Helicobacter pylori infection in subjects negative for high titer serum antibody

Characteristic endoscopic findings in Helicobacter pylori diagnosis in clinical practice

INTRODUCTION

Helicobacter pylori is a major risk factor for gastric cancer. In addition to eradication therapy, early-phase detection of gastric cancer through screening programs using high-vision endoscopy is also widely known to reduce mortality. Although European and US guidelines recommend evaluation of atrophy and intestinal metaplasia by high-vision endoscopy and pathological findings, the guideline used in Japan - the Kyoto classification of gastritis - is based on endoscopic evaluation, and recommends the grading of risk factors. This system requires classification into three endoscopic groups: H. pylori-negative, previous H. pylori infection (inactive gastritis), and current H. pylori infection (active gastritis). Major endoscopic findings in active gastritis are diffuse redness, enlarged folds, nodularity, mucosal swelling, and sticky mucus, while those in H pylori-related gastritis - irrespective of active or inactive status - are atrophy, intestinal metaplasia, and xanthoma.

AREAS COVERED

This review describes the endoscopic characteristics of current H. pylori infection, and how characteristic endoscopic findings should be evaluated.

EXPERT OPINION

Although the correct evaluation of endoscopic findings related to H. pylori remains necessary, if findings of possible infection are observed, it is important to diagnose infection by detection methods with high sensitivity and specificity, including the stool antigen test and urea breath test.

Predicting Helicobacter pylori infection from endoscopic features

BACKGROUND

Helicobacter pylori infection, prevalent in more than half of the global population, is associated with various gastrointestinal diseases, including peptic ulcers and gastric cancer. The effectiveness of early diagnosis and treatment in preventing gastric cancer highlights the need for improved diagnostic methods. This study aimed to develop a simple scoring system based on endoscopic findings to predict H. pylori infection.

METHODS

A retrospective analysis was conducted on 1,007 patients who underwent upper gastrointestinal endoscopy at Asan Medical Center from January 2019 to December 2021. Exclusion criteria included prior H. pylori treatment, gastric surgery, or gastric malignancies. Diagnostic techniques included rapid urease and 13C-urea breath tests, H. pylori culture, and assessment of endoscopic features following the Kyoto gastritis classification. A new scoring system based on endoscopic findings including regular arrangement of collecting venules (RAC), nodularity, and diffuse or spotty redness was developed for predicting H. pylori infection, utilizing logistic regression analysis in the development set.

RESULTS

The scoring system demonstrated high predictive accuracy for H. pylori infection in the validation set. Scores of 2 and 3 were associated with 96% and 99% infection risk, respectively. Additionally, there was a higher prevalence of diffuse redness and sticky mucus in cases where the initial H. pylori eradication treatment failed.

CONCLUSION

Our scoring system showed potential for improving diagnostic accuracy in H. pylori infection. H. pylori testing should be considered upon spotty redness, diffuse redness, nodularity, and RAC absence on endoscopic findings as determined by the predictive scoring system.

Establishment of a modified Kyoto classification scoring model and its significance in the diagnosis of Helicobacter pylori current infection

BACKGROUND AND AIMS

We aimed to establish a modified model of the Kyoto classification score and verify its accuracy for predicting Helicobacter pylori (HP) infection during endoscopy.

METHODS

Patients who underwent gastroscopy from June 2020 to March 2021 were included in this study. Atrophy, intestinal metaplasia, hypertrophy of the gastric fold, nodularity, diffuse redness, sticky mucus, spotty redness, xanthoma, map-like redness, fundic gland polyp, and regular arrangement of collecting venules (RAC) were recorded according to the Kyoto classification of gastritis. The HP infection status of participants was determined by a ¹³C breath test, anti-HP antibody, and histopathologic hematoxylin and eosin staining. The modified Kyoto classification scoring model was established based on univariate analysis and logistic regression analysis. The modified scoring model was used to judge the status of HP infection in patients undergoing gastroscopy from July to September 2021 and to evaluate the accuracy of the prediction.

RESULTS

Of 667 participants in the derivation dataset, 326 cases had HP infection and 341 cases did not. Atrophy, hypertrophy of the gastric fold, nodularity, diffuse redness, sticky mucus, and spotty redness were associated with HP current infection. Thus, a new scoring model, termed the modified Kyoto classification scoring model, was constructed that included atrophy, hypertrophy of the gastric fold, nodularity, diffuse redness, sticky mucus, spotty redness, fundic gland polyp, and RAC as indicators. To test the model, 808 subjects, including 251 HP-positive patients, comprised the validation dataset.

CONCLUSIONS

The modified Kyoto classification scoring model improved the accuracy of endoscopic determination of HP current infection and has clinical application potential in the Chinese population.

Performing the ABC Method Twice for Gastric Cancer Risk Stratification: A Retrospective Study Based on Data from a Large-Scale Screening Facility

The ABC method is a classification method used for stratifying the risk of gastric cancer. However, whether the ABC method should be performed only once or multiple times throughout an individual’s lifetime remains unclear. Therefore, this study aimed to analyze whether performing ABC screening twice in a lifetime is useful. We retrospectively analyzed the data of individuals who participated in health checkups in 2010 and 2015. We collected data on patient characteristics, pepsinogen levels, anti-Helicobacter pylori antibody titers, and the presence of gastric cancer. Overall, 7129 participants without a history of H. pylori eradication were included in this study. The participants’ average age in 2010 was 48.4 ± 8.3 years, and 58.1% were male. In addition, 11 and 20 cases of new H. pylori infection (0.15%) and spontaneous eradication (0.28%), respectively, were recorded. No significant difference was found in the incidence of gastric cancer between participants who underwent the ABC method once and those who underwent it twice (Group A: 0.16% vs. 0.16%; Group B: 0.47% vs. 0.39%; and Group C + D: 1.97% vs. 1.82%). Therefore, performing the ABC method twice, 5 years apart, does not significantly improve gastric cancer risk stratification.

Focusing on Helicobacter pylori infection in the elderly

As a confirmed carcinogen, Helicobacter pylori (H. pylori) is the main cause of inflammatory diseases of the upper digestive tract and even gastric cancer. There is a high prevalence of H. pylori infection among the elderly population, which may cause adverse clinical outcomes. Particularly noteworthy is that guidelines or expert consensus presently available on H. pylori infection overlook the management of the elderly population as a special group. A brief overview of H. pylori in the elderly is as follows. The detection of H. pylori infection can be divided into invasive and non-invasive techniques, and each technique has its advantages and shortcomings. There may be more side effects associated with eradication treatment in elderly individuals, especially for the frail population. Physical conditions and risk-benefit assessments of the elderly should be considered when selecting therapeutic strategies for H. pylori eradication. Unless there are competing factors, elderly patients should receive H. pylori eradication regimens to finally reduce the formation of gastric cancer. In this review, we summarize the latest understanding of H. pylori in the elderly population to provide effective managements and treatment measures.

Kyoto classification of gastritis, virtual chromoendoscopy and artificial intelligence: Where are we going? What do we need?

Chronic gastritis (CG) is a widespread and frequent disease, mainly caused by Helicobacter pylori infection, which is associated with an increased risk of gastric cancer. Virtual chromoendoscopy improves the endoscopic diagnostic efficacy, which is essential to establish the most appropriate therapy and to enable cancer prevention. Artificial intelligence provides algorithms for the diagnosis of gastritis and, in particular, early gastric cancer, but it is not yet used in practice. Thus, technological innovation, through image resolution and processing, optimizes the diagnosis and management of CG and gastric cancer. The endoscopic Kyoto classification of gastritis improves the diagnosis and management of this disease, but through the analysis of the most recent literature, new algorithms can be proposed.

Kyoto classification of gastritis: Advances and future perspectives in endoscopic diagnosis of gastritis

This editorial provides an update of the recent evidence on the endoscopy-based Kyoto classification of gastritis, clarifying the shortcomings of the Kyoto classification, and providing prospects for future research, with particular focus on the histological subtypes of gastric cancer (GC) and Helicobacter pylori (H. pylori) infection status. The total Kyoto score is designed to express GC risk on a score ranging from 0 to 8, based on the following five endoscopic findings: Atrophy, intestinal metaplasia (IM), enlarged folds (EF), nodularity, and diffuse redness (DR). The total Kyoto score reflects H. pylori status as follows: 0, ≥ 2, and ≥ 4 indicate a normal stomach, H. pylori-infected gastritis, and gastritis at risk for GC, respectively. Regular arrangement of collecting venules (RAC) predicts non-infection; EF, nodularity, and DR predict current infection; map-like redness (MLR) predicts past infection; and atrophy and IM predict current or past infection. Atrophy, IM, and EF all increase the incidence of H. pylori-infected GC. MLR is a specific risk factor for H. pylori-eradicated GC, while RAC results in less GC. Diffuse-type GC can be induced by active inflammation, which presents as EF, nodularity, and atrophy on endoscopy, as well as neutrophil and mononuclear cell infiltration on histology. In contrast, intestinal-type GC develops via atrophy and IM, and is consistent between endoscopy and histology. However, this GC risk-scoring design needs to be improved.

Negative-High Titer of Helicobacter pylori Antibody and Lipid Profiles

Background. Helicobacter pylori (HP) is a causative factor for several gastrointestinal diseases. A HP seropositive antibody titer (i.e., ≥10 U/mL), a threshold indicating an HP infection, is known to be associated with changes in lipid metabolism. There is evidence that HP infection can be found in some individuals with HP antibody titer of between 3 and 9.9 U/mL (termed as “negative-high titer”). However, it is unknown about the relationship between HP negative-high titer and lipid metabolism. The present study aimed to quantify the association between HP negative-high antibody titer and lipid profiles. Materials and Methods. We surveyed 2,478 people who underwent a Ningen Dock examination and had serological HP antibody data, from May 2016 to December 2020 at National Center for Global Health and Medicine, Tokyo, Japan. Multiple regression models were used to quantify the association between HP antibody titer and serum lipid levels. Results. The adjusted odds ratio (95% confidence interval [CI]) for dyslipidemia in HP negative-high and positive titer was 1.24 (0.96, 1.79) and 1.36 (1.10, 1.68), respectively, compared with HP negative-low titer; $p$ trend =0.005. The adjusted mean (95% CI) of high-density lipoprotein cholesterol (HDL-C) in HP negative-low, negative-high, and positive titer was 58.78 (57.86–59.71), 55.30 (53.70–56.91), and 53.76 (52.90–54.63) mg/dL, respectively; $p$ trend <0.001. Higher HP antibody titers were also associated with higher ratio of low-density lipoprotein cholesterol (LDL-C) to HDL-C, but not triglycerides, or total cholesterols. Conclusion. The present cross-sectional study suggests that a HP negative-high antibody titer may be associated with dyslipidemia, HDL-C, and LDL-C to HDL-C ratio among Japanese Ningen Dock’s participants.

Innate Immunity Crosstalk with Helicobacter pylori: Pattern Recognition Receptors and Cellular Responses

Helicobacter pylori is one of the most successful gastric pathogens that has co-existed with human for centuries. H. pylori is recognized by the host immune system through human pattern recognition receptors (PRRs), such as toll-like receptors (TLRs), C-type lectin like receptors (CLRs), NOD-like receptors (NLRs), and RIG-I-like receptors (RLRs), which activate downstream signaling pathways. Following bacterial recognition, the first responders of the innate immune system, including neutrophils, macrophages, and dendritic cells, eradicate the bacteria through phagocytic and inflammatory reaction. This review provides current understanding of the interaction between the innate arm of host immunity and H. pylori, by summarizing H. pylori recognition by PRRs, and the subsequent signaling pathway activation in host innate immune cells.

Consistency between the endoscopic Kyoto classification and pathological updated Sydney system for gastritis: A cross-sectional study

BACKGROUND

Two methods are used to evaluate gastritis: the updated Sydney system (USS) with pathology and Kyoto classification, a new endoscopy-based diagnostic criterion for which evidence is accumulating. However, the consistency of their results is unclear. This study investigated the consistency of their results.

METHODS

Patients who underwent esophagogastroduodenoscopy and were evaluated for Helicobacter pylori infection for the first time were eligible. The association between corpus and antral USS scores (neutrophil activity, chronic inflammation, atrophy, and intestinal metaplasia) and Kyoto classification scores (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness) was assessed.

RESULTS

Seven-hundred-seventeen patients (mean age, 49.2 years; female sex, 57.9%; 450 H. pylori-positive and 267 H. pylori-negative patients) were enrolled. All endoscopic gastritis cases in the Kyoto classification were associated with high corpus and antral USS scores for neutrophil activity and chronic inflammation. A subanalysis was performed for H. pylori-positive patients. Regarding atrophy and intestinal metaplasia, endoscopic findings were associated with USS scores. Enlarged folds, nodularity, and diffuse redness were associated with high corpus USS scores for neutrophil activity and chronic inflammation, but with low antral USS scores for atrophy and intestinal metaplasia. The Kyoto classification scores were also associated with the pathological topographic distribution of neutrophil activity and intestinal metaplasia.

CONCLUSIONS

Among H. pylori-positive individuals, endoscopic and pathological diagnoses were consistent with atrophy and intestinal metaplasia. Enlarged folds, nodularity, and diffuse redness were associated with pathological inflammation (neutrophil activity and chronic inflammation) of the corpus; however, they were inversely associated with pathological atrophy and intestinal metaplasia. The endoscopy-based Kyoto classification of gastritis partially reflects pathology.

The Association of Trefoil Factors with Gastric Cancer and Premalignant Lesions: A Cross-sectional Population-based Cohort Study

BACKGROUND

A lack of research on the association of trefoil factors (TFFs) with gastric cancer (GC) and premalignant lesions (PMLs) in the general populations is an important obstacle to the application of TFFs for GC screening. We aimed to analyze the association of TFFs with GC and PMLs in a general population.

METHODS

We evaluated 3,986 adults residing in Wuwei, China. We collected baseline characteristics and GC risk factors, including TFFs, endoscopic diagnosis, and pathological information. Three logistic regression models were generated to analyze the association between TFFs and GC, as well as PMLs. Adjusted odds ratio (OR) and 95% confidence intervals (95% CI) were calculated to determine the strength of association.

RESULTS

Compared with pepsinogen (PG) and anti-Helicobacter pylori immunoglobulin G antibody (Hp-IgG), TFFs had significant association with GC and PMLs after adjusting for biomarkers and risk factors (P < 0.05). The ORs [95% CI] for TFF1 (1.67 [1.27-2.20]), TFF2 (2.66 [2.01-3.51]), and TFF3 (1.32 [1.00-1.74]) were larger than the ORs for PGI (0.79 [0.61-1.03]), PGI/II (1.00 [0.76-1.31]) and Hp-IgG (0.99 [0.73-1.35]) in the GC group. In intestinal metaplasia (IM) group, not only the TFF3 serum level was the highest, but also the OR (1.92 [1.64-2.25]) was the highest.

CONCLUSIONS

Trefoil factor were associated with risk of GC and PMLs.

IMPACT

Serum TFFs can improve the screening of high-risk populations for GC.

The Optimal Cut-off of the Latex Immunoassay (LZ Test) for Helicobacter pylori Infection Based on the Stool Antigen Test and Helicobacter pylori-associated Gastritis

Objective Helicobacter pylori antibody kits using the latex immunoassay (LIA) are widely used in Japan. However, the optimal cut-off of the LIA remains unclear. This study clarified the optimal cut-off of the LIA for assessing the current infection status of patients (currently infected, never infected, spontaneously eradicated) in clinical practice. Methods In total, 482 subjects with no history of H. pylori eradication therapy who underwent a medical examination at our hospital were enrolled. The infection status was ascertained using a stool antigen test, and the endoscopic findings of H. pylori-associated gastritis. H. pylori antibody levels were measured using the LIA. Results In total, 414, 38, and 30 subjects were categorized into the never-infected, currently infected, and spontaneously eradicated groups. The optimal cut-off based on receiver operating characteristic curve analysis was 4 U/mL, whereas the area under the curve, sensitivity, and specificity for differentiating never-infected and currently infected subjects were 0.95, 92.1%, and 94.7%, respectively. When applying the cut-off of 4 U/mL to the judgment of current infection in all subjects, the sensitivity and specificity were 92.1% and 92.6%, respectively. Conclusion Our findings suggest that 4 U/mL was the optimal cut-off for differentiating current infection from no prior infection, and the value may be stable because of the exclusion of subjects with spontaneous eradication. The cut-off may be useful in initial screening for current H. pylori infection.

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.

Prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings of non-Helicobacter pylori Helicobacter infection: A study of 50 cases at a single facility in Japan

BACKGROUND AND AIM

There are only a few reports of non-Helicobacter pylori Helicobacter (NHPH) gastritis in Japanese patients. We aimed to examine its prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings based on 50 patients encountered in one facility.

MATERIALS AND METHODS

Subjects were all patients who had undergone gastric mucosal biopsy endoscopically at Kenwakai Hospital for approximately 10 years. NHPH infection was diagnosed by microscopic findings of Giemsa staining performed on all specimens. PCR analysis of urease genes was performed to detect and identify NHPH, when informed consent was obtained. Helicobacter pylori-diagnostic tests were also performed. NHPH-infected patients were questioned about symptoms and animal contact.

RESULTS

NHPH gastritis was found in 50 of 3847 patients (1.30%). The percentage increased to 3.35% (30 of 896 patients) in the latter 2 years and 4 months with increasing recognition of its characteristic endoscopic findings by endoscopists. PCR analysis, performed in 30 patients, detected NHPH in 28 patients: 26 as Helicobacter suis and 2 as Helicobacter heilmanii/Helicobacter ailurogastricus. Helicobacter pylori-diagnostic tests were almost negative. However, anti-H. pylori antibody showed high-negative titer (3.0-9.9 U/ml) in 12. Of 50 patients (consisting of 49 men and 1 woman), almost all were asymptomatic, and 25 were keeping pets. Regarding EGD findings, in all 50 patients, "crack-like mucosa" and/or nodular gastritis was noted in gastric antrum, and regular arrangement of collecting venules (RAC) was noted in gastric corpus. None of the patients infected with NHPH were co-infected with H. pylori.

CONCLUSIONS

The prevalence was finally estimated to be approximately 3.35%. Helicobacter suis was the most common NHPH species. "Crack-like mucosa" and/or nodular gastritis in gastric antrum, RAC in gastric corpus, and H. pylori-negativity by H. pylori-diagnostic tests especially containing a high-negative titer of anti-H. pylori antibody may indicate NHPH infection.

Diagnosis of Helicobacter pylori Infection and Recent Advances

BACKGROUND

Helicobacter pylori (H. pylori) infects approximately 50% of the world population. Its infection is associated with gastropathies, extra-gastric digestive diseases, and diseases of other systems. There is a canonical process from acute-on-chronic inflammation, chronic atrophic gastritis (CAG), intestinal metaplasia (IM), dysplasia, and intraepithelial neoplasia, eventually to gastric cancer (GC). H. pylori eradication abolishes the inflammatory response and early treatment prevents the progression to preneoplastic lesions.

METHODS

the test-and-treat strategy, endoscopy-based strategy, and screen-and-treat strategy are recommended to prevent GC based on risk stratification, prevalence, and patients' clinical manifestations and conditions. Challenges contain false-negative results, increasing antibiotic resistance, decreasing eradication rate, and poor retesting rate. Present diagnosis methods are mainly based on invasive endoscopy and noninvasive laboratory testing.

RESULTS

to improve the accuracy and effectiveness and reduce the missed diagnosis, some advances were achieved including newer imaging techniques (such as image-enhanced endoscopy (IEE), artificial intelligence (AI) technology, and quantitative real-time polymerase chain reaction (qPCR) and digital PCR (dPCR).

CONCLUSION

in the article, we summarized the diagnosis methods of H. pylori infection and recent advances, further finding out the opportunities in challenges.

Incidence of Infection among Subjects with Helicobacter pylori Seroconversion

Background/Aims

Helicobacter pylori (H. pylori) seroconversion may occur during screening for gastric cancer. Our study aimed to assess the number of seroconverted subjects with H. pylori and their results in follow-up tests.

Methods

Data were consecutively collected on subjects who were H. pylori-seronegative and presented for gastric cancer screening. Subjects who were followed up using the same serology test and pepsinogen (PG) assays on the day of endoscopy were included in the study.

Results

During the follow-up of 57.7 ± 21.4 months, 61 (15.0%) of 407 seronegative subjects showed seroconversion. H. pylori infection was detected in six (9.8%) of 61 seroconverted subjects. A diffuse red fundal appearance, with a significant increase in the Kyoto classification scores for gastritis, was observed in the infected subjects (p<0.001). Compared to the false-seropositive subjects, infected subjects showed higher serology titers (p<0.001) and PG II levels (p<0.001), and lower PG I/II ratios (p=0.002), in the follow-up tests.

Conclusions

Seroconversion occurred in 3.3% of seronegative subjects per year; however, only 9.8% had H. pylori infection. The majority (90.2%) of the seroconverted subjects showed false seropositivity without significant changes in the follow-up test results. The diffuse red fundal appearance could be an indicator of H. pylori infection.

Risk Factors for Prolonged Hospital Stay after Endoscopy

Background/Aims

The recovery room used after endoscopy has limited capacity, and an efficient flow of the endoscopy unit is desired. We investigated the duration of hospital stay after endoscopy and the risk factors for prolonged hospital stay among outpatients.

Methods

We retrospectively studied consecutive patients who underwent esophagogastroduodenoscopy or colonoscopy at the Toyoshima Endoscopy Clinic. We collected data on age, sex, body weight, midazolam and pethidine dosage, respiratory depression during endoscopy, and duration of hospital stay after endoscopy (scope out to check out). Risk factors for prolonged hospital stay (>100 minutes) were identified using multiple logistic regression analysis.

Results

We enrolled 3,898 patients, including 3,517 (90.2%) patients tested under sedation and 381 (9.8%) patients tested without sedation. Overall, 442 (11.3%) patients had prolonged stay (>100 min). The mean time difference between sedation group and non-sedation group was 44.2 minutes for esophagogastroduodenoscopy and 39.1 minutes for colonoscopy. Age (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.014−1.036), female sex (OR, 1.657; 95% CI, 1.220−2.249), and midazolam dose (OR, 1.019; 95% CI, 1.013−1.026) were independently associated with prolonged hospital stay after esophagogastroduodenoscopy, with similar results for colonoscopy.

Conclusions

Old age, female sex, and midazolam dose were independent risk factors for prolonged hospital stay after endoscopy.

Prevalence of Barrett's Epithelium Shown by Endoscopic Observations with Linked Color Imaging in Subjects with Different H. pylori Infection Statuses

Objective This study was conducted to clarify the prevalence of short segment Barrett's esophagus (SSBE) using endoscopic observations with linked color imaging (LCI). In addition, the relationship between the presence of Barrett's epithelium (BE) and the status of H. pylori infection was investigated. Methods The study subjects were 3,353 individuals (2,186 men, 1,167 women; mean age 55.2±9.4 years old) whose status of H. pylori infection had been determined. An endoscopic observation using LCI was performed to examine the distal margin of palisade vessels and confirm the area of BE. The prevalence of BE ≥5 mm in length was investigated. Results BE was diagnosed in 1,884 (56.2%) subjects, with lengths of <10, 10-19, 20-29, and ≥30 mm found in 1,005, 851, 27, and 1, respectively. Its prevalence in H. pylori-negative, H. pylori-positive, and post-eradicated subjects was 41.7%, 64.4%, and 69.9%, respectively (p<0.001). The duration since successful eradication of H. pylori did not affect the prevalence of BE. The degree of gastric mucosal atrophy was higher in cases with BE (p<0.001), although negativity for H. pylori infection and mild gastric mucosal atrophy were significant factors for the development of longer BE. Conclusion A high prevalence of SSBE was noted when LCI was used to determine the area of BE, as the distal end of the palisade vessels was easily visualized. Negativity for H. pylori infection and mild gastric mucosal atrophy were not correlated with SSBE prevalence.

A single nucleotide polymorphism in Prostate Stem Cell Antigen is associated with endoscopic grading in Kyoto classification of gastritis

The risk allele of a single nucleotide polymorphism (SNP) rs2294008 in the Prostate stem cell antigen (PSCA) gene is strongly associated with gastric cancer. Although the Kyoto classification score is believed to be an indicator of gastric cancer risk, it lacks supporting genetic evidence. We investigated the effect of this risk allele of PSCA SNP on the Kyoto score. Participants without a history of gastric cancer or Helicobacter pylori (H. pylori) eradication underwent esophagogastroduodenoscopy, H. pylori evaluation, and SNP genotyping. The Kyoto score is the sum of scores obtained from endoscopy-based atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness. The Kyoto score is novel in the light of scoring for gastritis. A total of 323 patients were enrolled (number of individuals with genotype CC: 52; CT: 140; TT: 131, average age: 50.1 years, male: 50.8%). The patient baseline characteristics including age, sex, body mass index, smoking, drinking, family history of gastric cancer, and H. pylori status had no association with PSCA SNP. The Kyoto score was higher in T (CT or TT genotype; risk allele) carriers than in CC carriers. Atrophy, enlarged folds, and diffuse redness scores were higher in T allele carriers (risk allele) than in CC genotype individuals. In multivariate analysis, the Kyoto score was independently associated with PSCA SNP (OR: 1.30, p = 0.012). Thus, the Kyoto score was associated with a genetic predisposition.

Utility of Kyoto Classification of Gastritis in subjects with a high-negative titer of anti-Helicobacter pylori antibody during a medical check-up

Subjects with a high-negative titer (3-9.9 U/ml) of serum anti-Helicobacter pylori (H. pylori) antibody represent a heterogeneous group of currently H. pylori-infected, H. pylori-uninfected, and previously H. pylori-infected cases. We investigated the characteristics of subjects with a high-negative titer during a medical check-up and the utility of H. pylori infection score, the sum of scores of endoscopic findings based on the Kyoto Classification of Gastritis, for diagnosing H. pylori infection. Subjects with ¹³C-urea breath test-positive or H. pylori stool antigen test-positive were diagnosed as currently H. pylori-infected. Although around half of subjects with a high-negative titer were after eradication therapy (48.6%), currently H. pylori-infected were considerably confirmed (11.7%). H. pylori infection score showed a high value of area under the receiver operating characteristic curve [0.92; 95% confidence interval (CI), 0.84-1.00] with the most suitable cut-off value of 1.0 (sensitivity: 0.92; specificity: 0.90). Multivariate logistic regression analysis revealed that H. pylori infection score was an independent factor associated with increased prevalence of H. pylori infection (odds ratio, 9.53; 95% CI, 2.64-34.40; p<0.001). Currently H. pylori-infected subjects were considerably included among the subjects with a high-negative titer, and the Kyoto Classification of Gastritis was useful to predict current H. pylori infection.

Serum Anti-Helicobacter pylori IgG Antibody Titer in H. pylori-negative Cases with a Different Gastric Mucosal Atrophy Status

Objective This retrospective study was performed to investigate the anti-Helicobacter pylori IgG antibody serum titers in H. pylori-negative subjects with different degrees of gastric mucosal atrophy including C0 grade atrophy. Methods The absence of H. pylori infection was determined based on both negative serum anti-H. pylori IgG antibody test findings and no endoscopic evidence of that infection. Cases negative for the antibody and with positive endoscopic findings of H. pylori infection were defined as H. pylori-positive. The serum anti-H. pylori IgG antibody titers were analyzed in H. pylori-negative (n=1,087), -positive (n=69), and post-eradicated (n=278) subjects. Results The serum antibody titer in subjects with H. pylori-positive endoscopy findings was significantly higher than that in H. pylori-negative subjects, even when the serum titer indicated a negative result. In addition, the anti-H. pylori IgG antibody serum titer was higher in H. pylori-negative subjects with a greater degree of gastric mucosal atrophy. In a comparison between H. pylori-negative C0 and C1 gastric mucosal atrophy cases, the antibody serum titer in those classified as C0 was significantly lower. An analysis of H. pylori post-eradicated cases showed that the serum antibody titer decreased over time after successful eradication. Conclusion The disappearance of H. pylori infection in H. pylori-negative individuals may occur later in those with a greater degree of gastric mucosal atrophy. The serum antibody titer difference between the H. pylori-negative C0 and C1 groups might have been caused by the differences in distribution between H. pylori-uninfected subjects and those in whom the infection had disappeared, thus additional investigation is needed to clarify the significance of gastric mucosal classification including the C0 grade.

Clinical features of cardiac nodularity-like appearance induced by Helicobacter pylori infection

BACKGROUND

We have previously reported that Helicobacter pylori (H. pylori)-associated nodular gastritis could occur in both the antrum and the cardia. Cardiac nodularity-like appearance (hereafter, called as cardiac nodularity) had a high predictive accuracy for the diagnosis of H. pylori infection. In the previous study, we included only the patients who were evaluated for H. pylori infection for the first time, and excluded patients with a history of eradication. Therefore, the prevalence and clinical features of cardiac nodularity remains unknown.

AIM

To perform this cross-sectional study to explore the characteristics of cardiac nodularity.

METHODS

Consecutive patients who underwent esophagogastroduodenoscopy between May, 2017 and August, 2019 in the Toyoshima Endoscopy Clinic were enrolled in this study. We included H. pylori-negative, H. pylori-positive, and H. pylori-eradicated patients, and excluded patients with unclear H. pylori status and eradication failure. H. pylori infection was diagnosed according to serum anti-H. pylori antibody and the urea breath test or histology. Cardiac nodularity was defined as a miliary nodular appearance or the presence of scattered whitish circular small colorations within 2 cm of the esophagogastric junction. Nodularity was visualized as whitish in the narrow-band imaging mode. We collected data on the patients’ baseline characteristics.

RESULTS

A total of 1078 patients were finally included. Among H. pylori-negative patients, cardiac nodularity and antral nodularity were recognized in 0.14% each. Among H. pylori-positive patients, cardiac nodularity and antral nodularity were recognized in 54.5% and 29.5%, respectively. Among H. pylori-eradicated patients, cardiac nodularity and antral nodularity were recognized in 4.5% and 0.6%, respectively. The frequency of cardiac nodularity was significantly higher than that of antral nodularity in H. pylori-positive and -eradicated patients. The frequencies of cardiac nodularity and antral nodularity in H. pylori-eradicated patients were significantly lower than those in H. pylori-positive patients (P < 0.001). The patients with cardiac nodularity were significantly younger than those without cardiac nodularity (P = 0.0013). Intestinal metaplasia score of the patients with cardiac nodularity were significantly lower than those without cardiac nodularity (P = 0.0216). Among H. pylori-eradicated patients, the patients with cardiac nodularity underwent eradication significantly more recently compared with those without cardiac nodularity (P < 0.0001).

CONCLUSION

This report outlines the prevalence and clinical features of cardiac nodularity, and confirm its close association with active H. pylori infection.

Endoscopy-based Kyoto classification score of gastritis related to pathological topography of neutrophil activity

BACKGROUND

Endoscopy-based Kyoto classification for gastritis and pathological topographic distribution of neutrophil infiltration are correlated with gastric cancer risk.

AIM

To investigate the association between Kyoto classification and the topographic distribution of neutrophil activity.

METHODS

Kyoto classification score, ranging from 0 to 8, consisted of atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness. Neutrophil activity was scored according to the updated Sydney System using biopsy samples obtained from the greater curvature of the corpus and the antrum. The participants were divided into four categories, inactive stomach, antrum-predominant gastritis, pangastritis, and corpus-predominant gastritis, based on the topographic distribution of neutrophil activity. Effects of sex, age, body mass index, drinking habit, smoking habit, family history of gastric cancer, serum Helicobacter pylori (H. pylori) antibody, and Kyoto score on topography of neutrophil infiltration were analyzed.

RESULTS

A total of 327 patients (comprising 50.7% women, with an average age of 50.2 years) were enrolled in this study. H. pylori infection rate was 82.9% with a mean Kyoto score of 4.63. The Kyoto score was associated with the topographic distribution of neutrophil activity. Kyoto scores were significantly higher in the order of inactive stomach, antrum-predominant gastritis, pangastritis, and corpus-predominant gastritis (3.05, 4.57, 5.21, and 5.96, respectively). Each individual score of endoscopic findings (i.e., atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness) was correlated with the topographic distribution of neutrophil activity. On multivariate analysis, the Kyoto score, age, and serum H. pylori antibody were independently associated with the topographic distribution of neutrophil activity.

CONCLUSION

The Kyoto classification score was associated with the topographic distribution of neutrophil activity.

Molecular Mechanisms Contributing Bacterial Infections to the Incidence of Various Types of Cancer

Cancer causes a major health concern worldwide due to high incidence and mortality rates. To accomplish this purpose, the Scopus, PubMed, and Web of Science databases were searched using the keywords bacteria and cancer. Most of published research addressed several different factors that induced cancer, such as toxins, medications, smoking, and obesity. Nonetheless, few studies are dealing with cancer induction via bacterial infection. In addition, mechanisms of cancer induction via bacterial infections are not well understood. Therefore, in this review, we will shed light on different bacteria that induced cancer via different molecular mechanisms. Among the bacterial infection that induced cancer, Helicobacter pylori was the first recognized bacteria which caused gastric cancer and might be also linked to extragastric cancer in humans. H. pylori has been associated with adenocarcinoma in the distal stomach by its ability to cause severe inflammations. It has been found that inflammations induced cancer via different mechanisms including induction of cell proliferation and production of high levels of free radicals. Recently, free radicals were found to induce and cause various types of cancer. Salmonella typhi has been found to be associated with gallbladder carcinoma (GBC). Also, intercellular infection of lungs with Chlamydia pneumoniae was found to contribute as one of the ethological factors of lung cancer. Moreover, infection of the urinary tract with Staphylococcus aureus, Klebsiella spp., and Proteus mirabilis has been found to cause bladder cancer. These microorganisms produce a high level of N-nitrosamines which are metabolically activated leading to the generation of alkylating agents that damage DNA and other macromolecules. It is concluded that a certain bacterium is linked with induction of a specific type of cancer via different molecular and biochemical mechanisms as discussed in the text in details. This infection could potentially affect human health in different ways. In addition, it is important to know the possible factors involved in cancer induction for better treatment of cancer patients.

Fundic gland polyp prevalence according to Helicobacter pylori infection status

BACKGROUND AND AIM

The prevalence of fundic gland polyp (FGP) occurrence has not been clarified in individuals with Helicobacter pylori infection post-eradicated status. This study was performed to examine the relationship between FGP prevalence and H. pylori infection status.

METHODS

We enrolled 3400 subjects (2185 male subjects and 1215 female subjects; mean age 54.7 ± 9.5 years) with known H. pylori infection status and who underwent an upper gastrointestinal endoscopy examination as part of an annual check-up. Subjects without and with H. pylori infection numbered 1617 and 239, respectively, while 1544 had a post-eradication status. The presence of FGP and degree of gastric mucosal atrophy were determined in each subject using an endoscopic method.

RESULTS

Endoscopy findings showed FGPs in 1029 (30.3%) of all subjects. The prevalence ratio of FGP positivity in H. pylori-negative, H. pylori-positive, and post-eradicated subjects was 51.9%, 1.7%, and 12.0%, respectively. Multiple logistic regression analysis revealed that female gender, older age, milder gastric mucosal atrophy, and anti-secretory therapy were significant risk factors for FGP occurrence. As compared with H. pylori-positive subjects, the odds ratios for H. pylori-negative and post-eradication status were 48.3 and 6.6, respectively (P < 0.001). In the post-eradication status subjects, longer duration following bacterial eradication was a significant risk factor for occurrence of FGPs.

CONCLUSION

The risk of FGP occurrence in individuals who have undergone H. pylori eradication treatment is lower as compared with those who have never been infected. However, that risk increases over time following eradication.

Nodularity-like appearance in the cardia: novel endoscopic findings for Helicobacter pylori infection

Background and study aims   Helicobacter pylori -associated nodular gastritis, which is associated with follicular lymphoid hyperplasia, is mainly recognized in the antrum. However, we have also observed nodularity-like appearance in the cardia. This study aimed to investigate the clinical significance of cardiac nodularity-like appearance in H. pylori -associated gastritis. Patients and methods  Patients who underwent esophagogastroduodenoscopy and were evaluated for H. pylori infection for the first time were enrolled. A nodularity-like appearance in the cardia was defined as a miliary nodular appearance or scattered appearances of small circular whitish coloration. H. pylori infection was diagnosed according to serum anti- H. pylori antibody and the urea breath test or histology. Accuracy of the H. pylori infection diagnoses based on nodularity-like appearance were assessed. Results  Among 265 patients, 42 patients (15.8 %) were diagnosed as positive for H. pylori . Cardiac nodularity-like appearance and antral nodularity were recognized in 25 and 15 patients, respectively. In accuracy of predicting H. pylori by cardiac nodularity-like appearance, specificity was 0.996, sensitivity was 0.571, positive predictive value was 0.960, negative predictive value was 0.925, and accuracy was 0.928. The sensitivity of cardiac nodularity-like appearance was significantly higher than that of antral nodularity ( P  = 0.0284). Conclusions  Cardiac nodularity-like appearance had a high accuracy rate for H. pylori infection diagnosis. Cardiac nodularity-like appearance was found more frequently than antral nodularity.

Helicobacter pylori eradication improved the Kyoto classification score on endoscopy

Background and Aim

Endoscopy‐based Kyoto classification predicts the risk of Helicobacter pylori infection and gastric cancer; however, the change in score following H. pylori eradication remains unknown. We retrospectively compared the Kyoto score before and after H. pylori eradication.

Methods

H. pylori‐positive patients who underwent baseline esophagogastroduodenoscopy (EGD), successful H. pylori eradication, and surveillance EGD were enrolled. The Kyoto score is a sum of scores for atrophy (Kimura‐Takemoto atrophic‐border classification none or C1: 0, C‐II or C‐III: 1, O‐I to O‐III: 2), intestinal metaplasia (none: 0, antrum: 1, corpus and antrum: 2), enlarged folds (absence: 0, presence: 1), nodularity (absence: 0, presence: 1), and diffuse redness (none: 0, mild: 1, severe: 2) and ranges from 0 to 8.

Results

Eighty‐three patients (mean age: 54.9 years; 65.1% women) were enrolled. The mean duration from successful eradication to surveillance EGD was 256 days. The Kyoto score significantly decreased from 3.90 to 2.78 following H. pylori eradication (P < 0.001). Scores for endoscopic atrophy (from 1.43 to 1.46, P = 0.638) and endoscopic intestinal metaplasia (from 0.53 to 0.47, P = 0.543) did not change; however, there was significant improvement in the scores for enlarged folds (from 0.14 to 0.00, P = 0.002), nodularity (from 0.18 to 0.04, P = 0.002), and diffuse redness (from 1.61 to 0.82, P < 0.001).

Conclusion

The Kyoto classification score decreased following H. pylori eradication. A decrease in the scores for enlarged folds, nodularity, and diffuse redness contributed to the decrease in Kyoto score.

Endoscopic Kyoto classification of Helicobacter pylori infection and gastric cancer risk diagnosis

Recent advances in endoscopic technology allow detailed observation of the gastric mucosa. Today, endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori (H. pylori) infection and evaluate gastric cancer risk. In 2013, the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification, a new grading system for endoscopic gastritis. The Kyoto classification organized endoscopic findings related to H. pylori infection. The Kyoto classification score is the sum of scores for five endoscopic findings (atrophy, intestinal metaplasia, enlarged folds, nodularity, and diffuse redness with or without regular arrangement of collecting venules) and ranges from 0 to 8. Atrophy, intestinal metaplasia, enlarged folds, and nodularity contribute to gastric cancer risk. Diffuse redness and regular arrangement of collecting venules are related to H. pylori infection status. In subjects without a history of H. pylori eradication, the infection rates in those with Kyoto scores of 0, 1, and ≥ 2 were 1.5%, 45%, and 82%, respectively. A Kyoto classification score of 0 indicates no H. pylori infection. A Kyoto classification score of 2 or more indicates H. pylori infection. Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8, respectively. A Kyoto classification score of 4 or more might indicate gastric cancer risk.

Small-caliber endoscopes are more fragile than conventional endoscopes

Background and study aims  The repair costs of gastrointestinal endoscopes account for a significant proportion of the total budget of an endoscopy unit. This study evaluated the repair costs of small-caliber endoscopes and conventional endoscopes used in esophagogastroduodenoscopy (EGD). Patients and methods  A retrospective analysis of upper gastrointestinal endoscope damage and repair costs between April 2012 and May 2019 was performed at the Toyoshima Endoscopy Clinic. Conventional endoscopes (GIF-H260, GIF-HQ290, and GIF-H290Z) were used for transoral EGD while small-caliber endoscopes (GIF-XP260N and GIF-XP290N) were used for transnasal or transoral EGD. Results  Three small-caliber endoscopes and five conventional endoscopes were used for 1,031 procedures and 31,192 procedures, respectively. The number of procedures/damage incidence for small-caliber endoscope and conventional endoscopes was 344 and 1950, respectively. Damage incidence for small-caliber endoscopes was significantly higher than for conventional endoscopes ( P  = 0.014). Repair costs/procedure were $ 5.95 ± $132 for small-caliber endoscopes and $2.41 ± $115 for conventional endoscopes. Repair costs/procedure for small-caliber endoscopes were more than twice those for conventional endoscopes. Conclusions  Small-caliber endoscopes are more fragile than conventional endoscopes.

Long-term effect of Helicobacter pylori eradication on prevalence of reflux esophagitis

BACKGROUND AND AIM

This study aimed to clarify the long-term effect of Helicobacter pylori eradication on the prevalence of reflux esophagitis (RE).

METHODS

We enrolled 8123 individuals (male 5286, female 2837; mean age 54.2 ± 9.3 years) who visited our medical center for an annual checkup between April 2016 and December 2018 and in whom the status of H. pylori infection could be determined. The presence of endoscopically proven RE was determined and compared based on that infection status.

RESULTS

Reflux esophagitis was observed in 898 subjects (11.1%). The rates of prevalence in subjects without and with H. pylori infection and with a post-eradication status were 14.0%, 3.7%, and 10.1%, respectively (P < 0.001). Multiple logistic regression analysis of those positive for RE showed male gender, elevated body mass index, habitual drinking, habitual smoking, larger diaphragmatic hiatus size, and milder gastric mucosal atrophy to be significant risk factors. As compared with H. pylori negative, the odds ratios for H. pylori-positive and post-eradication status were 0.225 and 0.703, respectively. When post-eradication subjects were divided according to duration following eradication, RE prevalence was increased in association with a longer duration. Multiple logistic regression analysis revealed longer duration after H. pylori eradication to be a significant risk factor for RE.

CONCLUSIONS

The risk of RE developing in individuals following eradication of H. pylori is considered to be lower as compared with those never infected. However, the risk for RE increases as the period following H. pylori eradication is extended.

Adverse events associated with bidirectional endoscopy with midazolam and pethidine

Same-day bidirectional endoscopy has been reported to reduce recovery time, and procedure-related cost. The safety of bidirectional endoscopy vs colonoscopy only, while using midazolam and pethidine, has never been evaluated. We reviewed 1,202 consecutive patients who underwent bidirectional endoscopy or colonoscopy only with administration of midazolam and pethidine in Toyoshima Ensdoscopy Clinic. We compared the clinical characteristics and adverse events associated with method of endoscopy (colonoscopy only vs bidirectional endoscopy). Furthermore, multivariate logistic regression analyses were conducted to study the role of age, sex, use of sedative, polypectomy, and bidirectional endoscopy in adverse events. In the bidirectional endoscopy group, the doses of pethidine and midazolam, and the incidence rates of hypoxia and posto-endoscopic nausea were significantly higher. On multivariate analysis, age (odds ratio = 1.061, p<0.001), use of pethidine (odds ratio = 4.311, p = 0.003), and bidirectional endoscopy (odds ratio = 3.658, p<0.001) were independently associated with hypoxia. On multivariate analysis, female sex (odds ratio = 10.25, p = 0.027) and bidirectional endoscopy (odds ratio = 6.051, p = 0.022) were independently associated with post-endoscopic nausea. In conclusion, bidirectional endoscopy could increase hypoxia in elderly patients using pethidine and post-endoscopic nausea in female patients.

Prevalence of Autoimmune Gastritis in Individuals Undergoing Medical Checkups in Japan

Objective Based on both endoscopic findings and serum auto-antibody levels, we determined the prevalence of autoimmune gastritis (AIG), which has not been previously reported, in individuals who underwent health checkup examinations in Japan. Methods At total of 6,739 subjects (4,288 males, 2,451 females; mean age 52.1 years) underwent an upper gastrointestinal endoscopic examination as part of an annual medical checkup. Those suspected to have AIG based on endoscopic evidence of proximal-predominant gastric mucosal atrophy were further examined for the presence of anti-parietal cells and anti-intrinsic factor antibodies, with a final diagnosis of AIG made in cases found to be positive for either or both of those factors. Results Of the 6,739 examined subjects, 46 were suspected to have AIG based on the endoscopic findings, of whom 33 were finally diagnosed with AIG, for an overall prevalence 0.49% (females 0.65%, males 0.40%). Seven with AIG also had thyroid disease, including Hashimoto's and Basedow disease, while none with AIG showed anemia in blood test findings. The prevalence of AIG was not different regardless of the H. pylori infection status (negative, positive, post-eradicated). Conclusion In individuals who underwent an upper gastrointestinal endoscopic examination as part of an annual checkup in Japan, the prevalence of AIG was 0.49%. We concluded that it is not uncommon for asymptomatic and healthy individuals to have AIG, and propose that additional studies are needed to clarify its prevalence as well as to establish the criteria used for diagnosis.

Relationship of Helicobacter pylori Infection with Gastric Black Spots Shown by Endoscopy

Objective The recently reported endoscopic finding of black spots is defined as black pigmentation in gastric mucosa. We attempted to clarify the relationship between the Helicobacter pylori infection status and black spot occurrence. Methods The study subjects were 1,600 individuals who underwent an annual medical checkup and whose H. pylori status could be determined. Upper endoscopic examinations were performed in all, and the presence of black spots in the stomach as well as the degree of gastric mucosal atrophy were determined. Results Among the 1,600 enrolled subjects, 784 underwent eradication for H. pylori, of whom 144 were originally H. pylori-positive and 672 H. pylori-negative. Black spots in the stomach were observed in 156 (9.8%). The rate of prevalence of black spots in the H. pylori-positive and H. pylori-negative subjects was 2.1% and 1.5%, respectively, while that in subjects after undergoing eradication of H. pylori was 18.2%. A multiple logistic regression analysis demonstrated that an older age and post-eradication status were significant factors for black spot occurrence, while proton pump inhibitor treatment showed a tendency to be a risk factor. In subjects with post-eradication status, a higher grade of gastric mucosal atrophy was a significant risk factor for the occurrence of black spots. Conclusion H. pylori post-eradication status and an older age were significant factors related to the appearance of black spots, and a higher grade of gastric mucosal atrophy was also a significant risk factor in subjects who had undergone successful eradication.

A combination of serum anti-Helicobacter pylori antibody titer and Kyoto classification score could provide a more accurate diagnosis of H pylori

Background

We previously showed that the endoscopic Kyoto classification for gastritis could predict Helicobacter pylori infection in individuals with a high negative titer of serum anti-H pylori antibodies. This study evaluated H pylori infection and the Kyoto classification score in patients with a low negative titer (<3 U/ml), high negative titer (3–9.9 U/ml), low positive titer (10–49.9 U/ml), and high positive titer (≥50 U/ml).

Methods

Serum antibody levels, Kyoto classification score and histology were investigated in 870 individuals with no history of H pylori-eradication therapy. Urea breath tests (UBTs) were additionally conducted for patients with a low negative titer and a Kyoto score ≥1 or an antibody titer ≥10 U/ml and a Kyoto score of 0 or 1. UBTs and/or histological studies were conducted for participants with a high negative titer.

Results

False diagnoses based on anti-H pylori antibody titers were observed in 0.3% of the low-negative-titer group, 11.7% of the high-negative-titer group, 18.9% of the low-positive-titer group and 2.2% of the high-positive-titer group. Surprisingly, false diagnoses based on antibody titers were noted in 63.2% of patients with a low positive titer and a Kyoto score of 0 and in 62.5% of patients with a high negative titer and a Kyoto score ≥2, respectively.

Conclusions

Endoscopic findings could predict false diagnoses determined using serum antibody titers.

Serum anti-Helicobacter pylori antibody titer and its association with gastric nodularity, atrophy, and age: A cross-sectional study

AIM

To clarify the role of serum anti-Helicobacter pylori (H. pylori) antibody titers in gastric cancer.

METHODS

In this cross-sectional study, the effect of patients’ baseline characteristics and endoscopic findings on their serum antibody titers were assessed. We evaluated consecutive patients who underwent esophagogastroduodenoscopy and their first evaluation for H. pylori infection using a serum antibody test. We excluded patients with a history of eradication therapy. The participants were divided into four groups according to their E-plate serum antibody titer. Patients with serum antibody titers < 3, 3-9.9, 10-49.9, and ≥ 50 U/mL were classified into groups A, B, C, and D, respectively.

RESULTS

In total, 874 participants were analyzed with 70%, 16%, 8.7%, and 5.1% of them in the groups A, B, C, and D, respectively. Patients in group C were older than patients in groups A and B. Gastric open-type atrophy, intestinal metaplasia, enlarged folds, diffuse redness, and duodenal ulcers were associated with a high titer. Regular arrangements of collecting venules, fundic gland polyps, superficial gastritis, and gastroesophageal reflux disease were related to a low titer. Multivariate analysis revealed that nodularity (P = 0.0094), atrophy (P = 0.0076), and age 40-59 years (vs age ≥ 60 years, P = 0.0090) were correlated with a high serum antibody titer in H. pylori-infected patients. Intestinal metaplasia and atrophy were related to age ≥ 60 years in group C and D.

CONCLUSION

Serum antibody titer changes with age, reflects gastric mucosal inflammation, and is useful in predicting the risk of gastric cancer.