Detection of Helicobacter pylori organisms by Hp-fast in children

Polyethylene microplastics cooperate with Helicobacter pylori to promote gastric injury and inflammation in mice

Microplastics provide stable habitats for the colonization and survival of pathogenic microorganisms, and cooperate with microorganisms to pose a potential threat to human health. In this study, polyethylene microplastics (PE-MPs) in artificial gastric juice time-dependently decomposed and broke into small-diameter PE-MP fragments that were more stable than those in an aqueous solution. Helicobacter pylori adhered to the surfaces of the PE-MPs to form a biofilm. The gastric tissues of mice treated with PE-MPs first and mixture of PE-MPs and H. pylori were positive for H. pylori infection in the 10th and 14th weeks after treatment, whereas those infected with H. pylori first and H. pylori alone were positive only in the 14th week after treatment. PE-MPs were visible in the gastric, intestinal, and liver tissues of mice treated with PE-MPs. The average diameter of the PE-MP fragments in the liver was greater than those of fragments that entered the gastric or intestinal tissues, and the average diameter of PE-MPs in the PE-MPs only-treated mice was significantly smaller than those of PE-MPs entering the intestinal tissues of the other groups. The infiltration of inflammatory cells was most serious in the mice treated with the mixture of PE-MPs and H. pylori, or with PE-MPs first and then H. pylori. Of all the groups, the gastric organ index and MPO, IL6, and TNF-α levels were highest in the mice treated with the mixture of PE-MPs and H. pylori. These results indicate that the interaction between PE-MPs and H. pylori contributed to the rapid bacterial colonization of gastric mucosal epithelial cells, improved the efficiency of PE-MP entry into tissues, and promoted gastric injury and inflammation in mice. These findings suggest that microplastics may provide a stable habitat for H. pylori, and act synergistically with H. pylori to pose a potential threat to human health.

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.

Helicobacter pylori diagnostic tests in children: review of the literature from 1999 to 2009

The array of tests that can be used for diagnosis of Helicobacter pylori infection is large, and it can be confusing to define which test to use particularly in children where results may not be comparable to those obtained in adult patients. Using PubMed, we reviewed the English literature from January 1999 to May 2009 to identify articles that determined sensitivity and specificity of H. pylori invasive and non-invasive diagnostic tests in children. We excluded articles that presented a review of the literature, abstracts, case reports, or series where children's results could not be separated from adult populations. Of the tissue based methods, rapid urease tests have better sensitivity than histology to detect presence of H. pylori; however, histology can detect the pathology associated with disease including gastritis, intestinal metaplasia, and other conditions that could be the cause of the child's symptoms. Culture of gastric tissues or stool has 100% specificity but sensitivity is low. Of the serologic tests, immunoblot has the best sensitivity. The urea breath tests have >75% sensitivity for detection of H. pylori before and after treatment. Immunoassays in stool using monoclonal antibodies have >95% sensitivity for detection of H. pylori before and after treatment. PCR testing can be performed in tissue and stool samples and can detect genes associated to antibiotic resistance. In summary, the current commercial non-invasive tests have adequate sensitivity and specificity for detecting the presence of H. pylori; however, endoscopy with histopathology is the only method that can detect H. pylori and lesions associated with the infection.

Management guidelines for Helicobacter pylori infection: utilization by paediatric gastroenterologists in Australasia

OBJECTIVE

Although there are published guidelines representing the consensus of several large groups, it is unclear whether these are used by practitioners in the management of Helicobacter pylori infection in children and if the guidelines are relevant to particular regions of the world. The aim of this study was to answer these questions in regard to the Australasian region.

METHODS

An email-based questionnaire was circulated to Australasian paediatric gastroenterologists to ascertain aspects of practice related to H. pylori infection in children and to review practitioner awareness and use of the guidelines.

RESULTS

Twenty-five (78%) of 32 questionnaires were completed. Current practice reported by the respondents followed the principles of the published guidelines. However, only 15 gastroenterologists were aware of the guidelines: a number of these practitioners were uncomfortable adapting the published guidelines to their local situation.

CONCLUSIONS

Although widely distributed in the paediatric gastroenterology literature, guidelines for management of H. pylori infection may not be utilized fully by individual practitioners. As these guidelines are updated, based upon current developments in the understanding of H. pylori disease, attempts should be made to ensure that such documents are widely distributed to practitioners and that they reflect regional variations in disease patterns.

Endoscopic nodular gastritis: an endoscopic indicator of high-grade bacterial colonization and severe gastritis in children with Helicobacter pylori

OBJECTIVE

To investigate the significance of endoscopic nodular gastritis associated with Helicobacter pylori infection.

METHODS

This prospective study included 185 children (50.8% boys) aged 1 to 12 years (mean, 6.9 +/- 3.0 years) who underwent upper intestinal endoscopy during evaluation of chronic abdominal pain. The authors assessed the endoscopic appearance of the stomach, noting those patients with endoscopic nodular gastritis. Urease activity of gastric mucosal biopsies was measured. With histologic examination, the presence and density of H. pylori organisms, the presence of follicular gastritis, the nature of inflammation, and the gastritis activity grade and overall gastritis score were assessed.

RESULTS

H. pylori infection was identified in 50 children (27%). Endoscopic nodular gastritis was significantly associated with active chronic gastritis and follicular gastritis. Nodularity in the stomach showed a high specificity (98.5%) and positive predictive value (91.7%) for the diagnosis of H. pylori infection and was observed in 22 of 50 (44%) H. pylori-positive patients and in 2 of 135 (1.5%) H. pylori-negative patients. A significant association was observed between older age and the prevalence of this finding (P< 0.001). There was a significant increase in endoscopic nodular gastritis with increased H. pylori density and a positive correlation (Pearson coefficient = 0.97) with increased gastritis score on histologic examination. Increase in gastritis score was dependent on increased H. pylori density in patients with gastric nodularity; this finding was independent of age.

CONCLUSIONS

Endoscopic findings of antral nodularity in children suggest the presence of H. pylori infection and follicular gastritis and may identify cases of severe gastritis and marked bacterial colonization.

Reuse of negative CLOtest kits in children

BACKGROUND

The rapid urease test, CLOtest, is used frequently in endoscopy suites. In the developed world, a negative CLOtest result is extremely common. The question of whether reuse of previously negative CLOtest kits is appropriate in children and the cost saving of such a practice were investigated.

METHODS

Children who underwent diagnostic endoscopic procedures were prospectively recruited to the study. In each procedure gastric biopsy specimens were obtained for 2 rapid urease tests, one a new kit and the other a used negative kit obtained from previous procedures. In addition gastric specimens were also obtained for routine histologic examination.

RESULTS

In 121 (99.2%) patients a complete concordance between new and used CLOtests was observed. Chi-square analyses showed a significant association between CLOtest results and each of the following factors: gastritis, the presence of Helicobacter pylori organisms, and H pylori-associated gastritis. Assuming an average rate of 15% positive CLOtest results in our pediatric population, the annual savings at the rural hospital was $265 and at the urban children's hospital, $1958.

CONCLUSION

Reuse of a negative CLOtest is reliable and may reduce costs, especially in facilities with a high volume of endoscopic procedures.