Accuracy of Endoscopic Diagnosis for Mild Atrophic Gastritis Infected with Helicobacter pylori

The Diagnostic Performance of Linked Color Imaging Compared to White Light Imaging in Endoscopic Diagnosis of Helicobacter pylori Infection: A Systematic Review and Meta-Analysis

Background/Aims

Recognizing Helicobacter pylori infection during endoscopy is important because it can lead to the performance of confirmatory testing. Linked color imaging (LCI) is an image enhancement technique that can improve the detection of gastrointestinal lesions. The purpose of this study was to compare LCI to conventional white light imaging (WLI) in the endoscopic diagnosis of H. pylori infection.

Methods

We conducted a comprehensive literature search using PubMed, Embase, and the Cochrane Library. All studies evaluating the diagnostic performance of LCI or WLI in the endoscopic diagnosis of H. pylori were eligible. Studies on magnifying endoscopy, chromoendoscopy, and artificial intelligence were excluded.

Results

Thirty-four studies were included in this meta-analysis, of which 32 reported the performance of WLI and eight reported the performance of LCI in diagnosing H. pylori infection. The pooled sensitivity and specificity of WLI in the diagnosis of H. pylori infection were 0.528 (95% confidence interval [CI], 0.517 to 0.540) and 0.821 (95% CI, 0.811 to 0.830), respectively. The pooled sensitivity and specificity of LCI in the diagnosis of H. pylori were 0.816 (95% CI, 0.790 to 0.841) and 0.868 (95% CI, 0.850 to 0.884), respectively. The pooled diagnostic odds ratios of WLI and LCI were 15.447 (95% CI, 8.225 to 29.013) and 31.838 (95% CI, 15.576 to 65.078), respectively. The areas under the summary receiver operating characteristic curves of WLI and LCI were 0.870 and 0.911, respectively.

Conclusions

LCI showed higher sensitivity in the endoscopic diagnosis of H. pylori infection than standard WLI.

Clinical usefulness of linked color imaging in identifying Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

Accurate diagnosis of Helicobacter pylori (H. pylori) infection status is a crucial premise for eradication therapy, as well as evaluation of risk for gastric cancer. Recent progress on imaging enhancement endoscopy (IEE) made it possible to not only detect precancerous lesions and early gastrointestinal cancers but also to predict H. pylori infection in real time. As a novel IEE modality, linked color imaging (LCI) has exhibited its value on diagnosis of lesions of gastric mucosa through emphasizing minor differences of color tone.

AIM

To compare the efficacy of LCI for H. pylori active infection vs conventional white light imaging (WLI).

METHODS

PubMed, Embase, Embase and Cochrane Library were searched up to the end of April 11, 2022. The random-effects model was adopted to calculate the diagnostic efficacy of LCI and WLI. The calculation of sensitivity, specificity, and likelihood ratios were performed; symmetric receiver operator characteristic (SROC) curves and the areas under the SROC curves were computed. Quality of the included studies was chosen to assess using the quality assessment of diagnostic accuracy studies-2 tool.

RESULTS

Seven original studies were included in this study. The pooled sensitivity, specificity, positive likelihood rate, and negative likelihood rate of LCI for the diagnosis of H. pylori infection of gastric mucosa were 0.85 [95% confidence interval (CI): 0.76-0.92], 0.82 (95%CI: 0.78-0.85), 4.71 (95%CI: 3.7-5.9), and 0.18 (95%CI: 0.10-0.31) respectively, with diagnostic odds ratio = 26 (95%CI: 13-52), SROC = 0.87 (95%CI: 0.84-0.90), which showed superiority of diagnostic efficacy compared to WLI.

CONCLUSION

Our results showed LCI can improve efficacy of diagnosis on H. pylori infection, which represents a useful endoscopic evaluation modality for clinical practice.

Role of linked color imaging for upper gastrointestinal disease: present and future

Techniques for upper gastrointestinal endoscopy are advancing to facilitate lesion detection and improve prognosis. However, most early tumors in the upper gastrointestinal tract exhibit subtle color changes or morphological features that are difficult to detect using white light imaging. Linked color imaging (LCI) has been developed to overcome these shortcomings; it expands or reduces color information to clarify color differences, thereby facilitating the detection and observation of lesions. This article summarizes the characteristics of LCI and advances in LCI-related research in the upper gastrointestinal tract field.

Usefulness of the Kyoto Classification Score for Prediction of Current Helicobacter pylori Infection

Background/Aims: Based on the Kyoto classification of gastritis, mucosal atrophy, endoscopic intestinal metaplasia, fold enlargement, nodularity, and diffuse redness may be associated with gastric cancer and Helicobacter pylori (H. pylori) infection. In this study, we investigated the association between Kyoto scores based on the aforementioned five variables and current H. pylori infection.Materials and Methods: We reviewed medical records of consecutive patients who underwent endoscopic biopsies between January and June 2019. The study included 687 patients (370 and 317 patients with H. pylori-negative and -positive results, respectively). The Kyoto score was evaluated by the endoscopist who performed the test and was reconfirmed by another endoscopist. The total Kyoto score was analyzed using a receiver operating characteristic (ROC) curve for each score from 0 to 8. Multivariate analysis was used to determine the variables associated with H. pylori infection.Results: The maximum value of the Youden index (which reflects the ideal cut-off score of the Kyoto score on the ROC curve) was a Kyoto score of 2 points (Youden index 0.5905). Nodularity (OR 24.69, 95% CI 8.57~71.16, P<0.001) and diffuse redness (1 point: OR 18.29, 95% CI 10.29~32.52, P<0.001 and 2 points: OR 30.82, 95% CI 14.07~67.52, P<0.001) showed the highest OR on multivariate analysis.Conclusions: A Kyoto classification cut-off score of 2 points was suggestive of H. pylori infection, and mucosal nodularity and diffuse redness were most significantly associated with the risk of infection.

Risk factors for early gastric cancer: focus on Helicobacter pylori gastritis

Background: Gastric cancer is a global health problem, and the incidence and geographical distribution of different types of gastric cancer varies. Particularly, noncardiac gastric cancer is more prevalent in East Asia, Central and Eastern Europe, Latin America, and Africa. Infection with Helicobacter pylori, which was discovered in 1982, is a common cause of chronic gastritis, and the association between H. pylori infection and gastric adenocarcinoma is well established.Current Concepts: Gastric cancer is histologically divided into 2 types: intestinal and diffuse. H. pylori infection is considered as the main risk factor for the development of both types of gastric tumors. The most documented course of development of stomach cancer is following cellular metaplasia due to chronic inflammation, damage, and repair. Various molecular alterations caused by H. pylori are identified not only in gastric cancer but also in precancerous lesions. Recently, many studies have attempted to diagnose H. pylori gastritis and precancerous lesions using endoscopy.Discussion and Conclusion: Recent studies have shown that eradication therapy stabilizes or reduces the risk of developing gastric cancer. Therefore, the diagnosis and understanding of gastritis and precancerous lesions caused by H. pylori are the first step in the prevention of gastric cancer.

In situ Diagnosis of Helicobacter pylori Infection Using the Endoscopic Kyoto Scoring System

Background/Aims: This study aimed to investigate the possibility of in situ diagnosis of Helicobacter pylori (H. pylori) infection during endoscopic examination. The predictive infection value was estimated using the endoscopic Kyoto scoring system (EKSS), and specific endoscopic findings were evaluated for diagnosing H. pylori infection in H. pylori naïve patients and those with a eradication history.Materials and Methods: A total of 836 patients with H. pylori infection were analyzed. The state of the infection was predicted using the EKSS and specific endoscopic findings.Results: Patients were classified into two groups: the H. pylori naïve group and the group with a the bacterial eradication history. The area under the curve (AUC) on receiver operating characteristics analysis was 0.90 for EKSS in H. pylori naïve patients and 0.83 for the other group patients. For patients with open type atrophy and/or intestinal metaplasia, EKSS (24.4%; 95% CI, 12.4~0.3%) and regular arrangement of collecting venules (RAC) (46.3%; 95% CI, 30.7~62.9%) showed low specificities. Mucosal swelling (66.2%; 95% CI, 62.5~69.7%) and sticky mucus (80.5%; 95% CI, 74.8~85.2%) presented relatively high positive predictive values for H. pylori infection in naïve patients, whereas reflux esophagitis, hematin, red streak, and duodenitis exhibited high negative predictive values in patients with a H. pylori eradication history (98.0%; 95% CI, 96.4~99.1%).Conclusions: EKSS and RAC are excellent tools for predicting H. pylori infection. However, they have a limited role in patients with open type atrophy and/or intestinal metaplasia. Specific endoscopic findings could help predict the infection state.

Gastritis: The clinico-pathological spectrum

The inflammatory spectrum of gastric diseases includes different clinico-pathological entities, the etiology of which was recently established in the international Kyoto classification. A diagnosis of gastritis combines the information resulting form the gross examination (endoscopy) and histology (microscopy). It is important to consider the anatomical/functional heterogeneity of the gastric mucosa when obtaining representative mucosal biopsy samples. Gastritis includes self-limiting and non-self-limiting (long-standing) inflammatory diseases, and the latter are epidemiologically, biologically and clinically linked to the onset of gastric cancer (i.e. "inflammation-associated cancer"). Different biological models of inflammation-associated gastric oncogenesis have been proposed. Helicobacter pylori (H. pylori) gastritis is the most prevalent worldwide, and H. pylori is classified as a first-class carcinogen. On these bases, eradicating H. pylori is mandatory for the primary prevention of gastric cancer. Non-self-limiting gastritis may also be triggered by the immune-mediated destruction of gastric parietal cells, resulting in autoimmune gastritis. In both H. pylori-related and autoimmune gastritis, the non-self-limiting inflammation results in atrophy of the gastric mucosa, which is the main factor promoting gastric cancer. Long-term follow-up studies consistently demonstrate the prognostic impact of the histological staging of gastritis in gastric cancer secondary prevention strategies.

Deep learning for diagnosis of precancerous lesions in upper gastrointestinal endoscopy: A review

Upper gastrointestinal (GI) cancers are the leading cause of cancer-related deaths worldwide. Early identification of precancerous lesions has been shown to minimize the incidence of GI cancers and substantiate the vital role of screening endoscopy. However, unlike GI cancers, precancerous lesions in the upper GI tract can be subtle and difficult to detect. Artificial intelligence techniques, especially deep learning algorithms with convolutional neural networks, might help endoscopists identify the precancerous lesions and reduce interobserver variability. In this review, a systematic literature search was undertaken of the Web of Science, PubMed, Cochrane Library and Embase, with an emphasis on the deep learning-based diagnosis of precancerous lesions in the upper GI tract. The status of deep learning algorithms in upper GI precancerous lesions has been systematically summarized. The challenges and recommendations targeting this field are comprehensively analyzed for future research.

What Is New in Helicobacter pylori Diagnosis. An Overview

Helicobacter pylori infection remains one of the most prevalent infections worldwide, especially in low-resource countries, and the major risk factor for peptic ulcer and gastric cancer. The “test-and-treat” strategy is recommended by several guidelines and consensus. The choice of testing method is based on patient age, presence of alarm signs and/or symptoms, use of non-steroidal anti-inflammatory drugs, as well as local availability, test reliability, and cost. Culture is the gold standard to detect H. pylori and, possibly, to perform susceptibility testing, however, it requires upper endoscopy and dedicated labs. Recent advances in molecular biology have provided new strategies in detecting infection and antimicrobial resistance without invasive tests. In this review we attempt to offer a comprehensive panorama on the new diagnostic tools and their potential use in clinical settings, in order to accomplish specific recommendations.

Clinical Features of False-Negative Early Gastric Cancers: A Retrospective Study of Endoscopic Submucosal Dissection Cases

Background

We frequently encounter early gastric cancer (EGC) that could not be detected in the previous esophagogastroduodenoscopy even if the procedure was annually performed. However, little evidence exists regarding the characteristics of false-negative EGCs. Our aim was to reveal the clinical features of false-negative EGCs.

Methods

We retrospectively reviewed cases of endoscopic submucosal dissection (ESD) for EGCs in Fukuchiyama City Hospital between January 2013 and May 2019. False-negative EGCs were defined as EGCs within 3 years of negative endoscopy. We evaluated the clinical characteristics of false-negative and initially detected EGCs and the difference in the detected and last missed endoscopy in false-negative EGCs. The miss rates of false-negative EGCs were compared between trainees (nonboard-certified endoscopists) and experienced endoscopists (board-certified endoscopists); thereafter, the characteristics of false-negative EGCs missed by trainees were investigated.

Results

Of 219 cases, 119 were classified as false-negative EGCs. False-negative EGCs were characterized as smaller lesions, which presented with normal color or gastritis-like appearance, and were diagnosed after ESD and H. pylori eradication (P < 0.01). The rate of trainees in the last missed endoscopy was significantly higher than that in the detected endoscopy. The miss rate of false-negative EGC by trainees was higher than that of experienced endoscopists but not significantly different (0.70% vs. 0.57%, P = 0.08). The false-negative EGCs missed by trainees were characterized as reddish or well-differentiated lesions, which were located in the lower or lesser curvature of the stomach (P < 0.05).

Conclusion

The characteristics of false-negative EGCs were similar to those of H. pylori-eradicated EGC. Procedures with shortened examination time and those performed by trainees were risk factors of missing false-negative EGCs. Trainees should pay attention to reddish or well-differentiated EGCs located in the lower or lesser curvature of the stomach.

The endoscopic predictors of Helicobacter pylori status: a meta-analysis of diagnostic performance

Objective:

The endoscopic findings associated with Helicobacter pylori–naïve status, current infection or past infection are an area of ongoing interest. Previous studies have investigated parameters with a potential diagnostic value. The aim of this study was to perform meta-analysis of the available literature to validate the diagnostic accuracy of mucosal features proposed in the Kyoto classification.

Data sources:

The databases of MEDLINE and Embase, clinicalTrials.gov and the Cochrane Library were systematically searched for relevant studies from October 1999 to October 2019.

Methods:

A bivariate random effects model was used to produce pooled diagnostic accuracy calculations for each of the studied endoscopic findings. Diagnostic odds ratios and sensitivity and specificity characteristics were calculated to identify significant predictors of H pylori status.

Results:

Meta-analysis included 4380 patients in 15 studies. The most significant predictor of an H pylori-naïve status was a regular arrangement of collecting venules (diagnostic odds ratio 55.0, sensitivity 78.3%, specificity 93.8%). Predictors of active H pylori infection were mucosal oedema (18.1, 63.7%, 91.1%) and diffuse redness (14.4, 66.5%, 89.0%). Map-like redness had high specificity for previous H pylori eradication (99.0%), but poor specificity (13.0%).

Conclusion:

The regular arrangement of collecting venules, mucosal oedema, diffuse redness and map-like redness are important endoscopic findings for determining H pylori status. This meta-analysis provides a tentative basis for developing future endoscopic classification systems.

The role of linked color imaging in endoscopic diagnosis of Helicobacter pylori associated gastritis

OBJECTIVE

Linked color imaging (LCI), a novel image-enhanced endoscopy, can make it easy to recognize differences in mucosal color. It may be helpful for diagnosing H. pylori associated gastritis and H. pylori infection status. We investigated whether LCI could improve the diagnostic accuracy of H. pylori associated gastritis.

MATERIALS AND METHODS

Upper endoscopy was performed for 100 patients using white light imaging (WLI) and LCI. During the exam, endoscopic video was recorded. It was then analyzed by four expert endoscopists. They reviewed these videos for endoscopic diagnosis of atrophic gastritis, metaplastic gastritis, nodular gastritis and H. pylori infection. Tissue biopsies with rapid urease test were done to confirm H. pylori infection status and intestinal metaplasia.

RESULTS

Kappa values for the inter-observer variability among the four endoscopists were fair to moderate under WLI and fair to good under LCI. Sensitivity, specificity, positive predictive value and negative predictive value for diagnosing H. pylori infection using WLI were 32.4%, 93.3%, 85.2% and 53.6%, respectively, while those for LCI were 57.4%, 91.3%, 88.7% and 64.3%, respectively. Total diagnostic accuracies for diagnosing H. pylori infection using WLI/LCI were 70.8%/78.8%. The accuracy and sensitivity of LCI for diagnosing H. pylori infection were significantly higher than those of WLI (p < .001 for both). However, there were no significant differences in the accuracy, sensitivity or specificity for diagnosing metaplastic gastritis between LCI and WLI.

CONCLUSIONS

LCI has better diagnostic accuracy for H. pylori infection status than WLI. Clinical trial registration number: KCT0003674.

Helicobacter pylori Gastritis in Children-The Link between Endoscopy and Histology

Background: The management of Helicobacter pylori (H. pylori) infection raises important challenges, still being the most common chronic infection worldwide in all age groups. In high-prevalence regions, paediatric patients need a specific focus, as the acquisition of the infection takes place in childhood. The objective of this study was to analyze the endoscopic and histopathologic changes of the gastric mucosa in H. pylori infected children. Material and Methods: A retrospective study was performed on consecutive paediatric patients, ranging from 0 to 18 years of age, who underwent an upper gastrointestinal endoscopy (UGE) for a period of 5 years, regardless of their symptomatology. Endoscopy reports and histological slides were reviewed and clinical, endoscopic, and histologic data were recorded. Results: A total of 248 patients were included in the study, 82 (33.06%) of them being H. pylori infected. There was no difference in age and symptoms between the infected and noninfected group. A significant association was found between the H. pylori infection and histopathological parameters such as acute and chronic inflammatory infiltrate. The bacterial load influences the intensity of inflammation (p < 0.001). The chronic inflammation was predominant, only 23.2% of the patients displayed acute inflammation (p < 0.0001). The topographic distribution of inflammation was dominated by pangastritis (p = 0.04) with 58.6% of the patients presenting similar degrees of inflammation both in the antrum and corpus. Conclusion: Endoscopic features such as nodularity of the antral mucosa (p < 0.05) along with histological findings as lymphoid follicles (p < 0.05) are suggestive of H. pylori infection. However, the concordance between the endoscopic and histological diagnosis is still far from perfect (Cohen’s k coefficient = 0.42), maintaining the need for an invasive approach in children.

Review: Diagnosis of Helicobacter pylori infection

Endoscopic imaging of the stomach is improving. In addition to narrow band imaging, other methods, for example, blue light imaging and linked color imaging, are now available and can be combined with artificial intelligence systems to obtain information on the gastric mucosa and detect early gastric cancer. Immunohistochemistry is only recommended as an ancillary stain in case of chronic active gastritis without Helicobacter pylori detection by standard staining, and recommendations to exclude false negative H. pylori results have been made. Molecular methods using real-time PCR, droplet digital PCR, or amplification refractory mutation system PCR have shown a high accuracy, both for detecting H. pylori and for clarithromycin susceptibility testing, and can now be used in clinical practice for targeted therapy. The most reliable non-invasive test remains the ¹³ C-urea breath test. Large data sets show that DOB values are higher in women and that the cut-off for positivity could be decreased to 2.74 DOB. Stool antigen tests using monoclonal antibodies are widely used and may be a good alternative to UBT, particularly in countries with a high prevalence of H. pylori infection. Attempts to improve serology by looking at specific immunodominant antigens to distinguish current and past infection have been made. The interest of Gastropanel^® which also tests pepsinogen levels was confirmed.