Relationship of Helicobacter pylori to serum pepsinogens in an asymptomatic Japanese population

Epidemiology of Helicobacter pylori infection in children: a serologic study of the Kyushu region in Japan

BACKGROUND

The prevalence of Helicobacter pylori infection in children varies as a function of socioeconomic development, with low rates in developed countries and high rates in developing countries. The prevalence of H. pylori infection in Japanese children is unknown.

METHODS

The present study examined the effect of living conditions on the prevalence of H. pylori infection in children. We determined the prevalence of H. pylori infection in healthy children of the Kyushu region in Japan and compared it with the prevalence in institutionalized children with severe neurologic illness. Serum concentrations of anti-H. pylori IgG antibody were measured by an enzyme-linked immunosorbent assay in 336 healthy children and 56 patients with severe neurologic impairment. An antibody concentration > 50 units/mL was taken as evidence of infection.

RESULTS

The prevalence of H. pylori seropositivity in healthy children increased with age (P < 0.0001) and was 29% in children 15-19 years of age. This value is slightly higher than prevalences reported in developed countries (5-15%), but is lower than in developing countries (30-60%). Seropositivity did not vary with respect to gender, water supply or location of housing. Helicobacter pylori seropositivity was more prevalent among institutionalized children aged 5-19 years than their healthy counterparts (P < 0.005).

CONCLUSIONS

The intermediate prevalence of H. pylori seropositivity in healthy children between that measured in developed and developing countries is consistent with the socioeconomic 'westernization' of Japan.

Associations of food-cobalamin malabsorption with ethnic origin, age, Helicobacter pylori infection, and serum markers of gastritis

OBJECTIVES

Food-cobalamin malabsorption is common in patients with low cobalamin levels. However, characterization of affected subjects has been limited. The aim of this study was to analyze demographic and gastric data in a large study population.

METHODS

Data were collected prospectively in 202 subjects (43 volunteers and 159 patients) who underwent the egg yolk-cobalamin absorption test (EYCAT). H. pylori status was determined in 167 of the subjects, serum gastrin and antiparietal cell antibody in 158 and pepsinogen (PG) I and PG II levels in 133.

RESULTS

Latin American and black patients had lower EYCAT results than did white or Asian-American ones (p = 0.0001) and had severe food-cobalamin malabsorption (EYCAT < 1%) more often (p = 0.0001). Age correlated inversely with EYCAT results (p = 0.02). H. pylori infection was associated with food-cobalamin malabsorption (p = 0.0001), especially with severe malabsorption where 29/37 subjects (78.4%) were infected. Malabsorption was also associated with higher gastrin levels (p = 0.0001) and lower PG I levels (p = 0.01) and PG I:PG II ratios (p = 0.0001). Multivariate analysis showed that ethnic origin, gastrin levels, H. pylori infection and, to a lesser extent, age were independently associated with the EYCAT results.

CONCLUSIONS

Latin American and black patients have food-cobalamin malabsorption more often than do white and Asian-American patients. This association is independent of the malabsorption's association with H. pylori infection, markers of gastritis, such as gastrin, and older age. The patterns of gastric tests suggest that malabsorption may be due to diverse mechanisms, not just atrophic gastritis. The possible role of H. pylori infection in many cases of severe food-cobalamin malabsorption also suggests avenues of treatment and prevention.

Aging increases, and duodenal ulcer reduces the risk for intestinal metaplasia of the gastric corpus in Japanese patients with dyspepsia

BACKGROUND AND AIMS

The classification of gastritis by using the revised Sydney system suggests that there are two types of Helicobacter pylori-related gastritis. The aim of the present study was to examine the risk factors that might be involved in the presence of either atrophic gastritis or intestinal metaplasia of the gastric corpus of Japanese patients.

METHODS

Biopsy samples were obtained from the gastric corpus in 154 patients with dyspepsia, and the degree of atrophy or intestinal metaplasia was determined histologically. The correlation between several variables and presence of atrophy or intestinal metaplasia was evaluated by using multivariate analysis.

RESULTS

Among the 11 variables, which included age, peptic ulcer diseases and H. pylori infection, H. pylori infection was the major risk factor associated with the presence of atrophic gastritis or intestinal metaplasia of the gastric corpus. In contrast, duodenal ulcer (DU) disease reduced the risk of contracting both conditions. Age was an independent risk factor only for intestinal metaplasia of the gastric corpus. When 128 H. pylori-positive subjects were analyzed, DU and age were similarly associated with the presence of both conditions.

CONCLUSIONS

These results suggest that DU reduces the risk for contracting atrophic gastritis and intestinal metaplasia, and age is an independent risk factor for intestinal metaplasia of the gastric corpus in dyspeptic Japanese patients.

CYP2C19 genotype status and intragastric pH during dosing with lansoprazole or rabeprazole

BACKGROUND

CYP2C19 has an important role in the catabolism of several proton pump inhibitors. However, the relative contribution of CYP2C19-mediated metabolism varies among the different proton pump inhibitors.

AIM

To determine the effect of CYP2C19 genotype status on intragastric pH during dosing with lansoprazole or rabeprazole.

SUBJECTS AND METHODS

The subjects were 20 male volunteers without Helicobacter pylori infection. Their CYP2C19 genotype status was determined by a polymerase chain reaction-restriction fragment length polymorphism method. Twenty-four-hour monitoring of intragastric acidity was performed three times: once without medication, once on the last day of a 7-day course of rabeprazole, and once on the last day of a 7-day course of lansoprazole.

RESULTS

Subjects were divided into three groups on the basis of their CYP2C19 genotype status: homozygous extensive metabolizers (homo-EMs, n=7), heterozygous extensive metabolizers (hetero-EMs, n=9), and poor metabolizers (PMs, n=4). The median pH during rabeprazole administration was not influenced by CYP2C19 genotype. On the other hand, the median pH in PMs during lansoprazole dosing was higher than in homo-EMs and hetero-EMs. The percentage of time with pH < 4.0 had a similar tendency to that of median pH.

CONCLUSION

CYP2C19 genotype status influences gastric acid suppression by lansoprazole, but not by rabeprazole.

A comprehensive review of the natural history of Helicobacter pylori infection in children

Across populations of children, Helicobacter pylori prevalence ranges from under 10% to over 80%. Low prevalence occurs in the U.S., Canada, and northern and western Europe; high prevalence occurs in India, Africa, Latin America, and eastern Europe. Risk factors include socioeconomic status, household crowding, ethnicity, migration from high prevalence regions, and infection status of family members. H. pylori infection is not associated with specific symptoms in children; however, it is consistently associated with antral gastritis, although its clinical significance is unclear. Duodenal ulcers associated with H. pylori are seldom seen in children under 10 years of age. H. pylori-infected children demonstrate a chronic, macrophagic, and monocytic inflammatory cell infiltrate and a lack of neutrophils, as compared with the response observed in adults. The effect of H. pylori infection on acid secretion in children remains poorly defined. The events that occur during H. pylori colonization in children should be studied more thoroughly and should include urease activity, motility, chemotaxis, adherence, and downregulation of the host response. The importance of virulence determinants described as relevant for disease during H. pylori infection has not been extensively studied in children. Highly sensitive and specific methods for the detection of H. pylori in children are needed, especially in younger pediatric populations in which colonization is in its early phases. Criteria for the use of eradication treatment in H. pylori-infected children need to be established. Multicenter pediatric studies should focus on the identification of risk factors, which can be used as prognostic indicators for the development of gastroduodenal disease later in life.

Trend toward a reduced prevalence of Helicobacter pylori infection, chronic gastritis, and gastric cancer in Japan

It is speculated that declines in H. pylori infection and gastritis over the past few decades may lead to a decline in gastric cancer in Japan, supplemented by excellent procedures for the early detection of gastric cancer. Because H. pylori infection rarely is acquired in adult life, once it is eradicated, reinfection would not be expected in adult patients. It seems likely that adequate treatment of H. pylori infection would provide long-term protection against gastric cancer.

Gastritis and gastric cancer. Asia

In Japan, high prevalences of H. pylori infection and AG are found, which seem to be causes for the high incidence of gastric cancer. H. pylori infection is not a sole cause of gastric cancer, however. Environmental factors, including a diet high in salt, also might be involved. For accurate diagnosis of H. pylori infection and AG, it is important to determine the locations from which the biopsy specimens are taken. Comparison of the severity of AG between different countries should be made using the same biopsy sampling system and grading criteria. Bayerdöerffer et al showed antral predominance of H. pylori colonization, but Genta et al reported more even distribution in the stomach. The authors' patients with NAG and those with antral and mild AG had similar scores of density at the six biopsy sites, whereas those with more extensive AG had the highest score at the middle body on the greater curvature. If only one biopsy specimen should be taken for the diagnosis of H. pylori infection in patients with extensive AG, the middle body of the greater curvature (site 6) would be the most suitable site. Western researchers reported that the grade of chronic and acute inflammation was significantly lower in the body than in the antrum. The authors' findings of patients with NAG were similar to those of Western researchers, but those with atrophy were not. Grades of inflammation and activity in the antrum decrease with the extension of AG. In the authors' patients, the earliest finding of the development of atrophy was found at site 1, and this was the most predominant site of atrophy in patients with extensive AG. Extension of AG into the body was determined by the finding of a biopsy specimen taken at site 3. The earliest finding of the development of intestinal metaplasia was found mostly at the middle body of the lesser curvature and next at the incisura angularis. In patients with extensive intestinal metaplasia, the scores of intestinal metaplasia at site 1 and site 3 were as high as the score at site 2. Site 6 was the last place for the invasion from the extension of AG. If biopsy specimens are taken from site 1, site 3, and site 6, they are enough for the assessment of the extent of AG and intestinal metaplasia. The Updated Sydney System recommended five biopsy sites including the incisura angularis, and its usefulness was coincidentally supported in Japan with a high prevalence of AG seen in results.

Expression and prognostic significance of pepsinogen C in gastric carcinoma

BACKGROUND

In this study we evaluated the expression and clinical significance of pepsinogen C, an aspartic proteinase involved in the digestion of proteins in the stomach, in patients with gastric cancer.

METHODS

Pepsinogen C expression was examined by immunohistochemical methods in a series of 95 gastric carcinomas. The prognostic value of pepsinogen C was retrospectively evaluated by multivariate analysis taking into account conventional prognostic parameters. Follow-up period of patients was 21.4 months.

RESULTS

A total of 25 (26.3%) gastric carcinomas stained positively for pepsinogen C. The percentage of pepsinogen C-positive tumors was higher in well-differentiated (50%) than in moderately differentiated (19.5%) and poorly differentiated (21.9%) tumors (P < .05). Similarly, significant differences in pepsinogen C immunostaining were found between node-negative and node-positive tumors (47.1% vs. 14.7%; P < .001). In addition, statistical analysis revealed that pepsinogen C expression was associated with clinical outcome in gastric cancer patients. Low pepsinogen C levels predicted short overall survival periods in the overall group of patients with gastric cancer (P < .001), and in 71 patients with resectable carcinomas (P < .005). Multivariate analysis according to Cox's model indicated that pepsinogen C immunostaining was an independent predictor of outcome for both overall and resectable gastric cancer patients (P < .05, for both).

CONCLUSIONS

The expression of pepsinogen C in gastric cancer may represent a useful biological marker able to identify subgroups of patients with different clinical outcomes.

Association of Helicobacter pylori-dependent gastritis with gastric carcinomas in young Japanese patients: histopathological comparison of diffuse and intestinal type cancer cases

AIMS

The causal relationship of H. pylori gastric colonization with gastric cancer development has not as yet been fully elucidated. The prevalence of H. pylori infection increases with age in the asymptomatic population in Japan, and reaches a high plateau in those older than 40 years. The objective of this study was to assess the link between H. pylori and gastric carcinomas in patients younger than 40 years.

METHODS AND RESULTS

Detection of H. pylori and assessment of background mucosa based on the Sydney system was performed histopathologically for 40 Japanese gastric cancer cases younger than 40 years and compared with 40 age- and sex-matched controls. H. pylori infection in gastric mucosa was detected significantly more frequently (P < 0.001) in patients with cancer (29/40; 72.5%) than in controls (11/40; 27.5%). Additionally, by histopathological comparison between intestinal (18 cases) and diffuse (70 cases) types of young gastric cancer patients, mucosal atrophy and intestinal metaplasia were found to coexist with acute and chronic inflammation in the background mucosa of both intestinal and diffuse types, being significantly more prevalent than in young controls.

CONCLUSIONS

As well as the high prevalence of H. pylori in young subjects with gastric cancer, it is clear that persistent infection induces mucosal damage, resulting in atrophy and intestinal metaplasia. Thus, acute/chronic gastritis could play an essential role in the early development of neoplasia in the stomach.

Helicobacter pylori infection influences nocturnal gastric acid breakthrough

BACKGROUND

Nocturnal gastric acid breakthrough is defined as night-time periods when gastrin pH falls below 4.0 for greater than 1h during administration of a proton pump inhibitor. This phenomenon is a serious problem for patients who require strict control of their gastric acid secretions.

AIM

To investigate the prevalence of nocturnal gastric acid breakthrough in Japanese subjects during administration of rabeprazole, and to clarify the relationship between Helicobacter pylori infection and nocturnal gastric acid breakthrough.

METHODS

Thirty-one normal male volunteers were examined by ambulatory 24 h gastric pH monitoring four times: without medication, after a morning or an evening dose of 20 mg rabeprazole, and after administration of an H2-receptor antagonist at bedtime, in addition to the morning dose of rabeprazole. H. pylori infection was determined by the 13C-urea breath test and an assay for serum anti-H. pylori antibody.

RESULT

Nocturnal gastric acid breakthrough was observed in 12 patients (39%) after the morning dose of 20 mg rabeprazole. In all cases, nocturnal gastric acid breakthrough was inhibited completely by administration of the H2-receptor antagonist at bedtime. Only one patient with nocturnal gastric acid breakthrough had H. pylori infection.

CONCLUSION

The absence of H. pylori infection appears to be closely related to the occurrence of nocturnal gastric acid breakthrough during dosing with a proton pump inhibitor.

Implications of Helicobacter pylori infection for stomach cancer prevention

Accumulating evidence has implicated Helicobacter pylori, an established cause of chronic gastritis and peptic ulcer, in the etiology of gastric cancer. Control of this infection would reduce the occurrence of chronic gastritis and peptic ulcer and might substantially lower the risk of stomach cancer as well. The public health impact of this infectious agent warrants efforts to identify preventive measures. This paper reviews the evidence linking H. pylori infection to gastric cancer and evaluates the potential for control in high-risk populations. Current obstacles to H. pylori control are discussed, including the link to poor socioeconomic conditions, difficulty in identifying incident cases, lack of natural immunity to reinfection, limited effectiveness of antibiotic therapy in high-prevalence populations, and incomplete knowledge regarding the reservoir of infection, mode of transmission, host susceptibility factors, and the potential for developing an effective vaccine. Worthwhile avenues of research include studies designed to identify modifiable risk factors for acquisition of the infection, modifiable host factors that may increase resistance to chronic infection, more effective antibiotic therapies, and effective vaccines.

Factors that affect results of the 13C urea breath test in Japanese patients

BACKGROUND

The 13C urea breath test (UBT) is considered to be the most accurate way of diagnosing Helicobacter pylori infection. Our objective was to investigate the accuracy of the UBT in Japanese patients and the association of UBT values with histological findings.

MATERIALS AND METHODS

A total of 169 consecutive patients were studied by endoscopy with histology, by serology with IgG antibody and test serum pepsinogen (PG), and by UBT. The association between UBT values and histological findings and the PG I / II ratio were analyzed in H. pylori-positive patients.

RESULTS

Of 169 Japanese patients, 135 were H. pylori-positive on both histology and serology analysis, 27 were H. pylori-negative on both histology and serology analysis, and 7 patients showed differing results. Using a cutoff value of 2.5 per thousand, test sensitivity was 100%, while specificity was 96%. Among the 135 H. pylori-positive patients, a significant relation was observed between UBT value and H. pylori colonization density of the corpus and antrum, neutrophil activity of the antrum, atrophy, and intestinal metaplasia of the corpus in the H. pylori-positive patients. Also, UBT values correlated with the PG I /II ratio. In multivariate analysis, the PG I /II ratio was the most important factor related to UBT values (odds ration [OR], 4. 99; 95% confidence interval, 1.60-15.55).

CONCLUSIONS

The UBT is an accurate method for detecting H. pylori infection in the Japanese population, which shows a high prevalence of atrophic gastritis. Values are affected by H. pylori infection and by the severity of atrophic gastritis.

Comparison of lifestyle and risk factors among Japanese with and without gastric cancer family history

To find specific risk factors of gastric cancer (GC) independent of GC family history (GCFH), 2 studies were conducted using the database of the Hospital-based Epidemiological Research Program at Aichi Cancer Center: (i) a comparison of lifestyles between non-cancer cases with positive and negative GCFH status and (ii) a case-reference investigation of subjects with and without GCFH, treated separately. The first showed no significant variation of GCFH status with regard to smoking, drinking and most food habits. Multivariate analyses in the case-referent studies revealed odds ratios (ORs) for GC associated with habitual smoking of 2.78 (95% CI 1.22-6.28) for those with and 2.74 (95% CI 1.76-4.26) for those without GCFH. In individuals with GCFH, an independently lowered OR (0.52, 95% CI 0.27-0.99) was evident for frequent consumption of raw vegetables, whereas the opposite was noted for pickled vegetables (2. 39, 95% CI 1.28-4.45). No statistically significant interaction was found between GCFH and selected lifestyle items. In conclusion, our results suggest a limited influence of GCFH on risk factors for GC.

Evidence from a nine-year birth cohort study in Japan of transmission pathways of Helicobacter pylori infection

We examined the longitudinal changes of Helicobacter pylori infection within 46 families with children and 48 couples without children living in Japan. The study cohort was monitored from 1986 to 1994. H. pylori status was assessed by the presence of anti-H. pylori immunoglobulin G antibodies. At study entry, H. pylori prevalence in children with positive mothers was 23% versus 5% in children with negative mothers (odds ratio = 5.3; 95% confidence interval = 0.6 to 42.8). Seroconversion (rate of 1.5%/year) was evident only among children living with positive mothers and did not differ among adults living with or without children. These data strongly support the cluster phenomenon of H. pylori infection among families, the key role of the infected mothers in the transmission within families, and the importance of adult-child transmission and not vice versa.

Long-term effect of Helicobacter pylori infection on serum pepsinogens

Serum pepsinogen values are markers of gastric mucosal status and of gastric cancer risk. The effect of Helicobacter pylori infection and sibship size on change of serum pepsinogen values over a seven-year span was investigated. Data from 2584 subjects with phlebotomy were analyzed both in 1989 and in 1996. The subjects were classified by H. pylori serology and sibship size (1 - 3 vs. 4 and more). Pepsinogen I (PG I) to II (PG II) ratio in '96 minus that in '89 was defined as DeltaPG I / II and compared among the groups. DeltaPG I / II was lower and decrease of PG I / II was more frequent among H. pylori-positive subjects than among negative subjects. The difference was owing to a decrease of PG I in all subjects and owing to an increase of PG II in those not younger than 30 years in '89. In H. pylori-positive subjects, those with a larger sibship size showed lower DeltaPG I / II and higher frequency of PG I / II decline. H. pylori infection exerts a reducing effect on PG I / II during the seven-year span. The effect of H. pylori is stronger among those with a larger sibship size, who are expected to have been infected with H. pylori in childhood. Inducing atrophy of gastric mucosa, which is reflected by a decline of PG I / II, may be one of the mechanisms through which H. pylori elevates the risk of gastric cancer.

Comparison of serum antibody titers to Helicobacter pylori lipopolysaccharides, CagA, VacA and partially purified cellular extracts in a Japanese population

We examined the levels of antibody titers against Helicobacter pylori antigens, three types of lipopolysaccharides (LPSs), recombinant CagA antigen, recombinant VacA antigen and partially purified cellular antigens in the sera of Japanese volunteers. The three types of LPSs are LPS carrying the highly antigenic epitope, LPS carrying the weakly antigenic epitope and rough LPS, classified on the basis of antigenicity in humans. IgG titers against all H. pylori antigens tested were significantly different between gastroduodenal patients and healthy adults without H. pylori infection. IgG titers against LPS carrying the weakly antigenic epitope, rough LPS and VacA antigen, as well as IgA titers against the partially purified cellular extract were significantly higher in gastroduodenal patients than in H. pylori-positive healthy adults. However, IgG titers against LPS carrying the highly antigenic epitope, CagA antigen or the partially purified cellular extract showed no significant difference between patients and H. pylori-positive healthy adults. The results indicated that increases in IgG titers against VacA antigen and the weakly antigenic and core epitopes of LPS, and in IgA titer against the partially purified cellular extract, were associated with disease state and may be useful in identifying active infection of H. pylori.

Is autonomic dysfunction a necessary condition for chronic peptic ulcer formation?

BACKGROUND

The relationship between 1/f fluctuation of the heart rate variability and Helicobacter pylori infection was evaluated, in order to clarify whether autonomic nervous dysfunction is a necessary condition for chronic peptic ulcer formation.

METHODS

The subjects were 11 patients with recurrent chronic peptic ulcer and 20 age-matched normal subjects. Holter ECGs were recorded over 24 h, and the 1/f(-x) fluctuation of the heart rate was computed. The 1/f(-x) fluctuation of the heart rate is a novel index of autonomic function that has been shown to reflect a patient's pleasant mood. For 1/f(-x) fluctuation, the slope of the regression line (-x) was determined and cosine fitting of the absolute slope of the regression line over a 24-h period was performed.

RESULTS

For the normal group, the absolute slope of the regression line during daytime and night-time were 0.53 +/- 0.16 and 1.05 +/- 0.18, respectively. For the peptic ulcer group, the corresponding values during daytime and night-time were 0.94 +/- 0.15 and 1.84 +/- 0.18, respectively. The mean value of the cosine curve was 0.76 +/- 0.23 in the normal group and 1.12 +/- 0.25 in the peptic ulcer group. Thus, these values were significantly higher for the latter group than for the former group (P<0.05). No statistically significant difference in H. pylori infection between the two groups was observed.

CONCLUSIONS

Autonomic nervous dysfunction as well as H. pylori infection appears to be a necessary condition for chronic peptic ulcer formation.

Helicobacter pylori infection occurs via close contact with infected individuals in early childhood

BACKGROUND

The manner in which Helicobacter pylori is transmitted is of fundamental importance when considering strategies for its control, yet, to date, the exact mode of transmission remains uncertain.

METHODS

The seroprevalence of H. pylori in a relatively isolated rural town in Japan (A-town) was examined to analyse the H. pylori infection route. The immunoglobulin G antibodies against H. pylori in 1684 subjects who had received public health examinations in A-town were determined with an enzyme-linked immunosorbent assay. The seroprevalence was compared in five areas according to the water source. The possibility and frequency of intrafamilial infection was analysed by comparing the seroprevalence among family members residing in the same home.

RESULTS

The seroprevalence of H. pylori did not differ significantly between the five areas examined. Seropositivity was significantly more common in the children whose mothers were seropositive (45.0%, 27/60) than in the children whose mothers were seronegative (10.0%, 2/20; odds ratio (OR) = 7.36, P = 0.0036, 95% confidence interval (CI) = 1.57-34.59). Seropositivity was significantly more common in the children whose older siblings were seropositive (55.0%, 22/40) than in the children whose older siblings were seronegative (23.5%, 20/85; OR = 3.97, P = 0.00051, 95% CI = 1.79-8.84). There was no significant relationship in seroprevalence between children and fathers, grandchildren and grandfathers, grandchildren and grandmothers, or within couples. Seropositivity was significantly more common in the adolescents who had attended a nursery school (44.4%, 20/45) than in the adolescents who had not attended a nursery school (25.6%, 109/426) (OR = 2.33, P = 0.0070, 95% CI = 1.24-4.36).

CONCLUSIONS

The acquisition of H. pylori infection occurs by close contact with infected individuals in early childhood, especially via contact with infected mothers and other infected children.

Functional dyspepsia and Helicobacter pylori infection: a recent consensus up to 1999

With accumulated evidence for a close relationship between Helicobacter pylori infection and many gastric disorders, the idea that this infection may invoke dyspeptic symptoms appears realistic. If curative therapy for H. pylori can bring about relief of symptoms in these patients, we would possess a new therapeutic tool for functional dyspepsia. Although there have been many clinical trials on this issue, the benefits of H. pylori treatment have been controversial. However, several large-scale clinical studies have been very recently published, and suggest a specific direction on this clinical question. From these results, the current consensus is that H. pylori infection does not directly affect symptoms in patients with functional dyspepsia. However, most clinical trials have been performed on Western populations, and there are few reports from Asian countries. Our recent study on the Japanese population also supported the consensus, that is, a negative relationship between H. pylori infection and symptoms in functional dyspepsia patients.

Helicobacter pylori infection is a major risk factor for gastric carcinoma in young patients

BACKGROUND

Helicobacter pylori has been established as a risk factor for gastric carcinoma (GCa). Since before the discovery of H. pylori, atrophic gastritis and intestinal metaplasia have been linked to GCa, especially the intestinal-type tumor. The prevalence of H. pylori infection and atrophic gastritis increase with age. Thus, analysis of H. pylori infection in young patients with GCa could help clarify the role of this bacterium in the development of GCa. Accordingly, we investigated the relationship between H. pylori infection, GCa, and histologic gastritis in patients less than 30 years old.

METHODS

Fifty GCa patients less than 30 years (mean, 26.4 years) and 100 sex- and age-matched controls (mean, 26.8 years) were examined for the presence of H. pylori infection and histologic gastritis.

RESULTS

The prevalence of H. pylori infection was significantly higher in GCa patients than in controls (94% versus 40%, P < 0.01). Its prevalence was not associated with tumor location, tumor stage, or histologic type. Gastritis, atrophy, and intestinal metaplasia significantly increased the risk of GCa. By means of multiple logistic regression analysis, the odds ratio for the risk of GCa in H. pylori-positive subjects was found to be 23.5 (95% confidence interval, 6.84-80.7).

CONCLUSIONS

We confirmed a strong association between H. pylori infection and GCa in young patients. Along with H. pylori infection, histologic gastritis might play an important role in the pathogenesis of GCa in these patients.

Negative association between Helicobacter pylori infection and reflux esophagitis in older patients: case-control study in Japan

BACKGROUND

Recent studies have clarified a close association between H. pylori infection and gastritis, peptic ulcer disease, and gastric cancer, but there is little information concerning the relationship between H. pylori infection and reflux esophagitis (RE). We investigated the relationship between H. pylori, RE, and corpus gastritis.

SUBJECTS AND METHODS

Ninety-five patients with RE and 190 sex- and age-matched asymptomatic healthy controls demonstrating no localized lesions in the upper GI tract were studied and evaluated for H. pylori infection, histologic gastritis, serum gastrin, and pepsinogens (PGs).

RESULTS

H. pylori infection was significantly lower in RE patients than in asymptomatic controls (41% vs. 76%, p <.01). Histologic gastritis of both the antrum and corpus was significantly less frequent (antrum; p <.01, corpus; p <. 01), and serum levels of PGI and the PG I/II ratio were significantly higher in RE patients than in controls (PGI; p <.05, PG I/II ratio; p <.01). When the subjects were divided into two age groups (59 years of age and younger and 60 years of age and older), a significant difference was found only among patients over 60 years of age (29% vs. 85%, p <.01). Among subjects in this age group, gastritis in both the antrum and corpus were significantly milder in RE patients than in controls. Although the prevalence of H. pylori infection was similar between the two groups of patients under 59 years of age, corpus gastritis was significantly milder in patients than in controls (p <.05).

CONCLUSIONS

A significantly low prevalence of H. pylori infection was found in RE patients over 60 years of age but not in those under 59 in comparison with sex- and age-matched controls. The relative lack of corpus gastritis might play a role in the pathogenesis of RE in our population through preservation of the acid secretion area.

Relationship between Helicobacter pylori infection and smoking and drinking habits

BACKGROUND

Helicobacter pylori is a major cause of various gastroduodenal diseases. Some risk factors related to H. pylori infection have been reported; however, studies on the relationship between H. pylori infection and smoking or drinking habits have given conflicting results. In the present study, these relationships were investigated by collecting sera and information from 8837 subjects.

METHODS

Serum H. pylori immunoglobulin G antibody was measured by an enzyme-linked immunoassay. In addition to sex and age, information on smoking and drinking habits was collected by questionnaire. Age- and sex-adjusted odds ratios (95% confidence interval) of smoking and alcohol consumption were calculated for H. pylori seropositivity using logistic regression models.

RESULTS

Current smokers had a 0.82 (0.74-0.91)-fold greater risk of H. pylori seropositivity than those who had never smoked. Current cigarette consumption showed a dose-dependently negative association with H. pylori seropositivity, and the association between smoking and H. pylori infection was strong in younger subjects. Current drinkers had a 0.88 (0.79-0.98)-fold greater risk of H. pylori seropositivity than those who had never drunk alcohol. The volume of alcohol consumed showed a negative association with H. pylori seropositivity.

CONCLUSIONS

In the current study, smoking was negatively associated with H. pylori infection. The risk of H. pylori seropositivity decreased linearly with cigarette consumption per day. Increased gastric acidity in the stomach through smoking may be a cause of the dose-dependently negative association between H. pylori and smoking. Drinking was negatively and dose-dependently associated with H. pylori positivity, although the effect of drinking was weaker than that of smoking.

Helicobacter pylori infection among offspring of patients with stomach cancer

BACKGROUND & AIMS

A positive family history is associated with an increased risk of stomach cancer. We compared the prevalence of Helicobacter pylori infection, a known risk factor for stomach cancer, between subjects with and without parental history of stomach cancer to evaluate a potential role of H. pylori infection in familial aggregation of stomach cancer.

METHODS

A total of 1351 men and women aged 30-74 years who participated in the German Health and Nutrition Survey conducted in the western part of Germany in 1987-1988 were included in the study. Detailed information on sociodemographic factors, nutritional factors, and parental history of cancer was obtained by standardized interviews. Serum samples were analyzed for immunoglobulin G antibodies against H. pylori by enzyme-linked immunosorbent assay.

RESULTS

The prevalence of H. pylori infection was much higher (69%) among subjects with a parental history of stomach cancer than among other subjects (44%). This association persisted after control for potential confounders by multiple logistic regression (adjusted odds ratio, 2.7; 95% confidence interval, 1.3-5.9), and was particularly strong among subjects below age 55 (adjusted odds ratio, 5.1; 95% confidence interval, 1.6-16.1).

CONCLUSIONS

These results suggest that familial aggregation of stomach cancer may be explained at least partly by familial clustering of H. pylori infection.

Helicobacter pylori infection inhibits reflux esophagitis by inducing atrophic gastritis

OBJECTIVE

Although it is widely accepted that Helicobacter pylori (H. pylori) infection is an important cause of atrophic gastritis, few studies have examined the relationship between H. pylori-induced atrophic gastritis and the occurrence of reflux esophagitis. The present study was aimed to examine the relationship between H. pylori infection, atrophic gastritis, and reflux esophagitis in Japan.

METHODS

A total of 175 patients with reflux esophagitis were compared with sex- and age-matched 175 control subjects. Diagnosis of H. pylori infection was made by gastric mucosal biopsy, rapid urease test, and serum IgG antibodies. Severity of atrophic gastritis was assessed by histology and serum pepsinogen I/II ratio.

RESULTS

H. pylori infection was found in 59 (33.7%) patients with reflux esophagitis, whereas it was found in 126 (72.0%) control subjects. The grade of atrophic gastritis was significantly lower in the former than in the latter. Among the H. pylori-positive patients, atrophic gastritis was milder in the patients with reflux esophagitis than in the patients without it.

CONCLUSIONS

These findings suggest that most cases of reflux esophagitis in Japan occur in the absence of H. pylori infection and atrophic gastritis, and it may also tend to occur in patients with milder gastritis even in the presence of H. pylori infection. Therefore, H. pylori infection may be an inhibitory factor of reflux esophagitis through inducing atrophic gastritis and concomitant hypoacidity.

Association between infections with CagA-positive or -negative strains of Helicobacter pylori and risk for gastric cancer in young adults. Research Group on Prevention of Gastric Carcinoma Among Young Adults

OBJECTIVE

We assessed the association between infection with CagA-positive and -negative Helicobacter pylori and the risk of gastric cancer in young adults.

METHODS

CagA IgG antibodies were measured in sera of subjects participating in a case-control study in Japan. The study subjects were 103 gastric cancer patients <40 yr of age, 100 inpatients with benign diseases, and 101 screenees younger than age 43 yr.

RESULTS

Compared with the H. pylori-negative/CagA-negative (H. pylori-/CagA-) group, both the H. pylori-positive/CagA-negative (H. pylori+/CagA-) group and the H. pylori-positive/CagA-positive (H. pylori+/CagA+) groups showed elevated odds ratios for intestinal-type, diffuse-type, early, advanced, proximal, and distal gastric cancers. All the relationships were significant except for the H. pylori+/CagA- group in relation to proximal cancer. The overall odds ratios (95% confidence intervals) for gastric cancer in the H. pylori+/CagA- and the H. pylori+/CagA+ groups were 15.0 (6.4, 35.2) and 14.6 (6.7, 31.9), respectively. Between these two groups, no significant difference was observed in risks for intestinal-type, diffuse-type, early, advanced, proximal, or distal gastric cancer.

CONCLUSIONS

In those <40 yr of age, it is concluded that both CagA-positive and CagA-negative H. pylori infections are related to risks of intestinal-type, diffuse-type, early, advanced, and distal gastric cancers.

Prevalence of non-ulcer dyspepsia in the Japanese population

BACKGROUND

Non-ulcer dyspepsia (NUD) is one of the most frequently encountered disorders in general practice in Western countries. The prevalence of this disorder in the Japanese, however, has not been fully investigated. This study is designed to clarify the characteristics and prevalence of dyspepsia in the Japanese.

METHODS

The subjects were 1139 people who visited our institutes for their annual medical check up for gastric cancers. After routine medical examination, all subjects were asked standardized questions in order to check for the presence of any symptoms suggesting dyspepsia.

RESULTS

The results of the study showed that dysmotility-like dyspepsia, characterized by the presence of nausea, fullness and early satiety, is the most frequently observed dyspepsia in Japanese and that this type of dyspepsia decreases with age. Ulcer-like dyspepsia, which is the major type of dyspepsia in Western countries, is the least frequently experienced dyspepsia in the Japanese.

CONCLUSIONS

This study clarified that NUD is also one of the most prevalent disorders in the Japanese, although its characteristics may be somewhat different from those in Western countries.

[Influence on diagnosis of Helicobacter pylori infection in 13C urea breath test of existence of dead space gas]

The 13C-urea breath test is a noninvasive analysis for the detection of Helicobacter pylori infection and is valuable for judging the effects of antimicrobial treatment. Up to date the most popular technique for 13C-urea breath test: UBT, is performed by collecting expired gas into an aluminum bag, but the result is considered to be influenced in the diagnosis of Helicobacter pylori infection by the existence of anatomical dead space gas. We therefore introduced a new technique to measure 13CO2 and 12CO2 continuously during expiration, identified the correct alveolar gas, and excluded the effect of anatomical dead space. Subjects were 127 males and 8 females. We compared the diagnostic accuracy of these aluminum bag and continuous measurement methods. We adopted serological IgG positive and barium-meal study positive cases as a gold standard for the diagnosis. Diagnostic accuracy by continuous measurement was superior to that by the aluminum bag method. We should pay attention to the existence of anatomical dead space for accurate diagnosis. Continuous measurement is important in the collection of end tidal expired gas in order to make an accurate diagnosis.

Helicobacter pylori in the natural environment

The presence of Helicobacter pylori (H. pylori) in the natural environment has been demonstrated in a number of studies. However, its route of infection into humans is unknown. To study this further, we attempted to detect H. pylori in the natural environment in a region of Japan with a high infection rate. Tap and well water and field soil samples were collected from around the residences of subjects who had participated in an epidemiological survey in 1996. Samples of water from rivers and ponds, and specimens of flies and cow faeces were collected in the region. DNA was extracted from the water, field soil and faecal samples after selective collection of H. pylori by the immunomagnetic-bead separation technique. H. pylori-specific DNA was detected in water, field soil, flies and cow faeces by nested polymerase chain reaction (PCR), and the ureA partial sequences of the PCR products were aligned. The nucleotide sequences of the samples amplified by PCR were highly homologous (96-100%) with the H. pylori sequence in the GenBank database and the H. pylori-specific DNA sequences were highly homologous with each other. These findings suggest the existence of H. pylori in the natural environment and a possible transmission route.

Noninvasive evaluation of Helicobacter pylori therapy: role of fasting or postprandial gastrin, pepsinogen I, pepsinogen II, or serum IgG antibodies

OBJECTIVE

We evaluated the potential value of a change in serum IgG antibodies, fasting or meal-stimulated gastrin levels, and pepsinogen I (PGI) or pepsinogen II (PGII) levels for identifying Helicobacter pylori (H. pylori) status after antibiotic therapy.

METHODS

A total of 32 men and one woman with peptic ulcer disease and documented H. pylori infection were enrolled. Fasting and 30-min postprandial blood samples were obtained at 0, 2, 7, 11, 17, 23, 27, and 39 wk of the study and were analyzed for the factors evaluated.

RESULTS

Treatment was successful in 25 patients and failed in seven. Serum IgG antibodies, meal-stimulated gastrin, and both fasting and meal-stimulated pepsinogen I and II levels fell throughout the study, and pepsinogen I:II ratios increased in those whose infection was cured. The mean levels at wk 0 versus wk 7 were: fasting gastrin (fmol/ml) 12.4 and 11, meal-stimulated gastrin 26.5 and 15.4, PGI (ng/ml) 83.7 and 59, PGII (ng/ml) 24.5 and 13.6, PGI/PGII 3.5 and 4.7, and enzyme-linked immunosorbent assay value 4.8 and 4.55. The sensitivity, specificity, and positive and negative predictive values for the data analyzed using different percent changes (e.g., 80%, 50%, and 20%) were calculated. The specificity and sensitivity remained <80% at all time points.

CONCLUSIONS

Despite a significant fall in serum markers of H. pylori infection in groups of individuals, no marker tested could be used to reliably determine posttherapy H. pylori status for individual patients.

In vitro and in vivo activities of tea catechins against Helicobacter pylori

The catechin epigallocatechin gallate showed the strongest activity of the six tea catechins tested against Helicobacter pylori (MIC for 50% of the strains tested, 8 microg/ml). It had bactericidal activity at pH 7 but not at pH </=5.0. In infected Mongolian gerbils, H. pylori was eradicated in 10 to 36% of the catechin-treated animals, with significant decreases in mucosal hemorrhage and erosion. Tea catechins, therefore, may have therapeutic effects on H. pylori infection.

Changes in seroepidemiological pattern of Helicobacter pylori and hepatitis A virus over the last 20 years in Japan

OBJECTIVE

The age groups most susceptible to infection and the mode of transmission of Helicobacter pylori (H. pylori) are not yet clear. To contribute to a better understanding of this disease, this study was undertaken to evaluate changes in the seroepidemiological pattern of H. pylori in a group of Japanese people over the last 20 yr sampled in 1974, 1984, and 1994 in comparison with that of the hepatitis A virus (HAV), which was used as a marker of the fecal-oral route of transmission.

METHODS

A total of 1015 serum samples were obtained from the National Institute of Infectious Diseases in Tokyo. All of these samples were from healthy persons aged 0-89 yr (442 male and 573 female; median age 35.6 yr), living in seven prefectures in the central part of Japan in 1974, 1984, and 1994. All serum samples were assayed for H. pylori IgG by means of enzyme-linked immunosorbent assay (ELISA). Further, anti-HAV antibodies were assayed by blocking ELISA in the same samples. We investigated the prevalence of H. pylori and HAV for all ages, and the positive rate of H. pylori for infants and children separately.

RESULTS

The overall prevalence of H. pylori antibodies was 72.7% (CI 95%, 68.0-77.3) in 1974, 54.6% (CI 95%, 49.1-60.0) in 1984 and 39.3% (CI 95%, 34.1-44.4) in 1994. That of HAV was 57.7% (CI 95%, 52.5-62.8) in 1974, 41.7% (CI 95%, 36.3-47.0) in 1984, and 23.4% (CI 95%, 18.9-27.8) in 1994. The prevalence of both H. pylori and HAV was found to increase with age, whereas there have been clear cohort shifts in the seroepidemiological patterns of both infections over the last 20 yr in Japan. This study shows that there is a slight similarity in the concordance of positive and negative populations between H. pylori and HAV. However, it was very difficult to determine the concordance between H. pylori and HAV infection in this study.

CONCLUSIONS

Our data strongly suggest that the highest infection rates for both H. pylori and HAV occur among infants and children in Japan. This study provides evidence that H. pylori and HAV may share a common mode of transmission but that changes in environmental conditions make this very difficult if not impossible to prove with seroepidemiological data.

In vitro and in vivo activities of tea catechins against Helicobacter pylori

The catechin epigallocatechin gallate showed the strongest activity of the six tea catechins tested against Helicobacter pylori (MIC for 50% of the strains tested, 8 microg/ml). It had bactericidal activity at pH 7 but not at pH </=5.0. In infected Mongolian gerbils, H. pylori was eradicated in 10 to 36% of the catechin-treated animals, with significant decreases in mucosal hemorrhage and erosion. Tea catechins, therefore, may have therapeutic effects on H. pylori infection.

Helicobacter pylori and gastric cancer: what are the benefits of screening only for the CagA phenotype of H. pylori?

BACKGROUND

Strains of Helicobacter pylori that express the CagA protein are associated with a threefold increased gastric cancer risk as compared to H. pylori strains that do not express CagA. Screening and treatment only for CagA antibodies should target those individuals at highest gastric cancer risk while reducing the number of patients requiring antibiotics. We compared the costs and benefits of screening asymptomatic 50-year-old individuals for CagA, screening for all H. pylori strains, and no screening, both in the United States and abroad.

MATERIALS AND METHODS

We employed Markov cost-effectiveness analysis using data from randomized, case-control, and cohort studies.

RESULTS

In the United States, CagA screening would result in 1.5 million fewer antibiotic treatments but would prevent 1,400 fewer gastric cancers than would screening for all H. pylori. The incremental cost-effectiveness of CagA screening is $23,900 per life-year gained; for H. pylori screening, it is $25,100. Screening in countries with epidemiological characteristics similar to those of Colombia, Finland, and Japan costs less than $5,000 per life-year gained, and the difference between CagA and H. pylori screening is smaller than that in the United States.

CONCLUSIONS

Screening only for CagA-positive H. pylori is not substantially better than is screening for all H. pylori, either in the United States nor abroad. Screening is substantially more cost-effective outside the United States. Whether population screening is justified, however, is uncertain pending conclusive data regarding the reduction in gastric cancer risk from antibiotics.

Gastric ulcer formation after the Hanshin-Awaji earthquake: a case study of Helicobacter pylori infection and stress-induced gastric ulcers

BACKGROUND

Both Helicobacter pylori (H. pylori) infection and various stresses are known to induce peptic ulcer disease of the upper gastrointestinal tract. However, the pathogenetic relationship between the two factors has not yet been clarified. We conducted a case-control study to examine whether H. pylori infection played a role in the development of gastric ulcer (GU) induced by life-event stresses that were experienced after the Hanshin-Awaji earthquake.

MATERIALS AND METHODS

Serum samples from patients in the devastated area who developed GUs during the 2 months following the Hanshin-Awaji earthquake and those from GU patients in the same area during the corresponding period of the previous year, and from gender-, age- and institute-matched ulcer-free controls were tested for the presence of the H. pylori IgG antibody.

RESULTS

A significant association between H. pylori infection and the development of GU in uninjured patients was observed in all sets [matched odds ratio (OR) = 3.23, 95% confidence interval: 1.95-5.35]. Moreover, the prevalence of H. pylori infection in patients who developed GUs after the earthquake was not different from that for GU patients in the previous year. In contrast, there was no association between H. pylori infection and the development of GU in the physically injured patients after the earthquake.

CONCLUSIONS

H. pylori infection may play an important role in the development of GUs that are induced by emotional life-event stresses.

Seroprevalence of Helicobacter pylori infection in Malaysian children: evidence for ethnic differences in childhood

OBJECTIVES

To determine the prevalence of Helicobacter pylori (H. pylori) in healthy Malaysian children and to discover whether differences exist among children of different races.

METHODS

Serum samples from asymptomatic children tested for H. pylori seropositivity using an ELISA test.

RESULTS

Five hundred and fourteen healthy urban Malaysian children aged 0.5 to 17 (mean 5.9) years from three different racial groups had their blood tested for H. pylori antibodies. The overall prevalence was 10.3%. There was no significant difference in the prevalence of infection between boys and girls, but a significant rise was noted with increasing age (P = 0.009). Seropositivity was most common in the Indians and lowest in the Malays (P = 0.001). Father's level of education did not affect the child's rate of H. pylori seropositivity.

CONCLUSION

The prevalence of H. pylori seropositivity among asymptomatic urban Malaysian children is lowest in Malays. Intermediate in Chinese and highest in Indians. The racial differences found in children are consistent with those found in Malaysian adults.

CagA and cytotoxicity of Helicobacter pylori are not markers of peptic ulcer in Japanese patients

BACKGROUND

The infection with cagA-positive Helicobacter pylori strains is reported to be associated with peptic ulcer disease in developed countries, but it is controversial in Asia. To investigate the relationship between the virulence factors of H. pylori and peptic ulcer disease in Japan, we compared these between ulcer and nonulcer patients.

MATERIALS AND METHODS

Seventy-four strains of clinically isolated H. pylori obtained from 22 gastric ulcer (GU), 23 duodenal ulcer (DU), and 29 chronic gastritis (CG) patients were studied. The presence of vacA and cagA gene was examined by polymerase chain reaction method using two different primer sets. We evaluated the proliferation-inhibiting and lethal cytotoxicity of culture supernatants using the alamarBlue assay.

RESULTS

The vacA gene was identified in all strains by the original primers. S1 strains were found in 90.9% (20/22) from GU, 95.7% (22/23) from DU, and 96.6% (28/29) from CG patients. The prevalence of cagA gene determined by the first, and second primers was 90.9% (20/22), 90.9% (20/22) in strains from GU, 87.0% (20/23), 91.3% (21/23) from DU, and 86.2% (25/29), 89.7% (26/29) from CG patients, respectively. The supernatant showed cytolethal effect in 95.5% (21/22) of strains from GU, in 100% (23/23) from DU, and in 93.1% (27/29) from CG patients. There was no significant difference in the prevalence of the virulence factors between H. pylori strains isolated from patients with peptic ulcers and those with chronic gastritis.

CONCLUSIONS

These results indicate that cagA gene status and the proliferation-inhibiting and lethal cytotoxicity of supernatant are not reliable markers of ulcerogenicity of H. pylori in Japanese patients.

Helicobacter pylori seropositivity in patients with severe neurologic impairment

The objective of this study was to assess the prevalence of Helicobacter pylori seropositivity in institutionalized patients with severe neurologic impairment. Anti-H. pylori immunoglobulin G antibody in serum was measured in 196 institutionalized Japanese patients using enzyme linked immunosorbent assay, taking an antibody level >50 units/ml as evidence of H. pylori seropositivity. Patient age pattern and duration of institutionalization were examined for the relationships with H. pylori seropositivity. We also examined for seroconversion indicating new H. pylori infection in initially negative patients 1 year later. Positivity for H pylori infection among institutionalized patients was also compared with positivity among patients living at home. H. pylori seropositivity was present in 81.1% of subjects. Prevalence of H. pylori seropositivity increased with both age and duration of institutionalization. The serum level of anti-H. pylori immunoglobulin G antibody in patients over 20 years old was consistently high, approximately twice that of subjects less than 10 years of age. Of 38 patients initially negative for H. pylori infection, 18 (47.4%) had become positive at 1 year. H. pylori seropositivity was significantly more prevalent among institutionalized patients than among patients living at home (P < 0.0001). This study confirms that high H. pylori seropositivity rates are found among institutionalized patients with severe neurologic impairment. Our observations suggest person to person transmission, with fecal to oral, salivary secretion and respiratory droplet routes possibly being important pathways.

Antibody against Helicobacter pylori CagA and VacA and the risk for gastric cancer

AIM

Helicobacter pylori is associated with gastric cancer. Our aim was to investigate whether CagA or VacA seropositivity provides additional risk for gastric cancer.

METHODS

Sera from 110 gastric cancer patients were sex and aged matched with asymptomatic controls. H pylori status was determined by IgG enzyme immunoassay (HM-CAP EIA); CagA status was assessed by enzyme linked immunosorbent assay (ELISA) (OraVax) and immunoblotting (Chiron), and VacA status by immunoblotting using recombinant proteins as antigens.

RESULTS

H pylori infection was associated with an increased risk of gastric cancer (odds ratio (OR) = 2.19, 95% confidence interval 1.17 to 4.1). Subgroup analysis showed a significant association with intestinal type (OR = 2.94, 1.35 to 6.41), distal type (OR = 2.97, 1.39 to 6.33), early gastric cancer (OR = 3.74, 1.54 to 9.06), and age < or = 55 years (OR = 8.33, 2.04 to 34.08), but not with diffuse type (OR = 0.83), proximal type (OR = 1.0), advanced gastric cancer (OR = 1.13), or age > 55 years (OR = 1.40). Serum CagA IgG and VacA antibody positivity was present in similar proportions in patients with and without cancer, with no significant differences in histological classification, clinical stage, or location (p > 0.3).

CONCLUSIONS

H pylori infection causes chronic gastritis and is associated with the development of gastric cancer. Neither CagA nor VacA seropositivity added additional information or stratification.

The role of endoscopic findings for the diagnosis of Helicobacter pylori infection: evaluation in a country with high prevalence of atrophic gastritis

BACKGROUND

This study examines endoscopic findings in the diagnosis of Helicobacter pylori (H. pylori) in the Japanese population.

MATERIALS AND METHODS

The endoscopic findings (including gastric fold findings and degree of atrophy by the Kimura-Takemoto classification system), histologic severity of inflammation, and glandular atrophy were assessed according to the Sydney system in 642 patients (419 men; 223 women; mean age 43.5 years, range 13-86). H. pylori infection was evaluated by Giemsa staining and serum IgG antibodies.

RESULTS

391 of 642 patients (60.9%) were diagnosed as having endoscopic gastritis. Of the 391 patients with endoscopic gastritis, 318 (82.6%) had histologic gastritis and 310 (79.3%) had H. pylori infection. Of the 251 patients with endoscopically normal stomachs, 43 (17.1%) had histologic gastritis and 32 (12.7%) had H. pylori infection. Atrophic gastritis was the most prevalent finding (56.3%) among those with endoscopic gastritis. The prevalence of H. pylori infection in patients with atrophic gastritis (92.7%) and rugal hyperplastic gastritis (92.3%) was significantly higher than in those with other types of gastritis or with a normal stomach (12. 7%). A markedly high prevalence of H. pylori infection was found in subjects with tortuosity, hyperrugosity, and/or hyporugosity of the gastric folds.

CONCLUSIONS

The accurate endoscopic assessment of gastritis according to the Sydney system along with gastric fold findings and the endoscopically identified extent of gastric atrophy are valuable indicators for determining H. pylori infection and histologic gastritis in the Japanese population.

Helicobacter pylori and gastric cancer

Infection with Helicobacter pylori is now recognized as the primary cause of peptic ulcers and their recurrence. Compelling evidence has also been found linking H. pylori infection to gastric cancer, the second most common cancer in the world. Given the high rate of patient morbidity and mortality associated with gastric cancer, any method by which one can reduce the occurrence of the disease or increase its early detection is desirable. The strong correlation with H. pylori infection and the current availability of easily administered tests for the detection of the pathogen argue for screening at least those individuals with a family history of gastric cancer or other risk factors. This article reviews the association between H. pylori and gastric cancer and the pathologic changes that the infection produces in the gastric mucosa, as well as the cost-effectiveness of universal testing and eradication of the infection in H. pylori-positive individuals to reduce gastric cancer.

Helicobacter pylori infection in the remnant stomach after gastrectomy: with special reference to the difference between Billroth I and II anastomoses

Helicobacter pylori infection is associated with many gastric diseases, such as peptic ulcer and gastric cancer. We examined the remnant stomach for H. pylori infection after gastrectomy for gastric cancer or peptic ulcer between October 1992 and July 1997. H. pylori DNA in the gastric juice of 109 patients [mean age 62.4 years, male/female 78/31, gastrectomy for gastric cancer 83/peptic ulcer 26, Billroth I (BI) anastomosis 72/Billroth II (BII) 37, mean postoperative interval 6.0 years] was amplified by PCR and detected by Southern blot hybridization. The serum of 135 patients was assayed by ELISA for IgG antibody against H. pylori (mean age 61.8 years, male/female 99/36, gastrectomy for gastric cancer 111/peptic ulcer 24, BI anastomosis 93/BII 42, mean postoperative interval 5.4 years). H. pylori was positive in 68/109 (62.4%) by PCR and 113/ 135 (83.7%) by ELISA. H. pylori cytotoxin gene cagA, a H. pylori virulence factor gene, was found in 15/16 (93.8%) cases by PCR. A significant difference in H. pylori positivity by PCR was found according to the type of anastomosis (BI vs. BII) but not according to age group, sex, disease (cancer or ulcer), or postoperative interval by PCR and ELISA. BII anastomosis was followed by a significantly lower rate of H. pylori infection (17/37; 45.9%) than BI anastomosis (51/72; 70.8%; p=0.01) according to the results of PCR. Moreover, some patients with BII anastomosis (3/8; 37.5%) showed positive to negative seroconversion for H. pylori infection after the operation (mean 2.47 years) according to the results of ELISA, but this phenomenon was not observed in patients with BI (0/12) anastomosis. This may reflect the role of bile reflux, which is more common in BII than BI, because bile reflux interferes with colonization by H. pylori.

The prevalence and related symptomatology of Helicobacter pylori in children with recurrent abdominal pain

The aim of the study was to assess and compare the IgG seroprevalence of H. pylori in children with recurrent abdominal pain with healthy children and to investigate the related symptoms. IgG antibodies against low-molecular weight H. pylori antigens were assessed in 438 children with recurrent abdominal pain and in 91 healthy controls. Sera with an ELISA unit-value above the cut-off level were confirmed by Western immunoblot. Only seropositive children with recurrent abdominal pain were examined by an oesophago-gastro-duodenoscopy. Symptomatology was recorded according to the localization of the abdominal pain, presence of pyrosis, nocturnal pain, relation of pain to meals and bowel irregularities. The seroprevalence was 21% (95% CI: 17-25%) in the children with recurrent abdominal pain and 10% (95% CI: 5-18%) in the healthy controls (p = 0.30). In seropositive children with RAP H. pylori was found in 46/66 by culture and histology. The presence of H. pylori was significantly associated with active or inactive chronic gastritis. The presence of H. pylori was associated with both parents being born in a country with a high prevalence and a low social class. Helicobacter pylori-positive children had more often pain related to meals than the H. pylori-negative children. No differences among the two groups were seen according to the levels of haemoglobin, leucocytes, thrombocytes, weight and height. In conclusion, the seroprevalence of H. pylori is comparable in children with recurrent abdominal pain and healthy children. No specific symptomatology was seen in H. pylori-positive children with RAP.

No difference in seroprevalences of Helicobacter pylori infection between patients with pulmonary tuberculosis and those without

A previous article reported a possible relationship between a history of tuberculosis and Helicobacter pylori infection. Epidemiologic similarities exist between the two infections: Mycobacterium tuberculosis and H. pylori are transmitted from person to person and the risk of acquiring them is elevated in underprivileged environment. This study was conducted to investigate the relationship between the two infections. Serum concentrations of anti-H. pylori IgG antibody were measured in 40 tuberculosis inpatients on antituberculosis chemotherapy for no more than 3 months (group I; 52.4 +/- 21.4 years of age), 43 tuberculosis inpatients on it for more than 3 months (group II; 57.3 +/- 16.3 years), and 60 nontuberculosis outpatients (control subjects; 55.9 +/- 16.7 years). H. pylori seropositivities were similar among control subjects (73.3%), group I (65%), and group II (69.8%). The difference in the antibody concentrations was significant between control subjects and group I (353.7 +/- 321.2 vs. 176.5 +/- 197.9 U/ml) but was not significant between control subjects and group II (353.7 +/- 321.2 vs. 229.9 +/- 249.5 U/ml). The seroprevalences may not be different between patients with pulmonary tuberculosis and those without, and antituberculosis therapy may not decrease the antibody concentrations.

Relationship of vacA genotypes of Helicobacter pylori to cagA status, cytotoxin production, and clinical outcome

BACKGROUND

Mosaicism in vacA alleles with three distinct families of vacA signal sequences (s1a, s1b and s2) and two distinct families of middle region alleles (m1 and m2) has been reported. It was suggested that the vacA s1a genotype was closely associated with duodenal ulcer disease and with high cytotoxin production. The aim of this study was to evaluate the role of vacA genotyping with respect to gastric inflammation and injury, cytotoxin activity, and clinical presentation.

METHODS

H. pylori from patients with gastritis, peptic ulcer disease, or gastric cancer were characterized by vacA typing by polymerase chain reaction (PCR) and DNA sequencing. In vitro cytotoxin activity was assessed by vacuolation assay using Vero cells as well as with Hela cells.

RESULTS

Four hundred ninety-one strains were tested. vacA genotype s1a/m1 was present in more than 95% of strains independent of presentation with gastritis, peptic ulcer, or gastric cancer. No vacA genotype was associated with high average cytotoxin activity. The s2/m2 isolates had low or absent cytotoxin activity. All cagA negative strains (n = 18) were s1a strains and both s2/m2 strains were cagA positive. One strain that was a recombinant of m1 and m2 strains was identified and had low cytotoxin activity. The nucleotide and amino acid sequences between original m1 strains and Japanese m1 strains (new m1 strains) were about 85% and 81%, respectively. Strains with the new m1 genotype had nucleotide and amino acid sequences similarity of more than 96%. There was no difference in cytotoxin activity between strains with the Western type m1 and the new type m1 genotype.

CONCLUSION

In this as in other reported studies ( approximately 1500 patients overall) vacA genotype was strongly but not exclusively associated with the presence of cagA. Overall, the studies did not support a role for vacA genotyping in relation to cytotoxin activity, virulence, histologic finding, or risk of a particular H. pylori disease. vacA genotype s1 is likely to be a surrogate marker for the presence of the cag pathogenicity island.

Helicobacter pylori reinfection rates in children after eradication therapy

BACKGROUND

There are few studies of Helicobacter pylori reinfection in childhood. In the current study the reinfection rate of H. pylori and ulcer recurrence were investigated during a follow-up period of 12 months or more in children who had undergone eradication therapy.

METHODS

Twenty-seven patients aged 5 to 16 years (6 with gastric ulcer, 13 with duodenal ulcer, and 8 with nodular gastritis) were studied. Biopsy-based H. pylori tests performed 1 to 2 months after eradication therapy demonstrated that eradication was successful in 23 patients (5 with gastric ulcer, 11 with duodenal ulcer, and 7 with nodular gastritis) and unsuccessful in 4 (1 with gastric ulcer, 2 with duodenal ulcer, and 1 with nodular gastritis). Twenty-three successfully treated patients were observed for a mean of 22 months (a total of 42.2 patient years of follow-up). To assess H. pylori status, all 23 patients underwent a 13C-urea breath test 1 year after eradication therapy. If the test result was negative, the patients underwent the follow-up test once every year thereafter. In successfully and unsuccessfully treated patients, endoscopy was performed if a patient reported symptoms suggesting ulcer recurrence.

RESULTS

The initial follow-up 13C-urea breath tests showed that all 23 patients remained free of infection at 12 to 19 months. Among 17 patients, the second test confirmed reinfection in 1 at 28 months. In two patients studied, the third test showed a negative result. The reinfection rate was 2.4% per patient year. Over the follow-up period, ulcer recurrence was found in 2 of 3 ulcer patients with eradication failure but in none of the 16 ulcer patients with successful eradication. The recurrence rate was significantly lower in successfully treated patients than in unsuccessfully treated patients (p < 0.05).

CONCLUSIONS

Reinfection with H. pylori is rare in children aged more than 5 years, and successful eradication significantly reduces ulcer recurrence. This study supports the benefit of eradication therapy in older children.

Helicobacter pylori risk associated with sibship size and family history of gastric diseases in Japanese adults

Helicobacter pylori is thought to be a cause of gastric cancer. Risk factors of H. pylori positivity were investigated among 4,361 public service workers in Japan. Sera and information on family history and lifestyle were collected, and H. pylori antibody was measured using the sera. Sex- and age-adjusted odds ratios of factors expected to influence H. pylori seropositivity were calculated. The factors with a significant influence were included in a logistic regression model and the final model was obtained by backward elimination. Sibship size (4 and more vs. 1), smoking habit (current vs. never), and paternal and siblings' histories of gastric diseases showed significant relationships to H. pylori seropositivity, with odds ratios (95% confidence intervals) of 1.5 (1.0-2.1), 0.8 (0.7-0.9), 1.5 (1.3-1.8) and 1.7 (1.1-2.6) respectively. However, spouse's history was not related. In the final model, sibship size and paternal history remained as positive factors, and smoking as a negative one. Contradictory results on the relationship between H. pylori status and smoking among recent studies indicate the existence of hidden confounding factors. It is suggested that infection from family members in childhood considerably affects the H. pylori status of Japanese adults, whereas infection between adults is rare.