Comparison of carbon-14-urea breath test and rapid urease test with gastric biopsy for identification of Helicobacter pylori

A pilot study of non-invasive diagnostic tools to detect Helicobacter pylori infection and peptic ulcer disease

Helicobacter pylori (H. pylori) infection can lead to various digestive system diseases, making accurate diagnosis crucial. However, not all available tests are equally non-invasive and sensitive. This study aimed to compare the efficacy of non-invasive and invasive diagnostic tools for H. pylori infection and assess their correlation with esophagogastroduodenoscopic (EGD) findings. The study utilized the Campylobacter-Like Organism (CLO) test, serum anti-HP IgG blood test, and C-13-urea breath test (UBT) to diagnose H. pylori infection. A total of 100 patients with peptic ulcer symptoms, including 45 males and 55 females, were recruited for the study. Symptomatic patients between the ages of 20-70, eligible for EGD examination, were enrolled. Each diagnostic test and any combination of two positive tests were considered the reference standard and compared against the other diagnostic methods. Additionally, the relationship between these diagnostic tests and EGD findings was evaluated. Among the participants, 74.0% were diagnosed with peptic ulcer disease through EGD. The UBT demonstrated the highest Youden's index, ranging from 58 to 100%, against all the non-invasive tests. The IgG blood test displayed the highest sensitivity at 100%, with a specificity of 60-70%. On the other hand, the CLO test exhibited the highest specificity at 100% and a sensitivity of 50-85%. Furthermore, only the CLO test showed a significant association with esophageal ulcers (p-value = 0.01). The IgG blood test holds promise as a primary screening tool due to its exceptional sensitivity. While the UBT is relatively expensive, its non-invasive nature and high sensitivity and specificity make it a potential standalone diagnostic test for H. pylori infection. Moreover, the noteworthy negative correlation between the CLO test and esophageal ulcers provides evidence of the differing effects of H. pylori infection on antral-predominant and corpus-predominant gastritis.

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

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

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.

Focal enhanced gastritis and macrophage microaggregates in the gastric mucosa: potential role in the differential diagnosis between Crohn's disease and ulcerative colitis

CONTEXT AND OBJECTIVES

Focally enhanced gastritis and macrophage microaggregates are found in the upper gastrointestinal involvement of Crohn's disease, and may reflect an underlying defective innate immunity. These features, however, are also described in patients with Helicobacter pylori infection. The role of these gastric abnormalities in the diagnosis of Crohn's disease was assessed in a population with high prevalence of H. pylori infection.

METHODS

Thirty-seven Crohn's disease, 26 ulcerative colitis, and 30 control patients were included. The H. pylori status was evaluated by the rapid urease test and histology. The presence of focally enhanced gastritis and macrophage microaggregates was recorded.

RESULTS

Focally enhanced gastritis was present in 24% of Crohn's disease patients, 4% of ulcerative colitis patients and 11.5% of controls, presenting an overall sensitivity and specificity for Crohn's disease of 24% and 88%, respectively. Macrophage microaggregates were found in all groups, but were only detected in ulcerative colitis and controls in association with H. pylori infection, with an overall sensitivity and specificity for Crohn's disease of 61% and 69%, respectively. In the absence of H. pylori infection, focally enhanced gastritis and macrophage microaggregates were significantly associated with Crohn's disease (P<0.02 and P = 0.001 respectively).

CONCLUSIONS

Focally gastritis and macrophage microaggregates are suggestive of Crohn's disease only in H. pylori-negative specimens.

Distinctiveness of the cagA genotype in children and adults with peptic symptoms in South China

BACKGROUND

Helicobacter pylori infection is different between children and adults, not only in infection rate but also in virulence genotypes. However, the 3' region of CagA, important in stomach carcinogenesis, still remains unclear in children. The present study aims to compare the frequency of cagA and the distribution of its subtypes between children and adults in South China.

MATERIALS AND METHODS

One hundred and twenty-eight children and 99 adults with peptic symptoms were enrolled in our research. Histology, rapid urease test, and real-time polymerase chain reaction (PCR) assay were used to diagnose H. pylori infection. vacA s1 was detected by real-time PCR, and EPIYA motifs in the 3' region of CagA by conventional PCR and DNA sequencing.

RESULTS

H. pylori infection was diagnosed in 53 children and 62 adults. vacA s1 was identified in 90.6% and 91.9% of infected children and adults, respectively. Furthermore, cagA was identified in 73.6% and 82.3% of infected children and adults, respectively. No patient with multiple cagA subtypes was observed. A higher prevalence of more virulent cagA genotype was found in children compared to adults (p < .05). Thirty-eight of 39 (97.4%) cagA-positive children were found to have EPIYA-ABD and only one (2.6%) with EPIYA-ABC. In adults, four types of EPIYA motifs--ABC (29.4%), ABD (64.7%), ABAB (2%), and AAD (3.9%)--were identified, and the ABD type was found more commonly in severe diseases, such as atrophic gastritis (53.3%) and gastric cancer (71.4%).

CONCLUSION

cagA genotypes in children and in adults are different, and EPIYA-ABD may have potential clinical implication in the development of gastric cancer in South China.

Detection of Helicobacter Pylori Infection in Dyspeptic Patients by Different Sero-Bacteriological Methods

To evaluate invasive (biopsy related) tests and noninvasive (serological) tests in the diagnosis of H.pylori, ninety-two adults (54 male, 38 female) presenting with dyspepsia were studied after classification into two groups on the basis of endoscopical diagnosis; 46 patients with erosive diseases (gastroduodenal ulcers or gastroduodenal erosions) and 46patients with non-erosive diseases (gastritis or gastroduodenitis). Sera were testedfor anti-H.pylori IgG and IgM by an immunochromatography card test and ELISA respectively. Three antral biopsies were taken for biopsy urease test (BUT), bacterial culture and histological examination. Stool samples were obtained from only 30 dyspeptic cases for H.pylori antigen detection (HpSA) by an ELISA method.

H. pylori was detected in 81 of 92 cases; these were positive by one or more of the gold standard tests (culture, histology and biopsy-urease test). Histological examination yielded the highest frequency of microorganism detection (71.7%), followed by BUT (68.5%) and then bacterial culture (26.1%). In erosive disorders the BUT gave the highest frequency ofpositivity (78.3%),followed by histological examination (67.4%), and then bacterial culture (41.3%) but in non-erosive disorders histological examination gave the highest positive results (76.1%) followed by BUT (58.7%) and bacterial culture (10.9%). The overall sensitivities of BUT, histology and bacterial culture of H.pylori were 77.8%, 81.5% and 29.6% respectively. Serologically the anti-H.pylori IgG test yielded the highest frequency of positive results (80.4%), followed by HpSA test (66.7%) and the least positive was anti-H.pylori IgM test (65.2%). In the light of the gold standard tests used (biopsy-related tests), the validity of anti-H.pylori IgG test, anti-H.pylori IgM test and HpSA test were determined; the sensitivities being 79%, 65.4% and 75% respectively and their specificities were 9.1%, 36.4% and 66.7% respectively. The positive and negative predictive values, the positive and negative likelihood ratios of serological tests were also evaluated.

Conclusion: The most sensitive invasive test (biopsy related) and noninvasive (serological) tests were histological examination and IgG immunochromatography card tests respectively.