Usefulness of a delayed test for the diagnosis of Helicobacter pylori infection in bleeding peptic ulcer

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.

A Nationwide Cohort Study Shows a Sex-Dependent Change in the Trend of Peptic Ulcer Bleeding Incidence in Korea between 2006 and 2015

Background/Aims

The incidence of peptic ulcer disease has decreased in past decades; however, the trends in peptic ulcer bleeding (PUB) are inconsistent among regions. This study aimed to investigate the trends in PUB incidence and the effect of risk factors on PUB in Korea.

Methods

The records of patients hospitalized with PUB from 2006 to 2015 were retrieved from the Korean National Health Insurance Service Database. Standardized incidences of PUB were calculated, and the clinical characteristics such as age, sex, Helicobacterpylori infection, drug exposure, comorbidities, and mortality were obtained.

Results

In total, 151,507 hospitalizations with PUB were identified. The overall annual hospitalization rate was 34.98 per 100,000 person-years. The incidence of PUB showed no significant change from 2006 to 2008 and decreased from 2008 to 2015, with an annual change of –2.7% (p<0.05); however, this change was only significant in men. The incidence of PUB was higher in men than in women between 40 and 70 years old and higher in women than in men older than 80 years. From 2006 to 2015, the H. pylori infection rate increased significantly in patients with PUB; however, there was no significant change in exposure to nonsteroidal anti-inflammatory drugs or other drugs that increase the risk of PUB.

Conclusions

Over the past decade, the incidence of PUB has decreased in a sex-specific manner. There has been a decreasing trend in the H. pylori infection rate and no change in exposure to drugs that increase the risk of PUB in Korea.

Droplet Digital PCR Detects Low-Density Infection in a Significant Proportion of Helicobacter Pylori-Negative Gastric Biopsies of Dyspeptic Patients

INTRODUCTION

Helicobacter pylori-infected individuals may present low-density infection, undetectable by conventional tests such as histology, rapid urease test, or urea breath test. Droplet digital polymerase chain reaction (ddPCR) is more sensitive than other polymerase chain reaction methods. We aimed to evaluate the ability of ddPCR to detect H. pylori infection in patients diagnosed as negative by conventional tests.

METHODS

Dyspeptic patients (n = 236) were tested for H. pylori by histology, urea breath test, and rapid urease test. Patients were classified as having 3 positive (n = 25, control group), 2 positive (n = 12), one positive (n = 41), or zero positive (n = 158) diagnostic tests. DNA was extracted from gastric biopsies. Triplicate ddPCR testing for each of the 16S rDNA, ureA, and vacA(s) genes was performed using a QX200 ddPCR system (Bio-Rad). A gene was considered positive when detected by at least 2 of 3 repeated ddPCRs. H. pylori positivity was defined as having 2 or more positive genes.

RESULTS

All the biopsies of the control patients were positive for all 3 16S rDNA, ureA, and vacA(s) genes. H. pylori infection was detected in 57 (36%), 22 (54%), and 9 (75%) patients with zero, 1, and 2 positive diagnostic tests, respectively. The density of infection was 5, 121, 599, and 3,133 copies of H. pylori genome equivalents for patients with zero, 1, and 2 of 3 positive test results and for the control group, respectively.

DISCUSSION

ddPCR detected low-density "occult" H. pylori infection in a significant proportion (36%) of patients diagnosed as negative by conventional methods. The number of conventional positive tests was related to the density of infection.

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION

ABSTRACT Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

[Optimal Operational Definition of Patient with Peptic Ulcer Bleeding for Big Data Analysis Using Combination of Clinical Characteristics in a Secondary General Hospital]

BACKGROUND/AIMS

Peptic ulcer bleeding (PUB) is the most common cause of upper gastrointestinal bleeding in Korea but there has been no research done using big data. This study evaluates the optimal operational definition (OD) for big data research by analyzing clinical characteristics of PUB.

METHODS

We reviewed the clinical characteristics of 92 patients with PUB confirmed on endoscopy in Wonkwang University Sanbon Hospital (January 2013 to December 2014). We calculated sensitivity and positive predictive value (PPV) to detect confirmed PUB patients using ODs developed by combining clinical features of patients with PUB.

RESULTS

The mean patient age was 63 years. Men had higher prevalence of PUB than women. Bleeding gastric ulcer was proportionately common in the age range of 40s to 60s in men, while a significantly higher rate of bleeding occurred in women older than 70s. The rate of drug-induced ulcer was 28.2%, whereas the prevalence of Helicobacter pylori was 47.8%. Among the hospitalized patients with diagnostic code of PUB, we ruled out patients with endoscopic removal of gastric adenoma or peritonitis, and selected patients who had been administered intravenous proton pump inhibitor. The sensitivity in this setting was 82.6%, and PPV was 88.4%.

CONCLUSIONS

PUB was more common in older patients, and there was a clear gender difference in gastric ulcer bleeding by age. With a proper OD using PUB diagnostic codes, we can identify true patients with sufficiently high sensitivity and PPV.

Dual-priming oligonucleotide-based multiplex PCR using tissue samples from the rapid urease test kit for the detection of Helicobacter pylori in bleeding peptic ulcers

BACKGROUND

In patients with peptic ulcer bleeding (PUB), diagnostic tests for Helicobacter pylori (H. pylori) infection have low sensitivity. The aim of our study was to investigate the diagnostic yield of dual-priming oligonucleotide-based multiplex (DPO)-PCR using tissue samples from the rapid urease test (RUT, CLO(®)test) kit in patients with PUB.

METHODS

We prospectively enrolled patients with PUB. During second-look endoscopy, gastric biopsy specimens for histology and RUT were obtained from a total of 170 patients. DPO-PCR tests were performed on tissue samples obtained from the CLO(®)test kit. If testing for H. pylori was negative, endoscopy with re-biopsy was performed 8 weeks after the bleeding episode.

RESULTS

H. pylori-associated bleeding was confirmed in 64.1% (109/170) of the patients. At the bleeding episode, the diagnostic sensitivities of RUT, histology, and DPO-PCR test were 47.7% (52/109), 71.6% (78/109) and 97.2% (106/109), respectively (p<0.01). The specificity of the DPO-PCR test was 91.8% (56/61). The positive predictive value (PPV) of the DPO-PCR test was 95.5% (106/111), and its negative predictive value (NPV) was 94.9% (56/59).

CONCLUSIONS

In patients with PUB, the DPO-PCR test could be a useful diagnostic tool for H. pylori infection. Particularly given a negative RUT result, subsequent DPO-PCR testing of tissue samples from the CLO(®)test kit could be of considerable benefit.

Management of NSAID-associated peptic ulcer disease

Non-steroidal anti-inflammatory drug (NSAID) use increases the risk of gastrointestinal complications such as ulcers or bleeding. The presence of factors like advanced age, history of peptic ulcer, Helicobacter pylori infection and the use of anticoagulants or antiplatelet agents increase this risk further. COX-2 inhibitors and antisecretory drugs, particularly proton pump inhibitors, help to minimize the risk of gastrointestinal complications in high-risk patients. This review presents a practical approach to the prevention and treatment of NSAID-associated peptic ulcer disease and examines the new advances in the rational use of NSAIDs.

Occult H. pylori infection partially explains 'false-positive' results of (13)C-urea breath test

BACKGROUND

In a previous study, UBiT-100 mg, (Otsuka, Spain), a commercial (13)C-urea breath test omitting citric acid pre-treatment, had a high rate of false-positive results; however, it is possible that UBiT detected low-density 'occult' infection missed by other routine reference tests. We aimed to validate previous results in a new cohort and to rule out the possibility that false-positive UBiT were due to an 'occult' infection missed by reference tests.

METHODS

Dyspeptic patients (n = 272) were prospectively enrolled and UBiT was performed, according to the manufacturer's recommendations. Helicobacter pylori infection was determined by combining culture, histology and rapid urease test results. We calculated UBiT sensitivity, specificity, positive and negative predictive values (with 95% CI). In addition, we evaluated 'occult' H. pylori infection using two previously-validated polymerase chain reaction (PCR) methods for urease A (UreA) and 16 S sequences in gastric biopsies. We included 44 patients with a false-positive UBiT, and two control groups of 25 patients each, that were positive and negative for all H. pylori tests.

RESULTS

UBiT showed a false-positive rate of 17%, with a specificity of 83%. All the positive controls and 12 of 44 patients (27%) with false-positive UBiT were positive for all two PCR tests; by contrast, none of our negative controls had two positive PCR tests.

CONCLUSIONS

UBiT suffers from a high rate of false-positive results and sub-optimal specificity, and the protocol skipping citric acid pre-treatment should be revised; however, low-density 'occult' H. pylori infection that was undetectable by conventional tests accounted for around 25% of the 'false-positive' results.

Diagnosis of Helicobacter pylori Infection in the Proton Pump Inhibitor Era

Proton pump inhibitors (PPI) are a major cause of false-negative Helicobacter pylori test results. Detecting PPI use and stopping it 2 weeks before testing is the preferred approach to improve the reliability of H pylori diagnostic tests. Immunoblot and molecular methods may be useful for the detection of H pylori infection in difficult cases. When conventional tests are negative and eradication is strongly indicated, empirical H pylori treatment should be considered. In this article, an updated critical review of the usefulness of the various invasive and noninvasive tests in the context of extensive PPI use is provided.

Increasing biopsy number and sampling from gastric body improve the sensitivity of rapid urease test in patients with peptic ulcer bleeding

BACKGROUND

Previous studies demonstrated that the sensitivity of rapid urease test (RUT) for diagnosis of Helicobacter pylori infection decreased during peptic ulcer bleeding.

AIM

We designed this study and tried to find a better method to improve the detection rate of H. pylori infection at the same session of endoscopic diagnosis of peptic ulcer bleeding.

METHODS

We prospectively enrolled 116 patients with peptic ulcer bleeding. These patients received intravenous proton pump inhibitor and then received upper gastrointestinal endoscopy within 24 h after arrival. We took one piece of biopsy from gastric antrum (Group 1), four pieces from gastric antrum (Group 2), and one piece from the gastric body (Group 3) for three separate RUTs, respectively. (13)C-urease breath test was used as gold standard for diagnosis of H. pylori infection.

RESULTS

There were 74 patients (64 %) with positive (13)C-urease breath test. Among these 74 patients, 45 patients had positive RUT (sensitivity: 61 %) in Group 1; 55 patients had positive RUT (sensitivity: 74 %) in Group 2; 54 patients had positive RUT (sensitivity: 73 %) in Group 3. There were significant differences between Group 1 and Group 2 (p = 0.02) and between Group 1 and Group 3 (p = 0.022).

CONCLUSIONS

The sensitivity of RUT was 61 % during peptic ulcer bleeding. The sensitivity of RUT can be increased significantly by increased biopsy number from gastric antrum or biopsy from gastric body.

Diagnosis, treatment, and outcome in patients with bleeding peptic ulcers and Helicobacter pylori infections

Upper gastrointestinal (UGI) bleeding is the most frequently encountered complication of peptic ulcer disease. Helicobacter pylori (Hp) infection and nonsteroidal anti-inflammatory drug (NSAID) administration are two independent risk factors for UGI bleeding. Therefore, testing for and diagnosing Hp infection are essential for every patient with UGI hemorrhage. The presence of the infection is usually underestimated in cases of bleeding peptic ulcers. A rapid urease test (RUT), with or without histology, is usually the first test performed during endoscopy. If the initial diagnostic test is negative, a delayed ¹³C-urea breath test (UBT) or serology should be performed. Once an infection is diagnosed, antibiotic treatment is advocated. Sufficient evidence supports the concept that Hp infection eradication can heal the ulcer and reduce the likelihood of rebleeding. With increased awareness of the effects of Hp infection, the etiologies of bleeding peptic ulcers have shifted to NSAID use, old age, and disease comorbidity.

Dual-priming oligonucleotide-based multiplex PCR using tissue samples in rapid urease test in the detection of Helicobacter pylori infection

AIM: To investigate whether tissue samples processed by the rapid urease test (RUT) kit are suitable for dual-priming oligonucleotide-based multiplex polymerase chain reaction (DPO-PCR) to detect Helicobacter pylori (H. pylori).

METHODS: A total of 54 patients with specific gastrointestinal symptom were enrolled in this study. During endoscopy, gastric biopsy specimens were taken for histology, RUT, and DPO-PCR. DPO-PCR was performed on gastric biopsy samples and tissue samples that were analyzed by RUT at 2 separate institutes. In detecting H. pylori, the concordance rate of the DPO-PCR tests between the tissue samples that had been submitted to RUT and the gastric biopsy samples was investigated.

RESULTS: H. pylori co-occurred with 76.0% (19/25) of gastric ulcers, 64.3% (9/14) of duodenal ulcers, and 33.3% (4/12) of gastritis cases. H. pylori infection was found in 100% (3/3) of the patients with both gastric and duodenal ulcers. Overall, H. pylori was detected in 35 of 54 (64.8%) patients. The diagnostic sensitivities of histology, RUT, and DPO-PCR were 85.7% (30/35), 74.3% (26/35), and 97.1% (34/35), respectively (P = 0.02). The positive predictive value (PPV) of DPO-PCR was 94.4%, whereas the negative predictive value (NPV) was 94.7%. In the rapid urease test (CLOtest)-negative cases, the frequency of positive DPO-PCR and histologic results was 20.0% (7/35). The concordance rate of the DPO-PCR tests between the tissue samples from the RUT kit and the gastric biopsy samples was 94.4% (51/54). The rate of DPO-PCR and silver stain positivity in the RUT-negative cases was 20.0% (7/35).

CONCLUSION: In diagnosing H. pylori infection, DPO-PCR can be performed on tissue samples that have been processed by the RUT kit. Particularly, in patients with RUT-negative results, DPO-PCR on these tissue samples could be helpful in detecting of H. pylori infection.

Long-term follow-up of 1,000 patients cured of Helicobacter pylori infection following an episode of peptic ulcer bleeding

OBJECTIVES

To evaluate the effect of Helicobacter pylori (H. pylori) eradication on ulcer bleeding recurrence in a prospective, long-term study including 1,000 patients.

METHODS

Patients with peptic ulcer bleeding were prospectively included. Prior non-steroidal anti-inflammatory drug (NSAID) use was not considered exclusion criteria. H. pylori infection was confirmed by rapid urease test, histology, or (13)C-urea breath test. Several eradication therapies were used. Subsequently, ranitidine 150 mg o.d. was administered until eradication was confirmed by (13)C-urea breath test 8 weeks after completing therapy. Patients with therapy failure received a second, third, or fourth course of eradication therapy. Patients with eradication success did not receive maintenance anti-ulcer therapy and were controlled yearly with a repeat breath test. NSAID use was not permitted during follow-up.

RESULTS

Thousand patients were followed up for at least 12 months, with a total of 3,253 patient-years of follow-up. Mean age 56 years, 75% males, 41% previous NSAID users. In all, 69% had duodenal ulcer, 27% gastric ulcer, and 4% pyloric ulcer. Recurrence of bleeding was demonstrated in three patients at 1 year (which occurred after NSAID use in two cases, and after H. pylori reinfection in another one), and in two more patients at 2 years (one after NSAID use and another after H. pylori reinfection). The cumulative incidence of rebleeding was 0.5% (95% confidence interval, 0.16-1.16%), and the incidence rate of rebleeding was 0.15% (0.05-0.36%) per patient-year of follow up.

CONCLUSION

Peptic ulcer rebleeding virtually does not occur in patients with complicated ulcers after H. pylori eradication. Maintenance anti-ulcer (antisecretory) therapy is not necessary if eradication is achieved. However, NSAID intake or H. pylori reinfection may exceptionally cause rebleeding in H. pylori-eradicated patients.

Accuracy of urea breath test performed immediately after emergency endoscopy in peptic ulcer bleeding

AIMS

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Management of non-variceal upper gastrointestinal tract hemorrhage: Controversies and areas of uncertainty

Upper gastrointestinal tract hemorrhage (UGIH) remains a common presentation requiring urgent evaluation and treatment. Accurate assessment, appropriate intervention and apt clinical skills are needed for proper management from time of presentation to discharge. The advent of pharmacologic acid suppression, endoscopic hemostatic techniques, and recognition of Helicobacter pylori as an etiologic agent in peptic ulcer disease (PUD) has revolutionized the treatment of UGIH. Despite this, acute UGIH still carries considerable rates of morbidity and mortality. This review aims to discuss current areas of uncertainty and controversy in the management of UGIH. Neoadjuvant proton pump inhibitor (PPI) therapy has become standard empiric treatment for UGIH given that PUD is the leading cause of non-variceal UGIH, and PPIs are extremely effective at promoting ulcer healing. However, neoadjuvant PPI administration has not been shown to affect hard clinical outcomes such as rebleeding or mortality. The optimal timing of upper endoscopy in UGIH is often debated. Upon completion of volume resuscitation and hemodynamic stabilization, upper endoscopy should be performed within 24 h in all patients with evidence of UGIH for both diagnostic and therapeutic purposes. With rising healthcare cost paramount in today’s medical landscape, the ability to appropriately triage UGIH patients is of increasing value. Upper endoscopy in conjunction with the clinical scenario allows for accurate decision making concerning early discharge home in low-risk lesions or admission for further monitoring and treatment in higher-risk lesions. Concomitant pharmacotherapy with non-steroidal anti-inflammatory drugs (NSAIDs) and antiplatelet agents, such as clopidogrel, has a major impact on the etiology, severity, and potential treatment of UGIH. Long-term PPI use in patients taking chronic NSAIDs or clopidogrel is discussed thoroughly in this review.

Management of non-variceal upper gastrointestinal tract hemorrhage: controversies and areas of uncertainty

Upper gastrointestinal tract hemorrhage (UGIH) remains a common presentation requiring urgent evaluation and treatment. Accurate assessment, appropriate intervention and apt clinical skills are needed for proper management from time of presentation to discharge. The advent of pharmacologic acid suppression, endoscopic hemostatic techniques, and recognition of Helicobacter pylori as an etiologic agent in peptic ulcer disease (PUD) has revolutionized the treatment of UGIH. Despite this, acute UGIH still carries considerable rates of morbidity and mortality. This review aims to discuss current areas of uncertainty and controversy in the management of UGIH. Neoadjuvant proton pump inhibitor (PPI) therapy has become standard empiric treatment for UGIH given that PUD is the leading cause of non-variceal UGIH, and PPIs are extremely effective at promoting ulcer healing. However, neoadjuvant PPI administration has not been shown to affect hard clinical outcomes such as rebleeding or mortality. The optimal timing of upper endoscopy in UGIH is often debated. Upon completion of volume resuscitation and hemodynamic stabilization, upper endoscopy should be performed within 24 h in all patients with evidence of UGIH for both diagnostic and therapeutic purposes. With rising healthcare cost paramount in today's medical landscape, the ability to appropriately triage UGIH patients is of increasing value. Upper endoscopy in conjunction with the clinical scenario allows for accurate decision making concerning early discharge home in low-risk lesions or admission for further monitoring and treatment in higher-risk lesions. Concomitant pharmacotherapy with non-steroidal anti-inflammatory drugs (NSAIDs) and antiplatelet agents, such as clopidogrel, has a major impact on the etiology, severity, and potential treatment of UGIH. Long-term PPI use in patients taking chronic NSAIDs or clopidogrel is discussed thoroughly in this review.

Evaluation of the effect of presence of blood in the stomach on endoscopic diagnostic tests for Helicobacter pylori infection

INTRODUCTION

Presence of blood in the stomach has been thought to affect the performance of diagnostic tests used in detecting Helicobacter pylori (H. pylori) in the stomach. This study evaluated the effect of blood on the efficacy of rapid urease test (RUT) and microscopic appearance of the biopsy after staining with Giemsa stain.

MATERIALS AND METHODS

Patients with bleeding oesophageal varices who met the inclusion criteria were tested for H. pylori by RUT and microscopic examination of the biopsy. A repeat endoscopy, RUT and histology were done one month following initial presentation. The performance of the diagnostic tests was evaluated with and without the presence of intraluminal blood. A combined result of the two tests, RUT and histology, carried out in presence or absence of blood for the diagnosis of H. pylori, when considered together was considered as the gold standard.

RESULTS

Thirty six patients included in the study were in the ages ranging between 15-60 years (mean age = 44.14 years ± 2.1). The combination of tests at both visits showed 20/36 (55.6%) patients were positive for H. pylori. The decrease in H. pylori positivity in the presence of blood was significant for RUT (8.3% vs. 38.9%; P=0.005) and combined test (19.4% vs. 47.2%; P=0.02) but the decrease in positivity for histology (11.1% vs 30.6%) was not significant (P=0.08). In the presence of blood, the sensitivity of RUT, histology and combined tests were 15%, 20% and 35%, respectively. In the absence of blood, the sensitivity of RUT, histology and combination of tests was 70%, 55% and 85%, respectively.

CONCLUSION

Blood in the stomach significantly decreased the sensitivity of RUT, histology and the combination of both. Negative results of these tests in acute upper gastro intestinal (GI) bleeding should therefore be interpreted carefully.

Real-time PCR improves Helicobacter pylori detection in patients with peptic ulcer bleeding

BACKGROUND AND AIMS

Histological and rapid urease tests to detect H. pylori in biopsy specimens obtained during peptic ulcer bleeding episodes (PUB) often produce false-negative results. We aimed to examine whether immunohistochemistry and real-time PCR can improve the sensitivity of these biopsies.

PATIENTS AND METHODS

We selected 52 histology-negative formalin-fixed paraffin-embedded biopsy specimens obtained during PUB episodes. Additional tests showed 10 were true negatives and 42 were false negatives. We also selected 17 histology-positive biopsy specimens obtained during PUB to use as controls. We performed immunohistochemistry staining and real-time PCR for 16S rRNA, ureA, and 23S rRNA for H. pylori genes on all specimens.

RESULTS

All controls were positive for H. pylori on all PCR assays and immunohistochemical staining. Regarding the 52 initially negative biopsies, all PCR tests were significantly more sensitive than immunohistochemical staining (p<0.01). Sensitivity and specificity were 55% and 80% for 16S rRNA PCR, 43% and 90% for ureA PCR, 41% and 80% for 23S rRNA PCR, and 7% and 100% for immunohistochemical staining, respectively. Combined analysis of PCR assays for two genes were significantly more sensitive than ureA or 23S rRNA PCR tests alone (p<0.05) and marginally better than 16S rRNA PCR alone. The best combination was 16S rRNA+ureA, with a sensitivity of 64% and a specificity of 80%.

CONCLUSIONS

Real-time PCR improves the detection of H. pylori infection in histology-negative formalin-fixed paraffin-embedded biopsy samples obtained during PUB episodes. The low reported prevalence of H. pylori in PUB may be due to the failure of conventional tests to detect infection.

Advances in understanding relationship between Helicobacter pylori infection and peptic ulcer bleeding

Helicobacter pylori (H.pylori) is a definite causative factor for peptic ulcer; however, its role in peptic ulcer bleeding is not very clear. Detection of H.pylori infection in patients with peptic ulcer bleeding is often affected by methods and drugs used. H.pylori infection increases, to some extent, the risk of peptic ulcer bleeding. Eradication of H.pylori may reduce the risk of peptic ulcer bleeding and promote ulcer healing.

Has H. pylori prevalence in bleeding peptic ulcer been underestimated? A meta-regression

OBJECTIVES

It has been suggested that prevalence of Helicobacter pylori (Hp) in peptic ulcer bleeding (PUB) is lower than that in non-complicated ulcers. As Hp infection is elusive in PUB, we hypothesized that this low prevalence could be related to an insufficiently intensive search for the bacteria. The aim of the study was to evaluate whether the prevalence of Hp in PUB depends on the diagnostic methods used in a given study.

METHODS

A systematic review was performed of studies assessing the prevalence of Hp infection in patients with PUB. Data were extracted in duplicate. Univariate and multivariate random-effects meta-regression analyses were performed to determine the factors that explained the differences in Hp prevalence between studies.

RESULTS

The review retrieved 71 articles, including 8,496 patients. The mean prevalence of Hp infection in PUB was 72%. The meta-regression analysis showed that the most significant variables associated with a high prevalence of Hp infection were the use of a diagnostic test delayed until at least 4 weeks after the PUB episode-odds ratio: 2.08, 95% confidence interval: 1.10-3.93, P=0.024-and a lower mean age of patients-odds ratio: 0.95 per additional year, 95% confidence interval: 0.92-0.99, P=0.008.

CONCLUSIONS

Studies that performed a delayed test and those including younger patients found a higher prevalence of Hp, approaching that recorded in cases of non-bleeding ulcers. These results suggest that the low prevalence of Hp infection described in PUB may be related to the methodology of the studies and to patients' characteristics, and that the true prevalence of Hp in PUB is still to be determined. Our data also support the recent recommendations of the International Consensus on Non-Variceal Upper Gastrointestinal Bleeding regarding the performance of a delayed diagnostic test when Hp tests carried out during the acute PUB episode are negative.

What is the best strategy for diagnosis and treatment of Helicobacter pylori in the prevention of recurrent peptic ulcer bleeding? A cost-effectiveness analysis

BACKGROUND

Clinical trials provide evidence of the high effectiveness of Helicobacter pylori eradication for preventing recurrent ulcer-related gastrointestinal hemorrhage. The best strategy for curing the infection in this setting is, however, still under debate.

OBJECTIVE

To evaluate four different strategies for prevention of rebleeding in patients with peptic ulcer hemorrhage: 1) test for H. pylori and treatment, if positive; 2) proton pump inhibitor maintenance; 3) no preventive treatment; 4) empirical H. pylori eradication immediately after bleeding.

METHODS

A decision analysis model was used, with a time horizon of 2 years and a third-party payer perspective. Costs were estimated for two different settings: a low-cost-for-care area (Spain) and a high-cost area (USA). Main outcome measure was incremental cost-effectiveness ratio for each upper gastrointestinal hemorrhage avoided.

RESULTS

Empirical H. pylori eradication was the dominant strategy: its estimated rate of recurrent bleeding was lower (6.1%) than those of strategies 1 (7.4%), 2 (11.1%), and 3 (18.4%) and it was the least expensive strategy. The results remained stable when variables were changed inside a wide range of plausible values. Sensitivity analysis also showed that the prevalence of H. pylori in bleeding ulcer was the variable that most influenced the results: when it was below 45% in Spain or below 51% in the United States, empirical eradication was not a dominant strategy although it remained cost-effective.

CONCLUSION

In patients with bleeding peptic ulcer, empirical treatment of H. pylori infection immediately after feeding is restarted is the most cost-effective strategy for preventing recurrent hemorrhage.

Endoscopic diagnosis of Helicobacter pylori infection by rapid urease test in bleeding peptic ulcers: a prospective case-control study

GOAL

To assess the efficacy of rapid urease test (RUT) in patients with bleeding ulcers, as well as the effects of visible blood in the stomach and short-term (<24 h) use of standard-dose proton pump inhibitor (PPI) on RUT sensitivity.

BACKGROUND

The sensitivity of RUT in the diagnosis of Helicobacter pylori in upper gastrointestinal bleeding has been reported with conflicting results.

STUDY

This was a prospective case-control study evaluating 324 consecutive patients with bleeding peptic ulcers (study group) and 164 with uncomplicated ulcers (control group). The presence of H. pylori infection was determined by both RUT and histology. Prevalence of H. pylori infection and the RUT sensitivity in diagnosing the bacteria between study and control groups were conducted.

RESULTS

The prevalence of H. pylori infection in those with bleeding ulcers was significantly lower than that of controls (53.7% vs. 65.2%, P=0.015). The false-negative rate of RUT in the study group was significantly greater than that of the control group (16.7% vs. 5.6%, P=0.006), whereas the sensitivity rates in the study group with or without gastric blood were significantly lower than those of the controls (79.6% vs. 94.4%, P=0.005; 84.8% vs. 94.4%, P=0.019). There was no significant difference in RUT sensitivity between study group with or without visible gastric blood (P=0.41). The RUT sensitivity rate was also not significantly different between those treated with PPI and those without in patients with bleeding ulcers (82.7% vs. 85.7%, P=0.67).

CONCLUSIONS

This study shows that the sensitivity of RUT in patients with bleeding ulcers is reduced. The presence of blood in the stomach and the short-term use of standard-dose PPI do not affect the RUT sensitivity in bleeding ulcers.

American College of Gastroenterology guideline on the management of Helicobacter pylori infection

Helicobacter pylori (H. pylori) remains a prevalent, worldwide, chronic infection. Though the prevalence of this infection appears to be decreasing in many parts of the world, H. pylori remains an important factor linked to the development of peptic ulcer disease, gastric malignanc and dyspeptic symptoms. Whether to test for H. pylori in patients with functional dyspepsia, gastroesophageal reflux disease (GERD), patients taking nonsteroidal antiinflammatory drugs, with iron deficiency anemia, or who are at greater risk of developing gastric cancer remains controversial. H. pylori can be diagnosed by endoscopic or nonendoscopic methods. A variety of factors including the need for endoscopy, pretest probability of infection, local availability, and an understanding of the performance characteristics and cost of the individual tests influences choice of evaluation in a given patient. Testing to prove eradication should be performed in patients who receive treatment of H. pylori for peptic ulcer disease, individuals with persistent dyspeptic symptoms despite the test-and-treat strategy, those with H. pylori-associated MALT lymphoma, and individuals who have undergone resection of early gastric cancer. Recent studies suggest that eradication rates achieved by first-line treatment with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin have decreased to 70-85%, in part due to increasing clarithromycin resistance. Eradication rates may also be lower with 7 versus 14-day regimens. Bismuth-containing quadruple regimens for 7-14 days are another first-line treatment option. Sequential therapy for 10 days has shown promise in Europe but requires validation in North America. The most commonly used salvage regimen in patients with persistent H. pylori is bismuth quadruple therapy. Recent data suggest that a PPI, levofloxacin, and amoxicillin for 10 days is more effective and better tolerated than bismuth quadruple therapy for persistent H. pylori infection, though this needs to be validated in the United States.

13C-urea breath test during hospitalization for the diagnosis of Helicobacter pylori infection in peptic ulcer bleeding

OBJECTIVE

To evaluate the accuracy of (13)C-urea breath test (UBT) to detect Helicobacter pylori infection in patients hospitalized with peptic ulcer bleeding and treated with proton pump inhibitors (PPIs).

METHODS

Patients hospitalized with peptic ulcer bleeding, and treated with omeprazole, had a first UBT performed the day after resuming oral feeding. Patients with a negative UBT during hospitalization underwent a repeated UBT 15 days after stopping PPIs.

RESULTS

The first UBT during hospitalization was positive in 86% of 131 patients. Time between admission and performance of the test was longer in patients with negative versus positive UBT (5.2 +/- 0.7 versus 4.3 +/- 0.5 days; p < .001). The repeated UBT became positive in 15 of 18 (83%) patients with a negative first UBT. In the multivariate analysis, the only variable associated with a negative first UBT was the time elapsed between admission and performance of the test (odds ratio = 6.6; 95%CI = 2.9-15.1).

CONCLUSION

Most H. pylori-positive patients with ulcer bleeding have a positive UBT (performed just after resuming oral feeding) despite previous treatment with high-dose PPIs. Nevertheless, to preclude false-negative results due to PPI therapy, the UBT should be performed as early as possible. If the infection cannot be demonstrated with this first UBT, H. pylori still needs to be definitively excluded with a second UBT performed after stopping PPIs.