower the probability of a false-positive urea breath test result. Although some authors have demonstrated a correlation between urea breath test values and histological lesions of the gastric mucosa, the practical utility of this relationship remains unclear. It has been suggested that the pretreatment urea breath test has the potential to identify patients who require modification of the standard therapeutic regimen (for example, prolonging the duration of treatment or increasing the pharmacological dose when bacterial density is high), but other studies could not confirm this relationship. Some studies have shown that the urea breath test is less accurate in patients who have undergone partial gastrectomy. Finally, in contrast with biopsy-based methods, which are responsible for a high number of false-negative results when used to diagnose H. pylori infection in patients with upper gastrointestinal bleeding, urea breath test seems not to be negatively influenced by the presence of this complication.

Selection of lower cutoff point of [13C]urea breath test is helpful to monitor H. pylori eradication after proton pump inhibitor-based triple therapy.

Our objectives were to test the efficacy of [13C] urea breath test (UBT) for H. pylori infection in patients before and after proton pump inhibitor (PPI) based triple therapy, and thus to trace the optimal cutoff value of UBT to monitor H. pylori eradication; and to analyze the histologic bacterial density and distribution of H. pylori in patients with equivocal UBT. A total of 441 dyspeptic cases patients enrolled and completed the study design, including 120 noninfected and 321 H. pylori-infected patients. All 441 cases had received the same protocol of UBT. in which the baseline and 15-min gas samples after ingestion of 100 mg 13C-labeled urea were analyzed for excess 13CO2/12CO2 ratio (ECR). In addition, a first endoscopy was performed in each patient to evaluate the initial status of H. pylori by culture and histology. Of the 321 H. pylori-infected patients, 286 received a second endoscopy and a second UBT six weeks after completing any one of four regimens of the PPI-based triple therapy to document the success of H. pylori eradication. During both sessions of endoscopy, topographic gastric biopsies for histology were sampled to evaluate the distribution and density of H. pylori. Based on the diagnostic standard by culture and histology, the sensitivity and specificity of the first UBT achieved most optimally was 97.5% and 96.7%, respectively, by setting the cutoff point of ECR at 4.0. In contrast, using the same cutoff point of 4.0, the sensitivity and specificity of the second UBT in patients after therapy achieved just 80% and 97.6%, respectively. By applying cutoff points downward of 4.0, 3.5, 3, and 2.5 for the second UBT, the sensitivity was elevated to 80%, 82.8%, 88.6%, and 94.3%, respectively, while the specificity was preserved at more than 95.2%. The overall eradication rate of H. pylori was 87.8% (251/286). Seven of 35 patients with failure of therapy had equivocal ECR at the second UBT (range 2-5), and this accounted for the false negative result. All seven patients had low bacterial densities, and three patients had bacteria distributed only in high body near the cardia. In conclusion, selection of a lower cutoff value of ECR at 2.5 is helpful to maintain the diagnostic accuracy of UBT for monitoring the H. pylori eradication. The equivocal ECR of UBT after therapy would be related to the low bacterial load and its distribution.