Clinical Validation of an Office-Based C-UBT (Heliprobe) for H. pylori Diagnosis in Iranian Dyspeptic Patients. Gastroenterol Res Pract. 2011;2011:930941. [PMID: 21760778 PMCID: PMC3132501 DOI: 10.1155/2011/930941]

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 (13C-UBT or 14C-UBT) against a reference standard. We used the QUADAS-2 tool to assess the methodological 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.

RESULTS

The titles and abstracts of 4621 studies were screened; 79 articles were retrieved and selected for full-text reading. Finally, 60 studies were included in the diagnostic test accuracy meta-analysis. Our analysis demonstrates superior diagnostic accuracy of 13C-UBT over 14C-UBT, indicated by higher sensitivity (96.60% vs 96.15%), specificity (96.93% vs 89.84%), likelihood ratios (LR+ 22.00 vs 10.10; LR- 0.05 vs 0.06), and area under the curve (AUC; 0.979 vs 0.968). Notably, 13C-UBT's DOR (586.47) significantly outperforms 14C-UBT (DOR 226.50), making it the preferred diagnostic tool for dyspeptic individuals with H. pylori infection. Correlation analysis revealed no threshold effect (13C-UBT: r = 0.48; 14C-UBT: r = -0.01), and SROC curves showed consistent accuracy. Both 13C-UBT and 14C-UBT showed high AUC values (13C-UBT 0.979; 14C-UBT 0.968) near 1.00, reinforcing their excellent accuracy and endorsing both as reliable diagnostic tools in clinical practice.

CONCLUSION

In summary, our study has demonstrated that 13C-UBT has been found to outperform the 14C-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.

Lactobacillus ruteri compared with placebo as an adjuvant in quadruple therapy for Helicobacter pylori eradication: A randomized, double-blind, controlled trial

BACKGROUND AND STUDY AIMS

The aim of this study was to evaluate the efficacy of probiotic as an adjuvant in quadruple therapy for H. pylori eradication compared with placebo.

PATIENTS AND METHODS

This randomized, double-blind, controlled trial was conducted on 450 patients with confirmed H. pylori infection. We randomly allocated patients (1:1) to receive probiotic (Lactobacillus ruteri, 100 mg) or placebo as an adjuvant in quadruple therapy with bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg and clarithromycin 500 mg all twice daily for 14 days. The primary outcome of the study was the H. pylori eradication rate at eight weeks after the end of treatment using ¹⁴C-urea breath test. The secondary endpoint of study was patient-reported side effects of drugs. The study protocol was approved by the Iranian Registry of Clinical Trials (IRCT20080901001155N32).

RESULTS

H. pylori eradication rates were higher in the probiotic group, compared to placebo, but this difference was not statistically significant, according to both intention-to-treat (78.7 % (95 % CI; 71.24-86.16) versus 72 % (95 % CI; 64.9-79.1), respectively) and per-protocol (80.1 % (95 % CI; 73.7 - 86.5) versus 75.2 %(95 % CI; 68.4 - 82), respectively). About 69.7 % of patients in the probiotic group experience side effects compared to 98.6 % in the placebo group that was statistically significant (P-value < 0.001). Headache and all gastrointestinal adverse events except constipation were significantly lower in the probiotic group compared to placebo (P-value < 0.001).

CONCLUSION

Adding Lactobacillus ruteri to quadruple therapy did not significantly improve the eradication of H. pylori. However it reduced the frequency of drug-associated side effects.

Diagnostic Value of 14C Urea Breath Test for Helicobacter pylori Detection Compared by Histopathology in Indonesian Dyspeptic Patients

PURPOSE

Histopathology method is often used as a gold standard diagnostic for Helicobacter pylori infection in Indonesia. However, it requires an endoscopic procedure which is limited in Indonesia. A non-invasive method, such as 14C Urea Breath Test (UBT), is more favorable; however, this particular method has not been validated yet.

PATIENTS AND METHODS

A total of 55 dyspeptic patients underwent gastroscopy and 14C-UBT test. We used Heliprobe® UBT for UBT test. As for the histology, May-Giemsa staining of two gastric biopsies (from the antrum and corpus) were evaluated following the Updated Sydney System.

RESULTS

The Receiver Operating Characteristics analysis showed that the optimum cut-off value was 57 with excellence Area under Curve = 0.955 (95% CI = 0.861-1.000). By applying the optimum cut-off value, Heliprobe® UBT showed 92.31% for sensitivity, 97.62% for specificity, 92.31% for positive predictive value, 97.62% for negative predictive value, 38.77 for positive likelihood ratio, 0.0788 for negative likelihood ratio, and 96.36% for the accuracy.

CONCLUSION

The 14C-UBT is an accurate test for H. pylori diagnosis with excellent sensitivity, specificity, and accuracy. The different optimum cut-off points suggested that a validation is absolutely necessary for new test prior application to the new population.

Stool Antigen Testing, a Reliable Noninvasive Method of Assessment of Helicobacter pylori Infection Among Patients with Gastro-duodenal Disorders in Cameroon

BACKGROUND

Several techniques such as invasive and noninvasive are used for the diagnosis of H. pylori infection.

AIM

The aim of this study was to compare the results of rapid urease test, stool antigen test and serology in diagnosing H. pylori infection in Cameroon.

METHODS

Hundred patients (66 women and 34 men) were enrolled. Each patient gave a written consent. The study was approved by the local Ethical Committee of Medical Sciences and the institutional review board. From each patient, blood, stool and gastric biopsies samples were collected for H. pylori detection using three methods: stool antigen test, serology and rapid urease test (RUT), taken as gold standard. Statistical analysis was performed using Graph pad Prism 7.

RESULTS

Helicobacter pylori infection was detected in 43%, 45% and 73% of patients based on the RUT, stool antigen test and serology, respectively. The difference was statistically significant between serology and RUT (P = 0.0026), but not between stool antigens test and RUT (P = 0.288). Taken RUT as gold standard, the sensitivity, specificity, positive and negative predictive values of stool antigens test and serology were 65.11, 70.17, 62.22 and 72.72%; 88.37, 40.35, 55.77 and 82.14%, respectively. The accuracy of stool antigen test and serology was 68 and 61%, respectively.

CONCLUSIONS

Our finding showed that stool antigen test can be used as a noninvasive method of assessment of H. pylori infection in our setting. Serological test can be used in screening; however, further diagnostic tests need to be carried out to confirm seropositive cases.

Prevalence of Helicobacter pylori Infection and Diagnostic Methods in the Middle East and North Africa Region

Background and Objectives:Helicobacter pylori (H. pylori) infection is common worldwide and may cause gastroduodenal complications, including cancer. In this review, we examine the prevalence and distribution of various H. pylori genotypes and the risk factors for H. pylori infection, particularly in the Middle East and North Africa (MENA) region. We also introduce different global screening methods and guidelines and compare them to those currently in use in the MENA region. Materials and Methods: We searched the Google Scholar, PubMed, and Saudi Digital Library (SDL) databases for clinical trials and articles published in English. The data collection was mainly focused on MENA countries. However, for H. pylori genotypes and diagnostic methods, studies conducted in other regions or reporting global practices and guidelines were also included to allow a comparison with those in the MENA region. We also included studies examining the prevalence of H. pylori infection in healthy participants. Results:H. pylori infection is highly prevalent in the MENA region, mainly because of the accumulation of risk factors in developing countries. Herein, we highlight a lack of good quality studies on the prevalence of various H. pylori genotypes in the MENA region as well as a need for standard diagnostic methods and screening guidelines. Due to the complications associated with H. pylori, we recommend routine screening for H. pylori infection in all gastroenterology patients admitted in the MENA region. Conclusion: Concerted effort will first be required to validate affordable, non-invasive, and accurate diagnostic methods and to establish local guidelines with adapted cut-off values for the interpretation of the test results.

Efficacy and tolerability of fourteen-day sequential quadruple regimen: pantoprazole, bismuth, amoxicillin, metronidazole and or furazolidone as first-line therapy for eradication of Helicobacter pylori: a randomized, double-blind clinical trial

The optimal pharmacological regimen for eradication of Helicobacter pylori (H. pylori) has been investigated for many years. This study aimed to evaluate the efficacy and tolerability of bismuth-based quadruple therapy (B-QT) and a modified sequential therapy (ST) regimens in eradication of H. pylori. A randomized, double-blind trial was conducted on 344 patients. Patients with H. pylori infection and without a history of previous treatment were randomized to receive 14-day B-QT (bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg, and clarithromycin 500 mg twice daily) or 14-day ST (bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg, and metronidazole 500 mg twice a day for seven days followed by bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg, and furazolidone 100 mg twice a day for additional seven days). Drug adverse effects were assessed during the study. H. pylori eradication was determined eight weeks after the end of treatment using ¹⁴C-urea breath test. Based on per-protocol and intention-to-treat, the eradication rate was significantly higher (p<0.05) in the B-QT regimen 91.9 % (95 % CI; 88.1-94.0) and 90.2 % (95 % CI; 86.3-92.9), respectively compared to the ST regimen 80.8 % (95 % CI; 76.6-84.9) and 78.1 % (95 % CI; 73.7-82.4), respectively. The severity of vomiting and loss of appetite were significantly higher in ST regimen (p<0.05). The B-QT regimen was more effective and safer than the ST regimen. Conclusively, it is suggested to assess the efficacy and safety of this regimen in longer studies, larger population, and in other communities.

Association between VEGF-634G>C Gene Polymorphism with Gastric Premalignant Lesions and Serum VEGF Levels in Helicobacter pylori Gastritis Patients

AIM:

To evaluate the association between VEGF-634G>C gene polymorphism with premalignant gastric lesions as well as the level of VEGF.

METHODS:

This cross-sectional study included patients with H. pylori gastritis at Haji Adam Malik General Hospital, Permata Bunda General Hospital, and Universitas Sumatera Utara Hospital, Medan, Indonesia. Detection of H. pylori infection was made using positive results of ¹⁴C-UBT, rapid urease test, and/or immunohistochemistry. Gastric premalignant lesion diagnosis was made when one or more of the following were present: chronic atrophic gastritis, intestinal metaplasia, or dysplasia. Real-time polymerase chain reaction (RT-PCR) was used to examine VEGF-634G>C gene polymorphism. Additionally, serum samples of patients with H. pylori gastritis were obtained to determine the level of circulating VEGF. Data were analysed using SPSS version 22.

RESULTS:

A total number of 87 patients with H. pylori gastritis were included in this study. Of all participants, 26 patients (29.9%) showed gastric premalignancy. There was a significant association between GG+GC genotype of VEGF-634G>C and gastric premalignant lesions (P = 0.003; OR (CI 95%) = 6.07 (1.88-41.71)). VEGF-634 G>C polymorphism also showed an association with VEGF serum levels (P = 0.005). Patients with the GG+GC genotype would be at risk of 3.16 times to have high VEGF levels compared to CC genotypes.

CONCLUSION:

VEGF-634G>C polymorphism, in particular, GG+GC genotype was associated with an increased risk of gastric premalignant transformation as well as having high VEGF levels in patients with H.pylori gastritis.

Helicobacter pylori infection in dyspeptic patients in an industrial belt of India

The present study is done to study different aspects of Helicobacter pylori (H. pylori) such as its prevalence, association with upper gastrointestinal pathology, diagnosis and treatment outcome. Gastric antral biopsy and serology for H. pylori was done for all dyspeptic patients. Histopathology, gram stain and biopsy urease test was done from the gastric biopsy specimen. The prevalence of H. pylori infection was 58.8%. The sensitivity, specificity, positive and negative predictive value for histopathology was 96.9%, 100%, 100% and 95.8%, respectively; for biopsy urease test 80.4%, 100%, 100% and 78.2%, respectively; for gram stain 85.6%, 97.1%, 97.6% and 82.5%, respectively, and for serology 94.8%, 77.9%, 86% and 91.4%, respectively. Mostly peptic ulcer and duodenitis cases followed by chronic active gastritis were associated with H. pylori infection. Repeat biopsy revealed eradication of H. pylori in 90.7% cases. In dyspeptic patients, endoscopic biopsy not only detects H. pylori infection, but also reveals different gastric pathologies.

Seven-day quintuple regimen as a rescue therapy for Helicobacter pylori eradication

AIM: To determine the efficacy of two quintuple regimens for eradication of Helicobacter pylori (H. pylori) in patients who failed previous therapies.

METHODS: This prospective, open-label, randomized controlled trial was a phase II study conducted from April 2011 to March 2012 at the Gastrointestinal and Liver Diseases Research Center in Rasht, Iran. A total of 208 patients with dyspepsia who failed previous H. pylori eradication with a ten-day quadruple therapy were enrolled. A random block method was used to assign patients to one of two treatment groups. Patients in the first group were treated with 240 mg bismuth subcitrate, 20 mg omeprazole, 1000 mg amoxicillin, 500 mg clarithromycin and 500 mg tinidazole (BOACT group). Patients in the second group received a regimen containing 240 mg bismuth subcitrate, 20 mg omeprazole, 500 mg tetracycline, 500 mg metronidazole and 200 mg ofloxacin (BOTMO group). Both regimens were given twice daily for a duration of seven days. The eradication was confirmed by a ¹⁴C urea breath test 12 wk after completion of therapy. Patient compliance and drug side effects were evaluated at the end of the treatment period. The success rates were calculated by intention-to-treat and per-protocol analyses.

RESULTS: A total of 205 patients completed the course of treatment, with three patients excluded due to drug intolerance. The mean age of patients did not differ between the BOACT and BOTMO groups (41.6 ± 12.2 years vs 39.6 ± 11.8 years), and no significant differences were found between the two groups in terms of age, sex, smoking habits or the initial eradication regimen. The intention-to-treat and per-protocol eradication rates were significantly higher in the BOTMO group (86.5%, 95%CI: 0.85-0.87 and 86.7%, 95%CI: 0.80-0.89, respectively) compared with the BOACT group (75.5%, 95%CI: 0.73-0.76 and 76%, 95%CI: 0.69-0.80, respectively) (P < 0.05). Univariate analyses for both groups did not show any association of sex, smoking and initial therapeutic regimen with eradiation rate (P > 0.05 for all). Significantly more patients experienced side effects in the BOACT group compared to the BOTMO group (77.4% vs 36.6%, P < 0.01). This difference was exemplified by increases in headache and taste disturbance (P < 0.05).

CONCLUSION: Quintuple therapy with a BOTMO regimen is an alternative second-line rescue therapy for Iranian patients with failed first-line eradication treatment of H. pylori.

Unique features and risk factors of Helicobacter pylori infection at the main children's intermediate school in Rabigh, Saudi Arabia

BACKGROUND

This study was conducted to determine characters and risk factors of Helicobacter pylori infection and its relationship with recurrent abdominal pain and other gastrointestinal symptoms at the main children's intermediate school in Rabigh, Saudi Arabia.

METHODS

A cross-sectional study was conducted at a boys' intermediate school. A questionnaire for the gastrointestinal (GI) symptoms and relevant personal and socioeconomic risk factors related to H. pylori infection was distributed followed by H. pylori IgG antibody assay and 14C urea breath test to detect active infection.

RESULTS

H. pylori was diagnosed by positive urea breath test in 51.5 % of students. H. pylori infection was symptomatic with at least one upper GI symptom in 89.7 % of infected students which was higher than symptomatic cases reported in any other study. H. pylori-infected students had significantly more association with the presence of any upper GI symptom (p < 0.001), recurrent abdominal pain (p < 0.001), anorexia (p < 0.001), nausea (p < 0.026), family history of peptic disease (p < 0.001), drinking desalinated municipal water (p < 0.001), lower income (p = 0.02), and eating outside home (p = 0.003) than uninfected students. Logistic regression analysis showed that the most significant predictors of H. pylori infection were presence of any upper GI symptom (OR 5.3, 95 % CI 2.32-15.71), family history of peptic disease (OR 2.2, 95 % CI 1.11-3.9), and drinking desalinated municipal water (OR 2.1, 95 % CI 1.09-3.2).

CONCLUSIONS

This study presented unique features and risk factors of H. pylori infection in 12-15-year-old Saudi boys in Rabigh, and mainly supported the role of H. pylori in causing recurrent abdominal pain.

Comparison of encapsulated versus nonencapsulated (14) C-urea breath test for the detection of Helicobacter pylori infection: a scintigraphy study

BACKGROUND AND AIMS

(14) C-urea breath test ((14) C-UBT) is considered as "gold standard" for detection of active gastric H. pylori infection. However, till date no comparative study using encapsulated and non-encapsulated (14) C-UBT protocols has been conducted in same subjects in identical conditions. We monitored gastric fate of capsule containing (14) C-urea with real time display and compared sensitivities of these protocols at different time points of breath collection.

METHODS

Non-encapsulated (14) C-UBT was performed using 74 kBq of (14) C-urea in 100 dyspeptic patients by collecting breath samples at 10, 15 and 20 minutes. Thereafter, within 2 days a gelatin capsule containing (14) C-urea along with 6.0 MBq of (99m) Tc-diethylene triamine penta-acetic acid was administered to each patient for real time display of capsule movement and its fate in gastrointestinal tract by gamma camera. Simultaneously, breath samples were collected for (14) CO2 measurement during image acquisition.

RESULTS

Employing non-encapsulated (14) C-UBT, 74 out of 100 dyspeptic patients were found to be H. pylori positive. Discordant (14) C-UBT results were obtained in 4/74 (5.4%) cases using these two protocols. By employing encapsulated and nonencapsulated (14) C-UBT protocols, sensitivities of (14) C-UBT were found to be 90.5 versus 98.6% at 10 and 91.8 versus 97.2% at 15 minutes respectively; while these were 94.6 versus 100, 90.7 versus 98.6 and 83.7 versus 93.2% considering any one, two or all three positive values respectively.

CONCLUSIONS

Incomplete/non-resolution of (14) C-urea capsule in stomach during the phase of breath collections appears to decrease sensitivity of encapsulated (14) C-UBT as compared to nonencapsulated protocol for detection of H. pylori infection.

Bacterial urease and its role in long-lasting human diseases

Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. The presence of ureolytic activity is an important marker of a number of bacterial infections. Urease is also an immunogenic protein and is recognized by antibodies present in human sera. The presence of such antibodies is connected with progress of several long-lasting diseases, like rheumatoid arthritis, atherosclerosis or urinary tract infections. In bacterial ureases, motives with a sequence and/or structure similar to human proteins may occur. This phenomenon, known as molecular mimicry, leads to the appearance of autoantibodies, which take part in host molecules destruction. Detection of antibodies-binding motives (epitopes) in bacterial proteins is a complex process. However, organic chemistry tools, such as synthetic peptide libraries, are helpful in both, epitope mapping as well as in serologic investigations.

In this review, we present a synthetic report on a molecular organization of bacterial ureases - genetic as well as structural. We characterize methods used in detecting urease and ureolytic activity, including techniques applied in disease diagnostic processes and in chemical synthesis of urease epitopes. The review also provides a summary of knowledge about a toxic effect of bacterial ureases on human body and about occurrence of anti-urease antibodies in long-lasting diseases.

Association of Helicobacter pylori infection with the Lewis and ABO blood groups in dyspeptic patients

Background:

Helicobacter pylori infection is a basic risk factor for chronic gastritis, and gastric carcinoma. Based on some studies, the reason is binding of H. pylori to H and Le^b antigens in gastric mucosa. However, some other findings have not determined any association between the infection and these antigens. Because of this controversy and the fact that H. pylori infection and gastric adenocarcinoma are common diseases in Iran, the assessment of the association of H. pylori infection with these blood groups could be valuable.

Materials and Methods:

In a cross sectional study on 135 adult dyspeptic patients in Mashhad, Iran, from 2009 to 2010, H. pylori infection was evaluated by using the Heliprobe ¹⁴C-urea breath test and the ABO and Lewis blood group antigens were determined by the tube method. Association between the Lewis and ABO phenotypes with H. pylori infection were analysed by Fisher's exact test. A P ≤ 0.05 was considered to be significant.

Results:

68 (50.4%) patients were positive for H. pylori infection. The frequencies of the ABO, Lewis and secretion phenotypes were not significant in the infected and non-infected patients. We also did not find a significant association between Le^a and Le^b antigens and this infection.

Conclusion:

We could not establish a significant association between the Lewis, ABO and secretion phenotypes with H. pylori infection. Diversity of sequences of blood group antigen b-binding adhesion (babA gene) of H. pylori may be a reason why our findings are different from other studies in other geographic areas.

Effect of gastric acidification on the (14)C-UBT HELIPROBE(®) accuracy during Pantoprazole treatment in Helicobacter pylori positive patients

The aim of this study was to evaluate the influence of using Citric Acid on false negative rates induced by PPIs during (14)C-UBT in dyspeptic patients with H. pylori infection. In a crossover randomized controlled clinical trial, one hundred dyspeptic patients (46 females and 54 males) with determined H. pylori infection who referred to gastrointestinal Outpatient Clinic of Razi Hospital-Rasht, Iran. All the patients underwent a (14)C-UBT HELIPROBE(®) baseline test and the positive ones entered the second phase. They were divided randomly to two groups and started PPIs treatment by Pantoprazole (20 mg/daily Pantozol(®) Nycomed Company) and underwent two other UBTs in days 12-13 and 14-15 with and without 4 grams Citric Acid. In group I who underwent UBT with Citric Acid in days 12-13 (UBT2) and UBT without Citric Acid in days 14-15 (UBT3), there was no significant difference between the UBT results with and without Citric Acid (P≥0.05). In group II who underwent UBT without Citric Acid in days 12-13 and UBT with Citric Acid in days 14-15, the false negative rates were not significantly different between UBT with and without Citric Acid (P≥0.05). In both groups the results of UBT without Citric Acid after Pantoprazole consumption didn't change significantly compared to the baseline UBT. Also the difference between the false negative rates of baseline UBT and UBT without citric acid was not significant (P>0.05). These results suggest that acidification of gastric environment during (14)C-UBT cannot prevent false negative results and do not increase the accuracy of the test in patients taking PPIs.