High prevalence of duodenal ulcer and gastric cancer in dyspeptic patients in Korea

Different Pathophysiology of Gastritis between East and West? An Asian Perspective

Background

The incidence of gastric cancer in Asia is higher than that in Europe and Northern America. Helicobacter pylori infection is the most important factor for the development of atrophic gastritis and gastric cancer. The geographical distribution of the prevalence and virulence factors of H. pylori are important to understand the difference between gastritis in the East and West.

Summary

Articles comparing gastritis cases between eastern and western countries showed that the severity of gastritis is closely related to the risk of gastric cancer, and the severity of gastritis is more advanced in East Asia. Although the prevalence of H. pylori infection is closely associated with the incidence of gastric cancer in European countries, the severity of gastritis and the high incidence of gastric cancer in East Asia are not dependent only on the prevalence of H. pylori infection itself. From the viewpoint of the virulence factors of H. pylori, the East Asian CagA-positive strain (EPIYA motif ABD type) is peculiar in East Asia. Considering comprehensively the geographical distribution of H. pylori subtypes is the most important factor among all prospected risk factors for the incidence of gastric cancer and the rate of development of gastritis. While eating habits, such as salty foods, vegetables and fruits, might influence the progression of gastritis, such factors might be responsible for the geographic heterogeneity of gastritis.

Key Message

East Asian CagA-positive H. pylori is the strongest risk factor for gastric carcinogenesis and the development of gastritis.

Systematic review with meta-analysis: prompt endoscopy as the initial management strategy for uninvestigated dyspepsia in Asia

BACKGROUND

Prompt endoscopy should be considered as an initial strategy for uninvestigated dyspepsia in the background of high prevalence of Helicobacter pylori infection and malignancy. However, with changes of disease patterns and dyspepsia definition, the prevalence of organic lesions at endoscopy in dyspepsia patients and the predictive values of alarm features and age for in malignancy remain unclear in Asian population.

AIMS

To evaluate the appropriateness of prompt endoscopy as an initial dyspepsia management strategy, we investigated the organic lesion detection rates in Asian dyspepsia patients as well as the diagnostic accuracies of alarm features and age thresholds for malignancy.

METHODS

Literature was retrieved from MEDLINE, PubMed, Embase, Cochrane Library and CINAHL Plus. The prevalence rates of organic lesions and young cancer patients among dyspeptic patients and the sensitivities, specificities, likelihood ratios and diagnostic odds ratio (DOR) of alarm features and ages were estimated. The summary receiver operating characteristic curve was constructed and the area under the curve (AUC) calculated. Subgroup, sensitivity and meta-regression analyses were performed.

RESULTS

Of the 18 included studies, 15 reported organic lesion detection rates, and six and five analysed the predictive values of alarm features and ages respectively. The overall malignancy detection rate was 1.3% (95% CI: 0.80-2.10). Among cancer patients, 17.8% (95% CI: 10.90-29.00) were younger than 45 years and 3.0% (95% CI: 2.50-3.50) were younger than 35 years. The diagnostic accuracy of alarm features for predicting malignancy was moderate (DOR: 4.87, 95% CI: 2.72-8.71; AUC = 0.74). The diagnostic accuracy at age >35 years (DOR: 9.41, 95% CI: 7.89-11.21; AUC = 0.82) was better than that at age >45 years (DOR: 3.50, 95% CI: 2.32-5.27; AUC = 0.70).

CONCLUSIONS

The malignancy detection rate and proportion of young cancer patients were high among Asian dyspepsia patients. Alarm features and age were of limited value for predicting malignancy, and prompt endoscopy should be considered as the initial strategy for dyspepsia in Asian populations. The optimal age threshold for endoscopy screening in Asia might be 35 years.

The COX-2-1195AA Genotype Is Associated with Diffuse-Type Gastric Cancer in Korea

BACKGROUND/AIMS

The potential role of the cyclooxygenase (COX)-2 polymorphism has been reported in relation to the risk of gastrointestinal tract malignancies. Therefore, we investigated whether COX-2 polymorphisms are associated with the risk of gastric cancer (GC) in Korea, one of the areas with a high prevalence of this condition.

METHODS

We evaluated the genotypic frequencies of COX-2-765 and -1195 in 100 peptic ulcer patients, 100 GC patients, and 100 healthy controls. The polymorphisms of the COX-2-765 and -1195 genes were analyzed by polymerase chain reaction and restriction fragment length polymorphisms.

RESULTS

The frequencies of the COX-2-1195 GG, GA, and AA genotype were 20%, 60%, and 20% in intestinal-type GC and 8%, 48%, and 44% in diffuse-type GC, respectively (p=0.021). There were no significant differences in the frequency of COX-2-765 genotypes between intestinal-type GC and diffuse-type GC (p=0.603). Age- and sex-adjusted logistic regression analysis showed that the COX-2-1195 AA genotype was the independent risk factor of diffuse-type GC compared with the COX-2-1195 GG genotype (p=0.041; odds ratio, 6.22; 95% confidence interval, 1.077 to 35.870).

CONCLUSIONS

The COX-2-1195 AA genotype may render subjects more susceptible to diffuse-type GC.

Gastritis and gastric atrophy

PURPOSE OF REVIEW

The majority of problems in interpreting gastritis remain Helicobacter related, but their nature has changed. The present review covers gastritis historically through cancer risk staging systems.

RECENT FINDINGS

Key points to remember are: Helicobacter is associated with several forms of gastritis; in the present review, I am focusing on the two ends of the disease, 'Helicobacter pylori infection', that starts with antral predominant gastritis but can continue to oxyntic predominant disease with atrophy; the role Helicobacter pylori plays in autoimmune gastritis with pernicious anemia remains unresolved; gastritis staging systems for cancer risk, namely Baylor and Operative Link on Gastritis Assessment, are currently available.

SUMMARY

As most gastric carcinomas arise on a background of atrophic gastritis, and the risk increases with the extent of atrophy, an index of atrophy location and extent could be useful in predicting patients at greatest risk for carcinoma. It is now possible to stage patients for cancer risk. Nonetheless, in a field such as gastritis in which many issues remain unresolved, a classification or staging system that is more descriptive will likely prove more useful.

Polymorphisms of interleukin-1 and interleukin-2 genes in patients with gastric cancer in Korea

BACKGROUND AND AIM

Interleukin (IL)-1 gene polymorphism has been reported to be associated with the increment of gastric cancer (GC) and the decrement of duodenal ulcers (DU). In addition, IL-2 is known to induce Helicobacter pylori (H. pylori)-associated gastric atrophy, but it is not known whether IL-2 gene polymorphism increases the risk of GC (GC) or peptic ulcer diseases. Therefore, we compared the genotypes of IL-1B, IL-1RN, and IL-2 gene polymorphisms with risk of gastric ulcers (GU), GC, and DU in Korean patients.

METHODS

In total, 116 GU, 122 GC, and 104 DU patients were included consecutively and compared with 100 healthy controls. Polymorphisms of the IL-1B-511/-31 gene, the penta-allelic variable number of tandem repeats of the IL-1RN gene, and the IL-2-330 gene were analyzed by polymerase chain reaction with restriction fragment length polymorphism or confronting two-pair primers methods.

RESULTS

The age-sex-adjusted odds ratios (OR) for the IL-1B-511 T genotype relative to the C/C genotype (OR = 0.82, 95% confidence interval [CI] 0.41-1.65), IL-1RN*2 genotype relative to the L/L genotype (OR = 0.85, 95% CI 0.41-1.78), and IL-2-330 T genotype relative to the G/G genotype (OR = 1.94, 95% CI 0.76-4.96) were not increased in GC. There was also no significant difference in the genotypes of these cytokine polymorphisms between the study group (GU or DU) and control group. In addition, genotypic frequency was not associated with H. pylori positivity and histological type of GC.

CONCLUSION

IL-1B-511, IL-1RN, and IL-2 genetic polymorphisms were not important contributors to the pathogenesis of GU, GC, and DU in Korean patients.

Comparison of the 13C-urea breath test and the endoscopic phenol red mucosal pH test in the quantification of Helicobacter pylori infection loading

BACKGROUND/AIMS

The (13)C-urea breath test (UBT) is a semiquantitative test for measuring Helicobacter pylori infection loading. H. pylori produces ammonia, which elevates the pH of the gastric mucosa and is detectable via endoscopy using a phenol red indicator. We evaluated whether this test could be used to diagnose H. pylori infection and whether phenol red staining was correlated with (13)C-UBT results.

METHODS

One hundred and twenty-three patients participated. The UBT was performed after ingestion of a capsule containing urea. A change in (13)C-UBT >2 ppt was selected as the cutoff value for diagnosing infection. After spraying evenly with a 0.1% phenol red solution, the pH of the gastric mucosal surface was measured using an antimony electrode through the biopsy channel.

RESULTS

The pH of stained mucosa (6.9+/-0.4) was significantly higher than that of unstained mucosa (1.9+/-0.8; p<0.001), and the H. pylori detection rate confirmed via histology was higher in stained versus unstained mucosa (p<0.01). Extensive mucosal staining resulted in a higher detection rate (p<0.001). The UBT produced results were very similar to those obtained via histological detection in stained mucosa (p<0.001). The extent of staining, expressed as a staining score, was positively correlated with the change in (13)C-UBT (r=0.426, p<0.001). A significant correlation was also observed between the histologically determined H. pylori density and (13)C-UBT results (r=0.674, p<0.001).

CONCLUSIONS

H. pylori infection elevates gastric mucosal surface pH, and endoscopic phenol red staining may be an alternative method for the diagnosis of H. pylori infection.

Gastric atrophy, diagnosing and staging

H pylori is now accepted as the cause of gastritis and gastritis-associated diseases, such as duodenal ulcer, gastric ulcer, gastric carcinoma, and gastric MALT lymphoma. The natural history of H pylori gastritis includes inflammation progressing from the antrum into the adjacent corpus resulting in an atrophic front of advancing injury leading to a reduction in acid secretion and eventual loss of parietal cells and development of atrophy. Sub-typing intestinal metaplasia has no clinical value to the patient, the pathologist, or the endoscopist. The pattern, extent, and severity of atrophy, with or without intestinal metaplasia, is a far more important predictor than is intestinal metaplasia subtype. The challenge remains to identify a reliable marker that relates to pre-malignant potential.

H pylori receptor MHC class II contributes to the dynamic gastric epithelial apoptotic response

AIM: To investigate the role of MHC class II in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.

METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC class II and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively.

RESULTS: Pretreatment of N87 cells with the anti-MHC class II IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class II resulted in a marked reduced caspase activation, while simple ligation of MHC class II did not. Crosslinking of MHC class II also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class II IgM blocked the recruitment of FADD to the cell surface.

CONCLUSION: The results presented here demonstrate that the ability of MHC class II to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. Furthermore, while previous research has demonstrated that MHC class II signaling can be pro-apoptotic during extended ligation, we have shown that the crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class II to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.

H pylori receptor MHC class II contributes to the dynamic gastric epithelial apoptotic response

AIM: To investigate the role of MHC class II in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.

METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC class II and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively.

RESULTS: Pretreatment of N87 cells with the anti-MHC class II IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class II resulted in markedly reduced caspase activation, while simple ligation of MHC class II did not. Crosslinking of MHC class II also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class II IgM blocked the recruitment of FADD to the cell surface.

CONCLUSION: The ability of MHC class II to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. The crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class II to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.

The changing epidemiology of GERD: geography and Helicobacter pylori

BACKGROUND

Issues have arisen regarding H. pylori infection and GERD that have caused unnecessary confusion among practicing physicians. In the last century GERD became increasingly recognized in the West and it has become evident that the prevalence of GERD is now occurring in many previously underdeveloped countries.

METHODS

This review article fosters understanding of the issues by focusing on the esophageal acid load and the factors that control it. In particular, we discuss the effects of the change in the patterns of gastritis that have occurred naturally as well as after H. pylori eradication and correlate those changes with their effects on the esophageal acid load. We show how it is possible to separate gastroesophageal reflux from gastroesophageal reflux disease based on differences in esophageal acid load. We also describe how the practice of assessing gastroesophageal reflux based on the time the intraesophageal pH is less than 4 resulted in investigators systematically discarding data critical to understanding of the effect of their interventions on esophageal acid load. Testable hypotheses are presented to explain the interactions between H. pylori and GERD and between H. pylori and the changing epidemiology of GERD.

CONCLUSIONS

We propose that the confusion regarding H. pylori and the changing epidemiology of GERD is based on the failure to critically examine the historical evidence in relation to the other H. pylori-related diseases as well as reliance on techniques that are either unable to measure, or systematically discard data critical for understanding effects of various interventions on the esophageal acid load. This has resulted in propagation of erroneous concepts regarding H. pylori and adenocarcinoma of the esophagus and has resulted in some patients being denied appropriate therapy.

Delta (13)C-urea breath test value is a useful indicator for Helicobacter pylori eradication in patients with functional dyspepsia

BACKGROUND

Eradication of Helicobacter pylori is not routinely recommended for the symptomatic relief and the prevention of gastric cancer in patients with functional dyspepsia. The present study investigated a useful indicator of H. pylori eradication in such patients by determining the optimal cutoff value of a 13C-urea breath test (UBT).

METHODS

One hundred dyspeptic patients participated in the study. Dyspepsia was scored, and a 13C-UBT administered. A level of delta 13C-UBT of>4 per thousand was diagnosed as H. pylori-positive. After the stomach was endoscopically sprayed with phenol red, biopsy specimens were taken from the antrum, body and cardia of the stomach for the assessment of H. pylori density, and activity (neutrophil infiltration) and degree (lymphocyte infiltration) of gastritis.

RESULTS

Correlation between delta 13C-UBT and dyspepsia score was not found. Delta 13C-UBT significantly correlated with H. pylori density score in the total stomach (r = 0.53, P < 0.0001), neutrophil (r = 0.34, P = 0.0005) and lymphocyte score (r = 0.69, P < 0.0001). Twenty-six of the 100 subjects had a neutrophil score of >or=4, lymphocyte score of >or=4, and H. pylori score of >or=4. Their 95% confidence interval of mean was 58.2 per thousand, which reflects moderate to marked acute and chronic gastritis, and dense H. pylori colonization.

CONCLUSIONS

The 13C-UBT is a reliable semiquantitative test to assess H. pylori density and the activity and degree of gastritis. It is proposed that H. pylori eradication therapy might be beneficial for patients with functional dyspepsia with a delta 13C-UBT of >58.2 per thousand.

Geographic differences in the distribution of intestinal metaplasia in duodenal ulcer patients

OBJECTIVE

A strong correlation exists between atrophic gastritis and the intestinal type of gastric carcinoma. Duodenal ulcer disease characteristically has an antral predominant gastritis and a lower risk for gastric cancer. The aim of this study was to investigate the extent and distribution of intestinal metaplasia in duodenal ulcer in countries differing in gastric cancer incidence.

METHODS

Topographically mapped gastric biopsy specimens (median 11) were obtained from patients with duodenal ulcer in four countries (Korea, Colombia, USA, and South Africa). Sections were stained with a triple stain and evaluated for Helicobacter pylori (H. pylori), active inflammation, and intestinal metaplasia.

RESULTS

One hundred and sixty-five patients with duodenal ulcer were examined (29 from Korea, 52 from Colombia, 62 from the USA, and 22 from South Africa). The percentage of biopsies with intestinal metaplasia was significantly greater in Korean patients (86%) compared with that in other countries (50%) (p = 0.0004). Intestinal metaplasia was most prevalent in the antrum lesser curve and greater curve, and the body lesser curve. Intestinal metaplasia was present in the gastric corpus of 38% of duodenal ulcer patients from Korea compared with an average of 10% elsewhere (p = 0.018). No differences were observed in the density or distribution of H. pylori infection or in the degree of active gastritis between countries.

CONCLUSIONS

Although antral predominant gastritis is the prevalent pattern of gastritis in duodenal ulcer, intestinal metaplasia in the gastric corpus may be found with geographic differences. These findings suggest that duodenal ulcer and gastric cancer are not mutually exclusive diseases but are rather ends of the spectrum of H. pylori infection.

Omeprazole or ranitidine bismuth citrate triple therapy to treat Helicobacter pylori infection: a randomized, controlled trial in Vietnamese patients with duodenal ulcer

AIM

To evaluate the effectiveness of triple therapy containing either omeprazole or ranitidine bismuth citrate (RBC) to treat H. pylori infection in Vietnamese duodenal ulcer patients.

METHODS

Patients infected with H. pylori were randomized to receive either omeprazole (20 mg b.d.), clarithromycin (500 mg b.d.) and amoxycillin (1 g b.d.) for 10 days (OAC), or RBC (400 mg b.d.), clarithromycin (500 mg b.d.) and amoxycillin (1 g b.d.) for 10 days (RAC). H. pylori eradication and ulcer healing was established by a follow-up oesophagogastroduodenoscopy (EGD) at least 4 weeks after therapy. Side-effects and compliance were assessed.

RESULTS

One hundred and four out of 108 (96%) patients with a duodenal ulcer were infected with H. pylori. Eighty per cent of infected patients had detectable CagA IgG antibodies. Fifty-seven patients received OAC and 47 received RAC. OAC eradicated H. pylori in 91 and 86% of patients by per protocol (PP) and intention-to-treat (ITT) analysis, respectively. PP and ITT eradication rates for RAC were 96 and 91%. Ulcer healing at the follow-up EGD was 89% with OAC and 100% with RAC. Side-effects were minor. No patient failed to complete the protocol due to side-effects.

CONCLUSION

Triple therapy with either omeprazole or RBC is highly effective in eradicating H. pylori and healing duodenal ulcer in Vietnamese patients.

Garlic or jalapeño peppers for treatment of Helicobacter pylori infection

OBJECTIVE

There have been a number of reports that natural foods such as garlic, honey, and capsaicin can inhibit Helicobacter pylori in vitro and each report has suggested the natural ingredient be used for treatment of the infection. We investigated whether garlic or capsaicin-containing peppers would actually inhibit H. pylori in vivo.

METHODS

We performed a prospective crossover study in healthy H. pylori-infected adults. We used the urea breath test to assess the status of the H. pylori infection. On separate days subjects received three test meals consisting of beef, tortillas, and salad with one of the following: fresh garlic (10 sliced cloves), capsaicin (six sliced fresh jalapeños), two tablets of bismuth subsalicylate (Pepto-Bismol, positive control), or nothing added (negative control). Breath testing was done before the first meal, the evening meal, and the following morning. At least 2 days elapsed between the test substances.

RESULTS

Twelve subjects participated (seven men, five women), with an average age of 41.4 yr, range 27-51 yr. Ten subjects received garlic, six received jalapeños, and 11 received bismuth. Neither garlic nor capsaicin had any in vivo effect on H. pylori (median urease activity 28.5 vs 39.8 and 43.7 vs 46.6 before and after garlic and jalapeños, respectively) (p > 0.8). Bismuth had a marked inhibitory effect (median 55.8 vs 14.3 before and after bismuth) (p < 0.001), respectively.

CONCLUSIONS

This study did not support a role for either garlic or jalapeños in the treatment of H. pylori infection. Caution must be used when attempting to extrapolate data from in vitro studies to the in vivo condition.