Diagnostic performance of urea breath test, rapid urea test, and histology for Helicobacter pylori infection in patients with partial gastrectomy: a meta-analysis

Tracking the Helicobacter pylori Epidemic in Adults and Children in China

BACKGROUND

The Helicobacter pylori epidemic in China accounts for up to a third of gastric cancers worldwide. We aim to monitor the temporal and spatial dynamics of H. pylori infection in both adults and children across China.

MATERIALS AND METHODS

We developed a surveillance system consisting of a data collection component that harnessed survey reports in natural populations and an analysis component that accounted for the differences in survey time and location, population age structure, and H. pylori detection method. System outputs were estimates of the prevalence of H. pylori in adults and children (aged ≤ 14 years) presented at three hierarchical levels (regional, provincial, and prefectural).

RESULTS

The overall prevalence of H. pylori infection declined sharply in adults (63.3%, 52.5%, 43.4%, and 38.7%) and less sharply in children (23.1%, 26.1%, 16.0%, and 15.7%) in 1983-1999, 2000-2009, 2010-2014, and 2015-2019, respectively. The changes were asynchronous across regions, with the most marked declines in the Northwest, the Hong Kong-Macao-Taiwan region, and the East. We estimated that 457.6 million adults and 44.5 million children have been infected with H. pylori, with cross-province disparities in prevalence ranging from 24.3% to 69.3% among adults and 2.9% to 46.3% among children. In general, the risk level of gastric cancer increased as the prevalence of H. pylori increased. The correlation was statistically significant for both adult men (Spearman coefficient of correlation: 0.393, p = 0.0146) and women (0.470, p = 0.0029).

CONCLUSIONS

The tracking system would be important for the continuous and stratified tracking of the Helicobacter pylori epidemic across China and can be used to furnish an evidence base for the formulation of tailored prevention strategies.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Helicobacter pylori Eradication in Patients Undergoing Gastrectomy: Diagnosis and Therapy

The role of <i>Helicobacter pylori</i> (<i>H. pylori</i>) eradication in patients undergoing gastrectomy for gastric cancer is unclear. Although European and Asian guidelines strongly recommend <i>H. pylori</i> eradication in patients who undergo endoscopic resection for early gastric cancer, these guidelines do not specify the tests useful for diagnosing <i>H. pylori</i> infection, the optimal timing and appropriate eradication regimens, and follow-up strategies in patients undergoing gastrectomy for gastric cancer. This review aims to update the guidelines for the diagnosis and management of <i>H. pylori</i> infection in patients undergoing gastrectomy for gastric cancer. We have focused on the following issues: 1) diagnostic tests for <i>H. pylori</i> infection in the remnant stomach, 2) optimal timing and regimen for <i>H. pylori</i> eradication, and 3) role of <i>H. pylori</i> eradication in reducing the risk of metachronous gastric cancer in the remnant stomach.

Association between Active Helicobacter pylori Infection and Glaucoma: A Systematic Review and Meta-Analysis

Background: Glaucoma is the second most common cause of blindness worldwide affecting almost 70 million individuals. Helicobacter pylori (H. pylori) is a widespread pathogen with systematic pathogenicity. This meta-analysis aimed to estimate the contradictory data regarding a potential association between active H. pylori infection and glaucoma. Materials and Methods: A research in MEDLINE/PubMed and Google Scholar was conducted and original studies investigating the relationship between H. pylori infection and glaucoma were included. Analysis was performed with random effects model. The main outcome was the odds ratio (OR) with 95% confidence intervals (CI) of H. pylori infection as a risk factor for glaucoma. A parallel analysis studied the role of active infection as indicated by histology and the titer of anti-H. pylori antibodies. For the anti-H. pylori antibody titers, weighted mean differences (WMD) were estimated between patients and controls. Results: Fifteen studies were included, with 2664 participants (872 patients with glaucoma and 1792 controls), divided into primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) and pseudo-exfoliation glaucoma (PEG). The association between H. pylori infection and overall glaucoma was significant (OR = 2.08, CI 95% 1.48–2.93) with moderate heterogeneity (I² = 61.54%). After stratification by glaucoma subtype, heterogeneity was eliminated in the NTG subgroup. Studies with healthy controls, and controls with anemia yielded very low or no heterogeneity, respectively. Gastric biopsy to document active H. pylori infection yielded the highest OR (5.4, CI: 3.17–9.2, p < 0.001) and null heterogeneity. For anti-H. pylori antibody titers, there was a significant difference in WMD between patients and controls (WMD 15.98 IU/mL; 95% CI: 4.09–27.87; p = 0.008); values were greater in glaucoma patients, with high heterogeneity (I²: 93.8%). Meta-regression analysis showed that mean age had a significant impact on glaucoma (p = 0.037). Conclusions: Active H. pylori infection may be associated with glaucoma with null heterogeneity, as, beyond histology, quantified by anti-H. pylori titers and increases with age.

Helicobacter pylori as a risk factor for gastric cancer: the evidence and primary prevention strategy

Russia is a country with a high prevalence of Helicobacter pylori (HP) infection, a high incidence of gastric cancer, and its late diagnosis. HР infection has been recognized as the leading manageable risk factor for gastric cancer. Accurate diagnostic tests must be used to identify and control the effectiveness of HP eradication, and effective schemes must be implemented for HP eradication. The aim of this article was to analyze the latest consensus documents, systematic reviews and meta-analyzes that reflected the role of HP as a risk factor for the development of gastric cancer, as well as measures for the risk reduction. We describe in detail the diagnostic methods for HP infection, provide data on their use in the Russian Federation, and analyze the efficacy of eradication regimens. In all HPinfected individuals, HP leads to chronic inflammation in the gastric mucosa and launches a precancerous cascade (Correa's cascade). The risk of gastric cancer increases with severe atrophy, intestinal metaplasia and dysplasia. Primary prevention of gastric cancer is most effective if the eradication is performed before atrophic gastritis develops. The available consensus documents underline the importance of HP infection identification by accurate diagnostics at this stage of chronic gastritis. In Russia, the primary HP diagnosis is based on histology (37.7%), rapid urease test (29.2%), and serology (29.7%). HP stool antigen test (31.3%), 13C-urea breath test (23.4%) and the histological method (23.3%) are most often used to control eradication. Currently, the first line of eradication therapy is recommended as triple therapy with clarithromycin prescribed for 14 days. It is recommended to use double dose of proton pump inhibitors and bismuth to increase the effectiveness of this scheme. A 14-days triple regimen enhanced by bismuth has been recommended as the first-line therapy in the Russian Federation.

¹³C-Urea Breath Test Accuracy for <i>Helicobacter pylori</i> Infection in the Asian Population: A Meta-Analysis

Background:

Helicobacter pylori (H. pylori) infection is known to be associated with peptic ulcer and gastric cancer. Detection of H. pylori infection is a significant part of peptic ulcer and gastric cancer prevention and management. ¹³C-urea breath test (UBT) provides a good option for the pathogen detection due to its accuracy and safety.

Objective:

This review aims to evaluate the ¹³C-UBT diagnostic accuracy studies conducted among Asian population and validate its use for the Asian population.

Methods:

Original articles were systematically searched in PubMed, Scopus, and Google Scholar using the PICOS strategy by applying relevant keywords. Only studies published in English and conducted in Asia were included. Our search returned 276 articles. After assessment, 11 articles which answered our research question and met the criteria set for systematic review and meta-analysis were accepted. A total of 15 study protocols were extracted from the 11 accepted articles.

Findings:

Majority of the studies were conducted in Hong Kong (six), followed by Taiwan (five), Japan (two), and one each in Singapore and Israel. All studies had used histology as part of its gold standard of reference. All but one study was performed on adult populations. The summary estimate for sensitivity was 97% (95% CI: 96, 98%), and specificity was 96% (95% CI: 95, 97%), with significant heterogeneity between studies. Adjusting for the dose (50 mg) and breath sample collection time (20 minutes) had improved both accuracy estimates and significantly reduced heterogeneity.

Conclusion:

This review supports the test-and-treat strategy for H. pylori infection management. Prevalence and cost-effectiveness studies are mandatory for health authorities to adopt this strategy into national policy.

Diagnostic methods for Helicobacter pylori infection: ideals, options, and limitations

Helicobacter pylori (H. pylori) resides in the stomach, colonizes gastric epithelium, and causes several digestive system diseases. Several diagnostic methods utilizing invasive or non-invasive techniques with varying levels of sensitivity and specificity are developed to detect H. pylori infection. Selection of one or more diagnostic tests will depend on the clinical conditions, the experience of the clinician, cost, sensitivity, and specificity. Invasive methods require endoscopy with biopsies of gastric tissues for the histology, culture, and rapid urease test. Among non-invasive tests, urea breath test and fecal antigen tests are a quick diagnostic procedure with comparable accuracy to biopsy-based techniques and are methods of choice in the test and treatment setting. Other techniques such as serological methods to detect immunoglobulin G antibodies to H. pylori can show high accuracy as other non-invasive and invasive biopsies, but do not differentiate between current or past H. pylori infections. Polymerase chain reaction (PCR) is an emerging option that can be categorized as invasive and non-invasive tests. PCR method is beneficial to detect H. pylori from gastric biopsies without the need for the cultures. There is no other chronic gastrointestinal infection such as H. pylori with a set of comparable diagnostic methodologies. Despite the availability of multiple diagnostic methods, it remains unclear on the choice of any one method as the gold standard for detecting H. pylori infection, especially in epidemiological studies. In this work, we review the principal diagnostic methods used to detect H. pylori infection and their advantages and disadvantages, and applications in clinical practice.

[Diagnosis of Helicobacter pylori Infection]

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is mandatory for the effective management of many gastroduodenal diseases. Currently, various diagnostic methods are available for detecting these infections, and the choice of method should take into account the clinical condition, accessibility, advantage, disadvantage, as well as cost-effectiveness. The diagnostic methods are divided into invasive (endoscopic-based) and non-invasive methods. Non-invasive methods included urea breath test, stool antigen test, serology, and molecular methods. Invasive methods included endoscopic imaging, rapid urease test, histology, culture, and molecular methods. In this article, we provide a review of the currently available options and recent advances of various diagnostic methods.

Comparison of tests for detecting Helicobacter pylori in gastric biopsy

AIM

To figure out a method to detect Helicobacter pylori (H. pylori) infection that is of high sensitivity and specificity as well as clinically easy-handling by comparing four common H. pylori detection methods.

METHODS

Four hundred and ninety gastric mucosa biopsies were tested separately by the rapid urease test (RUT), fluorescence quantitative polymerase chain reaction (qPCR), methylene blue staining, and immunohis-tochemistry (IHC). Positive rates obtained by the different methods were analyzed by the χ² test.

RESULTS

The positive rates of H. pylori obtained by RUT, qPCR, methylene blue staining, and IHC were 18.98%, 63.88%, 32.04%, and 38.16%, respectively, which were statistically different (P < 0.005).

CONCLUSION

IHC provides a visual scene for observers, and there is a sharp contrast for IHC images between H. pylori infected and surrounding areas. This feature can facilitate researchers to obtain morphological information with potential clinical value. Furthermore, IHC protocols are friendly to instruments and operators. Hence, we recommend that IHC be used to detect H. pylori in gastric biopsies for diagnosing H. pylori infection and determining H. pylori treatment.

Fifth Chinese National Consensus Report on the management of Helicobacter pylori infection

BACKGROUND

Since the 'Fourth Chinese National Consensus Report on the management of H. pylori infection' was published in 2012, three important consensuses (Kyoto global consensus report on H. pylori gastritis, The Toronto Consensus for the Treatment of H. pylori Infection in Adults and Management of H. pylori infection-the Maastricht V/Florence Consensus Report) have been published regarding the management of H. pylori infection.

MATERIALS AND METHODS

A Delphi method was adopted to develop the consensus of relevant 'statements'. First, the established 'statements' were sent to experts via email. Second, after undergoing two rounds of consultation, the initial statements were discussed face to face and revised in the conference item by item on 16 December 2016. Finally, 21 core members of conferees participated in the final vote of statements. Voting for each statement was performed using an electronic system with levels of agreements shown on the screen in real time.

RESULTS

Consensus contents contained a total of 48 "statements" and related 6 parts, including indications for H. pylori eradication, diagnosis, treatment, H. pylori and gastric cancer, H. pylori infection in special populations, H. pylori and gastrointestinal microbiota.

CONCLUSIONS

Recommendations are provided on the basis of the best available evidence.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Efficacy of a quadruple therapy regimen for Helicobacter pylori eradication after partial gastrectomy

We aimed to evaluate the effectiveness and safety of bismuth-containing quadruple therapy plus postural change after dosing for Helicobacter pylori eradication in gastrectomized patients. We compared 76 gastric stump patients with H. pylori infection (GS group) with 50 non-gastrectomized H. pylori-positive patients who met the treatment indication (controls). The GS group was divided into GS group 1 and GS group 2. All groups were administered bismuth potassium citrate (220 mg), esomeprazole (20 mg), amoxicillin (1.0 g), and furazolidone (100 mg) twice daily for 14 days. GS group 1 maintained a left lateral horizontal position for 30 min after dosing. H. pylori was detected using rapid urease testing and histologic examination of gastric mucosa before and 3 months after therapy. Mucosal histologic manifestations were evaluated using visual analog scales of the updated Sydney System. GS group 1 had a higher prevalence of eradication than the GS group 2 (intention-to-treat [ITT]: P=0.025; per-protocol [PP]: P=0.030), and the control group had a similar prevalence. GS group 2 had a lower prevalence of eradication than controls (ITT: P=0.006; PP: P=0.626). Scores for chronic inflammation and activity declined significantly (P<0.001) 3 months after treatment, whereas those for atrophy and intestinal metaplasia showed no significant change. Prevalence of adverse reactions was similar among groups during therapy (P=0.939). A bismuth-containing quadruple therapy regimen plus postural change after dosing appears to be a relatively safe, effective, economical, and practical method for H. pylori eradication in gastrectomized patients.

Effect of posture on 13C-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 mL 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 breath samples 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.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Isolation and diagnosis of Helicobacter pylori by a new method: Microcapillary culture

AIM: To investigate the performance of the microcapillary culture method (MCM) in Helicobacter pylori (H. pylori) isolation and diagnosis.

METHODS: Microcapillary culture (MC), classical culture (CC), rapid urease (CLO) test, and histopathologic examination (HE) were performed with biopsy samples. Homogenized biopsy samples were loaded into capillary tubes and incubated for 48 h at 37 °C without providing a microaerophilic environment. Additionally, three or four loops of the homogenized sample were inoculated in a ready-to-use selective medium (Becton Dickinson, Helicobacter Agar, Modified) specific for the isolation of H. pylori and incubated at 37 °C in a microaerophilic atmosphere provided by CampyGen (Becton Dickinson, GasPack). Bacteria reproducing in microcapillary tubes were evaluated in an inverted microscope and also were evaluated after performing a CC with the content. Results obtained by CC, CLO test, and HE were compared with those of MC. The diagnostic performances of the methods used in this study were evaluated for specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and CI.

RESULTS: H. pylori was found positive by CLO test + HE and/or CC culture in 26 patient antrum and corpus biopsy samples. In 25 (25/26) patient biopsy samples, H. pylori was isolated by MCM, whereas in only 14 (14/26) patient biopsy samples, H. pylori was isolated by CC. CLO test and HE were found positive in 17 (17/26) patient biopsy samples. Comparing the results of the isolation of H. pylori by MCM, CC, CLO test, and HE, the sensitivity of the MCM was found as 96%, the specificity as 80%, the PPV as 83%, the NPV as 95%, and the 95%CI as 0.76 (χ² = 31.51, P < 0.01) whereas the sensitivity of the CC was found as 54% (χ² = 19.15, P < 0.01), and the sensitivity of the CLO test and HE were found as 65% (χ² = 25.26, P < 0.01).

CONCLUSION: This new microcapillary cultivation method for H. pylori has high diagnostic sensitivity compared with CC, HE, and CLO tests.

Diagnosis of Helicobacter pylori using the rapid urease test

Helicobacter pylori (H. pylori) is a major human pathogen which causes progressive gastroduodenal damage. Guidelines recommend that, unless there are compelling reasons to delay, treatment is indicated for all patients in whom the infection is diagnosed. The rapid urease test (RUT) is a popular diagnostic test in that it is a rapid, cheap and simple test that detects the presence of urease in or on the gastric mucosa. The sensitivity and specificity are generally high and many versions have been approved for use in humans. Best results are obtained if biopsies are obtained from both the antrum and corpus. The tissue sample embedded in the RUT gel can also be utilized for other tests such as for molecular based tests of microbial susceptibility or for host factors. False-positive results are rare if the RUT contains an antibacterial agent to prevent growth of urease-containing contaminants and the tests are discarded at 24 hours. The use of antimicrobial drugs and proton pump inhibitors as well as the presence of intestinal metaplasia may result in false-negative results. A negative test should not be used as the criteria for cure or in cases where accuracy is important for patient management such as in upper gastrointestinal bleeding. Interpretation of the test should take into account the pretest probability and the prevalence of H. pylori in the population. The test can also be used to provide an informal assessment of the accuracy of the histopathology result and discrepancies should prompt a review of the histopathology and discussions with the pathologist.

Methylated TIMP-3 DNA in body fluids is an independent prognostic factor for gastric cancer

CONTEXT

Fluid methylated DNA may be a suitable biomarker for cancer patients.

OBJECTIVE

To investigate whether circulating methylated tissue inhibitor of metalloproteinase 3 (TIMP-3) DNA in body fluids is a useful prognostic biomarker in gastric cancer (GC).

DESIGN

TIMP-3 methylation was detected by real-time methylation-specific polymerase chain reaction in tumor tissues, paired preoperative peritoneal washes (PPWs), and paired serum samples from 92 GC patients.

RESULTS

The frequency of TIMP-3 methylation was significantly elevated in GC tissues (63.04%; 58 of 92) compared with that in paired adjacent normal tissue (4.3%; 4 of 92) (P < .001). TIMP-3 methylation correlated closely with peritoneal metastasis and TNM stage (all P < .001). The frequency of TIMP-3 methylation in preoperative peritoneal washes and serum samples was 53.3% (49 of 92) and 58.7% (54 of 92), respectively. The Aζ values of the receiver operator characteristic curve for methylated TIMP-3 were 0.966 and 0.922 for serum and preoperative peritoneal washes, respectively, compared with those in GC tissues. The patients with elevated methylated TIMP-3 levels in body fluids had poorer disease-free survival rates than those without (all P < .001). Cox regression analysis showed that detection of methylated TIMP-3 DNA in body fluids was an independent risk factor for GC patients, with a remarkable decrease in disease-free survival 30 months after surgical resection of the gastric tumor.

CONCLUSION

Presence of methylated TIMP-3 DNA in body fluids is a useful biomarker for predicting the progression and prognosis of GC patients.

Evaluation of Exalenz Bioscience's BreathID for Helicobacter pylori detection

Carbon-labeled urea breath tests, which have high sensitivity and specificity, are the preferred method used in epidemiological studies, screening dyspeptic patients and assessing eradication or recurrence of Helicobacter pylori infection. The principle of the (13)C-urea breath test relies upon the ability of the H. pylori urease to hydrolyze the orally administered (13)C-urea. The BreathID (Exalenz Bioscience Inc., Union, NJ, USA) provides a competitive solution for breath testing, including unique features such as automatic continuous breath collection and analysis. This is an unattended convenient test, with no human error as the correct part of the breath is collected and patients' assistance is not required. The test results are available in real time at the point of care and enable shortened breath testing procedures. Additionally, several studies showing expanded utility of the BreathID in pediatrics, after therapy and during proton pump inhibitors intake, further support the safety and performance of the BreathID in the diagnosis of H. pylori.

Management of Helicobacter pylori infection in Latin America: a Delphi technique-based consensus

AIM

To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature.

METHODS

Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria.

RESULTS

A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included: (1) when available, urea breath and stool antigen test (HpSA) should be used for non-invasive diagnosis; (2) detect and eradicate Helicobacter pylori (H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer; (3) further investigate implementation issues and health outcomes of H. pylori eradication for primary prevention of gastric cancer in high-risk populations; (4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment; (5) routinely assess eradication success post-treatment in clinical settings; and (6) select second- and third-line therapies according to antibiotic susceptibility testing.

CONCLUSION

These achievable steps toward better region-specific management can be expected to improve clinical health outcomes.

Helicobacter pylori infection - recent developments in diagnosis

Considering the recommended indications for Helicobacter pylori (H. pylori) eradication therapy and the broad spectrum of available diagnostic methods, a reliable diagnosis is mandatory both before and after eradication therapy. Only highly accurate tests should be used in clinical practice, and the sensitivity and specificity of an adequate test should exceed 90%. The choice of tests should take into account clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy and the availability of the tests. This review concerns some of the most recent developments in diagnostic methods of H. pylori infection, namely the contribution of novel endoscopic evaluation methodologies for the diagnosis of H. pylori infection, such as magnifying endoscopy techniques and chromoendoscopy. In addition, the diagnostic contribution of histology and the urea breath test was explored recently in specific clinical settings and patient groups. Recent studies recommend enhancing the number of biopsy fragments for the rapid urease test. Bacterial culture from the gastric biopsy is the gold standard technique, and is recommended for antibiotic susceptibility test. Serology is used for initial screening and the stool antigen test is particularly used when the urea breath test is not available, while molecular methods have gained attention mostly for detecting antibiotic resistance.

Circulating methylated MINT2 promoter DNA is a potential poor prognostic factor in gastric cancer

BACKGROUND AND AIM

Aberrant DNA methylation has been shown to be associated with the growth, development, metastasis, and prognosis of tumors. Methylated DNAs may be suitable biomarkers for cancer patients. Here, we investigated whether circulating methylated MINT2 DNAs represent a potential poor prognostic factor in gastric cancer (GC).

METHODS

MINT2 methylation was detected by real-time methylation-specific PCR in tumor tissues, pairing preoperative peritoneal lavage fluid (PPLF) and blood from 92 GC patients. The theory meaning and clinical practicality value of MINT2 methylation in different specimens were analyzed.

RESULTS

The methylation status of the MINT2 gene was found to be significantly higher in tumor tissues (44.6%, 41/92) than in adjacent normal tissues (3.3%, 3/92). No MINT2 methylation was found in healthy controls, and partial MINT2 methylation was observed in three (6.25%, 3/48) patients with chronic atrophic gastritis. The frequency of MINT2 methylation in pairing PPLF and blood samples from 92 GC patients was 40.2% (37/92) and 39.1% (36/92), respectively. Methylated MINT2 in tumor tissues, pairing PPLF, and blood samples were very approximate. Aberrant MINT2 methylation in tumor tissues and pairing PPLF or blood samples were closely related to peritoneal dissemination, tumor progression, and poor prognosis (all P < 0.0001).

CONCLUSIONS

Aberrant MINT2 methylation in PPLF/blood may predict peritoneal micrometastasis for GC patients, which is a potential poor prognostic factor in GC.

Management of Helicobacter pylori infection after gastric surgery

The Maastricht IV/Florence Consensus Report and the Second Asia-Pacific Consensus Guidelines strongly recommend eradication of Helicobacter pylori (H. pylori) in patients with previous gastric neoplasia who have undergone gastric surgery. However, the guidelines do not mention optimal timing, eradication regimens, diagnostic tools, and follow-up strategies for patients undergoing gastrectomy and do not indicate if eradication of H. pylori reduces the risk of marginal ulcer or stump cancer in the residual stomach after gastrectomy. The purpose of this review is to provide an update which may help physicians to properly manage H. pylori infection in patients who have undergone gastric surgery. This review focuses on (1) the microenvironment change in the stomach after gastrectomy; (2) the phenomenon of spontaneous clearance of H. pylori after gastrectomy; (3) the effects of H. pylori on gastric atrophy and intestinal metaplasia after gastrectomy; (4) incidence and clinical features of ulcers developing after gastrectomy; (5) does eradication of H. pylori reduce the risk of gastric stump cancer in the residual stomach? (6) does eradication of H. pylori reduce the risk of secondary metachronous gastric cancer in the residual stomach? and (7) optimal timing and regimens for H. pylori eradication, diagnostic tools and follow-up strategies for patients undergoing gastrectomy.

NEDD9 overexpression correlates with the progression and prognosis in gastric carcinoma

The aim of this study was to investigate neural precursor cell expressed developmentally down-regulated 9 (NEDD9) expression in human gastric carcinoma (GC) and to explore its clinic significance. NEDD9 expression was detected by immunohistochemistry in GC, their corresponding paracancerous histological normal tissues (PCHNTs), and gastric normal tissues. And this result was further confirmed at the protein and mRNA level by Western blotting and quantitative real-time PCR, respectively. The Kaplan-Meier method and log-rank test were employed to compare the overall survival between NEDD9 low-level expression group and NEDD9 high-level expression group. We ascertained frequently NEDD9 up-regulation in both protein and mRNA levels in GC tissues as compared to PCHNTs and normal controls. Immunohistochemical staining indicated that NEDD9 is higher expressed in GC tissues (102 out of 125, 81.8%) than that in PCHNTs (eight out of 42, 19.05%) and gastric normal tissues (one out of eight, 12.50%). NEDD9 expression levels were closely associated with poor differentiation (P=0.002), venous invasion (P=0.012), invasive depth (P<0.001), preset lymph node metastasis (P=0.023), distant metastasis (P=0.017), and high clinical stage (P=0.005). NEDD9 expression was positively correlated with clinical tumor node metastasis (TNM) stage that implied the more advanced clinical TNM stage corresponding to the higher expression level of NEDD9 (rs=0.467, P<0.001). And we also detected frequently NEDD9 up-regulation in both protein and mRNA levels in GC tissues as compared to PCHNTs. Kaplan-Meier survival analysis showed that high NEDD9 expression exhibited a significant correlation with poor prognosis for gastric cancer patients. Our data suggested that NEDD9 could be used as prognostic molecular marker to be applied in the clinical setting to diagnosis, evaluating patient's outcome (prognosis and recurrence) for GC patients.

Cost-effectiveness of screening and treating Helicobacter pylori for gastric cancer prevention

Gastric cancer is the second leading cause of cancer-related death worldwide. A meta-analysis of seven randomized controlled trials concluded that Helicobacter pylori eradication reduces gastric cancer incidence by 35%. Current consensus is that H. pylori screening and treatment is cost-effective only in high-risk populations. This paper provides an up-to-date overview of the evidence for cost-effectiveness of H. pylori screening and treatment in different population settings and risk levels for H. pylori infection. Ten unique cost-effectiveness or cost-utility analyses were identified. All found that screening for H. pylori to prevent gastric cancer in the general population costs less than $50,000 per LYG. This finding was robust for differences in H. pylori prevalence, gender and ethnicity. Based on limited evidence, re-treatment (for treatment failure), repeated screening, limiting screening and treatment to those with the CagA phenotype, or universal treatment, does not appear to be cost-effective. However, most included studies failed to consider both the broader benefits as well as the adverse effects of widespread use of antibiotics for H. pylori.

Diagnosis and epidemiology of Helicobacter pylori infection

A limited amount of new information was published in the field of diagnosis and epidemiology of Helicobacter pylori this last year. Besides some improvement in current tests, it is interesting to note the attempts to identify severe disease, for example gastric cancer, by breath analysis using nanomaterial-based sensors. In contrast, the predictive value for gastric cancer and atrophy of pepsinogen determinations was found inadequate. Prevalence studies of H. pylori infection have been carried out in adults and children around the world in the general population but also in specific communities. The usual risk factors were found. In addition, a Japanese study highlighted the role of grandmothers in the familial transmission of H. pylori. A study showed that the infection may not always readily establish itself in children, given the number of transient infections observed. It was also noted that after eradication, a first-year relapse is likely to be a recurrence of the previous infection, while later on it is probably a reinfection with a new strain.

Circulating Methylated XAF1 DNA Indicates Poor Prognosis for Gastric Cancer

BACKGROUND

Methylated DNA in fluids may be a suitable biomarker for cancer patients. XAF1 has been shown to be frequently down-regulated in human gastric cancer (GC). Here, we investigated if XAF1 methylation in GC could be a useful biomarker.

METHODS

Real-time RT-PCR was used to detect XAF1 mRNA expression; immunohistochemistry and western blot were used to examine XAF1 protein expression in GC tissues (n = 202) and their corresponding para-cancerous histological normal tissues (PCHNTs). Real-time methylation specific-PCR was used to investigate XAF1 promoter methylation in the same panel of GC tissues, their PCHNTs and sera.

RESULTS

We confirmed frequent XAF1 down-regulation in both mRNA and protein levels in GC tissues as compared to normal controls and PCHNTs. XAF1 hypermethylation was evidenced in 83.2% (168/202) of GC tissues and 27.2% (55/202) of PCHNTs, while no methylation was detected in the 88 normal controls. The methylation level in GC tissues was significantly higher than that in PCHNTs (p<0.05). The hypermethylation of XAF1 significantly correlated with the down-regulation of XAF1 in GC tissues in both mRNA and protein levels (p<0.001 each). Moreover, we detected high frequency of XAF1 methylation (69.8%, 141 out of 202) in the sera DNAs from the same patients, while the sera DNAs from 88 non-tumor controls were negative for XAF1 methylation. The XAF1 methylation in both GC tissues and in the sera could be a good biomarker for diagnosis of GC (AUC = 0.85 for tissue and AUC = 0.91 for sera) and significantly correlated with poorer prognosis (p<0.001). In addition, after-surgery negative-to-positive transition of XAF1 methylation in sera strongly associated with tumor recurrence.

CONCLUSIONS

1) Dysfunction of XAF1 is frequent and is regulated through XAF1 promoter hypermethylation; 2) Detection of circulating methylated XAF1 DNAs in the serum may be a useful biomarker in diagnosis, evaluating patient's outcome (prognosis and recurrence) for GC patients.

Predictive value of neutrophil infiltration as a marker of Helicobacter pylori infection

AIM: To evaluate the predictive value of neutrophil infiltration as a marker of Helicobacter pylori (H. pylori) infection.

METHODS: A total of 315 patients with dyspepsia symptoms who underwent upper gastrointestinal endoscopy were enrolled in this study. Biopsies were evaluated using the updated Sydney system. The medication history of all patients in the preceding 4 wk was recorded. The diagnosis of H. pylori infection was based on ¹³C-urea breath test at least 4 wk after withdrawal of antisecretory drugs, antibiotics and related drugs. For the patients with subtotal gastrectomy, the diagnosis of H. pylori infection was based on anti-H. pylori immunoglobulin G (IgG) antibody. Serum anti-H. pylori IgG antibody was measured by enzyme-linked immunosorbent assays (Biohit, Finland).

RESULTS: The sensitivity, specificity, positive predictive value and negative predictive value of neutrophil infiltration in the diagnosis of H. pylori infection were 92.3%, 83.5%, 77.4% and 94.7%, respectively. Neutrophil infiltration of gastric mucosa in the histological analysis was strongly associated with H. pylori infection (77.4% vs 5.3% in the neutrophil infiltration negative group, P = 0.000). Moderate neutrophil infiltration was more frequent in H. pylori infection when compared to mild infiltration (81.8% and 75%, respectively), but did not reach statistical significance. For those patients with negative rapid urease test, H. pylori was detected in 73.2% of patients with positive neutrophil infiltration on histology. In patients with subtotal gastrectomy, the diagnostic accuracy of neutrophil infiltration in H. pylori infection was 50%.

CONCLUSION: Neutrophil infiltration is closely associated with H. pylori and may be recognized as a sign of this infection.

Epidemiology and diagnosis of Helicobacter pylori infection

Medline, PubMed and the Cochrane databases were searched on epidemiology and diagnosis of Helicobacter pylori for the period of April 2011-March 2012. Several studies have shown that the prevalence of H. pylori infection is decreasing in adults and children in many countries. Various diagnostic tests are available, and most of them have high sensitivity and specificity. The Maastricht IV/Florence consensus report states that the urea breath test using (13)C urea remains the best test to diagnose H. pylori infection. Among the stool antigen tests, the ELISA monoclonal antibody test is recommended. All these tests were used, either as a single diagnostic test or in combination, to investigate H. pylori infection among different populations throughout the world. Of particular interest, current improvements in high-resolution endoscopic technologies enable increased diagnostic accuracy for the detection of H. pylori infection, but none of these techniques, at present, are specific enough for obtaining a real-time diagnosis of H. pylori infection.