Correlation of serology with morphological changes in gastric biopsy in Helicobacter pylori infection and evaluation of immunohistochemistry for H. pylori identification

Effect of Helicobacter pylori infection on survival outcomes of patients undergoing radical gastrectomy after neoadjuvant chemotherapy: a multicenter study in China

BACKGROUND

Neoadjuvant chemotherapy (NAC) has been confirmed to improve the prognosis of patients with advanced gastric cancer (AGC). However, no study has investigated whether Helicobacter pylori (HP) infection affects the postoperative survival of patients who receive NAC.

METHODS

This retrospective cohort study included 307 patients with AGC who underwent laparoscopic radical gastrectomy after NAC at three hospitals in China between January 1, 2016, and April 31, 2020. Cox regression was used to assess prognostic factors for survival. Kaplan-Meier was used for survival analysis.

RESULTS

The HP + and the HP- group included 141 and 166 cases. The 3-year overall survival (OS) and disease-free survival (DFS) of the HP + group were significantly better than the HP- group (3-year OS: 75.9% vs. 60.2%, 3-year DFS: 70.2% vs. 52.3%; All P < 0.001). For the HP + group, ypTNM Stage III (HR, 4.00; 95% CI, 1.11-14.39; P = 0.034), NAC ≥ 4 cycles (HR, 0.43; 95% CI, 0.20-0.90; P = 0.026), and adjuvant chemotherapy (AC) ≥ 4 cycles (HR, 0.20; 95% CI, 0.09-0.48; P < 0.001) are independent prognostic factors for OS. In the cohort of HP + patients who received ≥ 4 cycles of NAC, the prognosis of patients who received ≥ 4 cycles of AC after surgery was better than that of patients who received < 4 cycles of AC (3-year OS: 92.5% vs 71.4%; P = 0.042).

CONCLUSIONS

Following NAC, HP + patients with AGC exhibit better prognosis than that of HP- counterparts. For potentially resectable HP + AGC patients, radical surgery following ≥ 4 cycles of NAC with ≥ 4 cycles of sequential AC might be recommended to improve survival.

Evaluation of guidelines for diagnosis and treatment of Helicobacter pylori infection

BACKGROUND

To systematically evaluate the quality of the guidelines for the diagnosis and treatment of Helicobacter pylori infection and to analyze the differences and reasons for the key recommendations in the guidelines.

METHODS

Databases and websites were systematically searched to obtain guidelines for the diagnosis and treatment of Helicobacter pylori infection. Four independent reviewers used the Guideline Evaluation Tool (AGREE II) to evaluate the included guidelines. The intraclass correlation coefficient (ICC) and Fleiss' kappa coefficient were used to measure the consistency of evaluation guidelines between guide reviewers. Differences between guidelines and the reasons for the differences were analyzed by comparing the recommendations of different guidelines and the evidence supporting the recommendations.

RESULTS

A total of 17 guidelines for Helicobacter pylori infection were included in this study. The AGREE II scores of these guidelines were low overall, with 4 of them had a score of over 60%, which indicates that the guidelines are recommended, and 13 of them having a score ranging from 30 to 60%, which indicates that the guidelines are recommended but need to be revised, while no guideline had a score of 30% or less, which indicates that they were not recommended. The analysis of these guidelines found that there were some differences in the main recommendations. Not all guidelines recommend sequential therapy as the recommended therapy. Whether bismuth quadruple therapy should be used as the recommended first-line therapy is unclear. The antibiotic resistance rate is different in different regions. Combined with the local antibiotic sensitivity test, the eradication rate of Helicobacter pylori can be improved.

CONCLUSION

There are significant differences in the quality of Helicobacter pylori infection guidelines and the key recommendations. Improving the deficiencies of existing guidelines is an effective way to develop high-quality guidelines and make reasonable recommendations for the treatment of Helicobacter pylori infection in the future.

Evolution of Diagnostic Methods for Helicobacter pylori Infections: From Traditional Tests to High Technology, Advanced Sensitivity and Discrimination Tools

Rapid diagnosis and treatment application in the early stages of H. pylori infection plays an important part in inhibiting the transmission of this infection as this bacterium is involved in various gastric pathologies such as gastritis, gastro-duodenal ulcer, and even gastric neoplasia. This review is devoted to a quick overview of conventional and advanced detection techniques successfully applied to the detection of H. pylori in the context of a compelling need to upgrade the standards of the diagnostic methods which are currently being used. Selecting the best diagnostic method implies evaluating different features, the use of one or another test depending on accessibility, laboratories equipment, and the clinical conditions of patients. This paper aims to expose the diagnosis methods for H. pylori that are currently available, highlighting their assets and limitations. The perspectives and the advantages of nanotechnology along with the concept of nano(bio)sensors and the development of lab-on-chip devices as advanced tools for H. pylori detection, differentiation, and discrimination is also presented, by emphasizing multiple advantages: simple, fast, cost-effective, portable, miniaturized, small volume of samples required, highly sensitive, and selective. It is generally accepted that the development of intelligent sensors will completely revolutionize the acquisition procedure and medical decision in the framework of smart healthcare monitoring systems.

Immunohistochemical diagnosis of human infectious diseases: a review

BACKGROUND

Immunohistochemistry (IHC) using monoclonal and polyclonal antibodies is a useful diagnostic method for detecting pathogen antigens in fixed tissues, complementing the direct diagnosis of infectious diseases by PCR and culture on fresh tissues. It was first implemented in a seminal publication by Albert Coons in 1941.

MAIN BODY

Of 14,198 publications retrieved from the PubMed, Google, Google Scholar and Science Direct databases up to December 2021, 230 were selected for a review of IHC techniques, protocols and results. The methodological evolutions of IHC and its application to the diagnosis of infectious diseases, more specifically lice-borne diseases, sexually transmitted diseases and skin infections, were critically examined. A total of 59 different pathogens have been detected once in 22 different tissues and organs; and yet non-cultured, fastidious and intracellular pathogens accounted for the vast majority of pathogens detected by IHC. Auto-IHC, incorporating patient serum as the primary antibody, applied to diseased heart valves surgically collected from blood culture-negative endocarditis patients, detected unidentified Gram-positive cocci and microorganisms which were subsequently identified as Coxiella burnetii, Bartonella quintana, Bartonella henselae and Tropheryma whipplei. The application of IHC to ancient tissues dated between the ends of the Ptolemaic period to over 70 years ago, have also contributed to paleomicrobiology diagnoses.

CONCLUSION

IHC plays an important role in diagnostic of infectious diseases in tissue samples. Paleo-auto-IHC derived from auto-IHC, is under development for detecting non-identified pathogens from ancient specimens.

The Patterns and Associated Cost of Serologic Testing for Helicobacter pylori in the U.S. Military Health System

INTRODUCTION

Helicobacter pylori (H. pylori) infection affects about half of the world's population and can lead to multiple complications if left untreated. Testing for H. pylori infection in appropriate patients with prompt treatment followed by the testing of eradication is the standard of care in the United States. Active Duty Service members (ADSMs) in the U.S. military are a unique patient population that may be at higher risk for acquiring H. pylori infection given frequent deployments to developing countries. Noninvasive diagnostic strategies include the urea breath test, the stool antigen test, and serologic testing, which include H. pylori immunoglobulin M (IgM), immunoglobulin A (IgA), and immunoglobulin G (IgG) antibodies. Among noninvasive methods, the least sensitive is serology, and although there is clinical utility in testing for H. pylori IgG antibodies, H. pylori IgA or IgM antibodies have limited clinical utility. Despite this, H. pylori IgA and IgM antibodies are still widely ordered across the Military Health System.

MATERIALS AND METHODS

In order to determine how frequently this testing is being ordered and the associated cost, we conducted a retrospective cross-sectional study of H. pylori serologic testing utilization in the MHS from October 2015 to September 2018 in adult patients using the MHS Data Repository. All H. pylori IgM, IgA, and IgG antibodies, H. pylori stool antigen tests, and H. pylori urea breath tests were queried during this time period across all ADSMs, retirees, and ADSM dependents for all adults. Cost information was obtained from LabCorp, and the institutional price used for cost analysis was the same throughout all military treatment facilities in the Department of Defense (DOD).

RESULTS

We discovered that over a 3-yr period, 1,916 H. pylori IgA and 2,492 IgM antibodies were ordered. In total, the DOD spent close to $400,000 on antibody-based testing for H. pylori not accounting for indirect associated costs like personnel, supplies, repeat testing, as well as the costs of delayed diagnosis and associated complications.

CONCLUSION

H. pylori IgM and IgA have limited clinical utility, are inaccurate, and are costly to maintain, especially when more accurate alternative tests are available. Based on our analysis, we strongly recommend the removal of the H. pylori IgA and IgM serologic tests throughout the DOD in order to improve the efficiency and quality of care for patients suspected of having an H. pylori infection. Further research is needed to determine how these tests are ordered, how providers are responding to the results of the serologic tests, and if noninvasive testing is being ordered appropriately.

An Update on the Role of Immunohistochemistry in the Evaluation of Gastrointestinal Tract Disorders

As in other organ systems, immunohistochemistry (IHC) serves as an ancillary diagnostic tool for a wide variety of neoplastic and non-neoplastic disorders, including infections, work-up of inflammatory conditions, and subtyping neoplasms of the gastrointestinal (GI) tract. In addition, IHC is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the GI tract. The purpose of this review is to highlight the use of IHC in common diagnostic scenarios throughout the tubular GI tract. The clinical indication and guidelines for performing IHC for detecting Helicobacter pylori is discussed along with role of gastrin and neuroendocrine markers in the diagnosis of autoimmune metaplastic atrophic gastritis. The major portion of this review discusses the use of IHC in the diagnostic workup of malignant neoplasms of the GI tract, such as adenocarcinoma versus squamous cell carcinoma, workup of poorly differentiated malignant neoplasms, and evaluation of uncommon gastric neoplasms (alpha-feto protein-producing carcinomas) and switch/sucrose-nonfermenting complex-deficient carcinomas. Lastly, localization of neuroendocrine tumors of unknown origin to aid clinical management, as well as HPV-driven anal neoplasia and IHC in the workup of basaloid anal neoplasms are also reviewed.

Detection of Helicobacter pylori with clarithromycin resistance-associated mutations using peptide nucleic acid probe-based melting point analysis

BACKGROUND

Detection of Helicobacter pylori in gastric biopsy is important for appropriate treatment and prevention of gastric carcinoma and lymphoma. A novel peptide nucleic acid probe (PNA)-based real-time polymerase chain reaction (PCR) method was developed for detection of H pylori and A2142G/A2143G mutation of the 23S rRNA gene, which is associated with clarithromycin resistance.

METHODS

To evaluate the performance of the PNA probe-based PCR method, a total of 409 gastric biopsy samples were analyzed by PNA probe-based PCR and compared with other H pylori detection methods, including hematoxylin and eosin (HE) and Warthin-Starry (WS) staining, immunohistochemistry (IHC). A2142G/A2143G mutation of the 23S rRNA gene was tested by dual priming oligonucleotide (DPO)-based PCR and Sanger sequencing to evaluate PNA probe-based PCR.

RESULTS

Among 271 cases that were positive for H pylori on IHC which was considered as a standard method, 264 cases (97.4%) and 259 cases (95.6%) were positively detected by HE/WS and PNA probe-based qPCR, respectively. Of 100 H pylori-positive patients tested by IHC, H pylori was detected in 93 cases (93.0%) by PNA probe-based PCR, 86 cases (86.0%) by DPO-based PCR, and 93 cases (93.0%) by conventional PCR. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PNA probe-based qPCR were 93.0%, 94.9%, 93.9%, 94.9%, and 93.0%, respectively, which were all higher than those of DPO-based PCR. When Sanger sequencing was determined as a standard method to detect A2142G/A2143G mutations, the sensitivity of the PNA- and DPO-based methods was 100% and 94.4%, respectively, and the specificity was 100% for both methods.

CONCLUSION

PNA probe-based qPCR is an appropriate method for detecting H pylori and the clarithromycin resistance-associated mutation type.

Antigen of 49.6-kDa subunitpili protein of Helicobacter pylori as a potential biomarker for early and rapid detection of the infection

Background and Aim:

Helicobacter pylori infection has been identified as a major cause of peptic ulcer diseases, including gastric and duodenal ulcers, gastritis, chronic and gastric carcinoma, and even gastric lymphoma. In vitro studies using Western blotting analysis, hemagglutination test, adherence inhibition assays, and immunocytochemical staining revealed that the 49.6-kDa subunit pili protein of H. pylori was considered an immunogenic protein. This study aimed to develop a serological diagnostic test using 49.6 kDa for detecting antibodies against H. pylori proteins in an early phase of the infection.

Materials and Methods:

An in-house immunochromatographic test (ICT) kit was developed and used to test a panel of sera sample obtained from a randomly selected symptomatic patient, in which 40 sera were H. pylori positive and 40 sera were H. pylori negative.

Results:

The results showed that ICT with 49.6 kDa as an antigen was highly sensitive and specific for detecting anti-H. pylori immunoglobulin G antibodies in human serum, with a high negative predictive value.

Conclusion:

The developed test could be used to exclude H. pylori infection in symptomatic patients.

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.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Real-world Helicobacter pylori diagnosis in patients referred for esophagoduodenoscopy: The gap between guidelines and clinical practice

BACKGROUND AND AIMS

Histopathology is the most accurate test to detect H. pylori when performed correctly with unknown validity in daily practice clinic settings. We aimed to determine the rate of potentially false-negative H. pylori results that might be due to continued use of proton pump inhibitors (PPIs) in routine endoscopy practice. We also aimed to establish whether gastroenterologists recommend routine cessation of PPIs before esophagogastroduodenoscopy (EGD) and whether they regularly document that biopsies for H. pylori testing have been taken while the patients are on PPI treatment.

METHODS

Detailed information about three known factors (PPIs, antibiotics and prior H. pylori eradication treatment), which may cause histology or rapid urease test (RUT) to be unreliable, had been prospectively collected through interviews using a questionnaire before each test. Gastric biopsies were stained with H&E for histological analysis.

RESULTS

A total of 409 individuals at three academic gastroenterology institutions were tested 200 times with histology. Fifty-six per cent (68 of 122) of all negative tests fell in the category of continuing PPI use, which had the potential to make the histology and RUT results unreliable.

CONCLUSIONS

These data demonstrate a clear and important gap between current guidelines and real-world practice with regards to the diagnosis of H. pylori during EGD. A negative histology or RUT should be considered false negative until potential protocol violations are excluded. Documentation of PPI use during the EGD should be an integral part of the EGD report. The current practice of taking biopsies for H. pylori testing in patients under PPIs should be reevaluated.

MicroRNA-155-enhanced autophagy in human gastric epithelial cell in response to Helicobacter pylori

BACKGROUND/AIM

MicroRNAs (miRNAs) are a class of small noncoding RNAs acting as posttranscriptional gene expression regulators in many physiological and pathological conditions. MiR-155 is one kind of miRNAs that plays an important role in causing various diseases. However, the precise molecular mechanism of the ectopic expression of miR-155 in Helicobacter pylori infection remains poorly understood. Autophagy has recently been identified as an effective way to control the intracellular bacterium survival. In the present study, we demonstrate a novel role of miR-155 in regulating the autophagy-mediated anti-H. pylori response.

PATIENTS AND METHODS

Totally 86 H. pylori-positive patients together with 10 H. pylori-negative, healthy control subjects were included in the study. Correlation between immunohistochemical grades and miR-155 expression were determined. Molecular mechanism of miR-155 on regulation of autophagy and elimination of intracellular H. pylori were determined using the GES-1 cell model.

RESULTS

We found that overexpression of miR-155 by transfecting miR-155 mimics could significantly decrease the survival of intracellular H. pylori, and this process was through induction of autophagy. Furthermore, there was a significant correlation between miR-155 and immunohistochemical grades in H. pylori-positive patients, and miR-155 expression were decreased in the intestinal metaplasia group.

CONCLUSIONS

The results have indicated that the miR-155 expression level plays a key role in immunity response against H. pylori and this might provide potential targets for the future treatment of H. pylori-related diseases.