Helicobacter pylori and peptic ulcer disease.

Medical therapy for duodenal or gastric ulcer disease has traditionally involved gastric acid antisecretory therapy for 4 to 8 weeks to promote initial healing and indefinitely to prevent recurrences of ulcer. The discovery of Helicobacter pylori in most patients with peptic ulcer disease has led to a change in this approach. Therapy designed to eradicate H pylori may facilitate ulcer healing with acid antisecretory agents and, more important, may greatly reduce the incidence of ulcer recurrence, obviating the need for maintenance antisecretory therapy. Regimens designed to eradicate H pylori are difficult to comply with, however, and are associated with adverse effects in some patients. In this article we review the diagnosis and treatment of H pylori infection in patients with peptic ulcer disease and make recommendations regarding the use of conventional ulcer therapies and therapies designed to eradicate H pylori.     

Clinical and pathological importance of vacA allele heterogeneity and cagA status in peptic ulcer disease in patients from North Brazil

We have examined the prevalence of gene cagA and vacA alleles in 129 patients, 69 with gastritis and 60 with peptic ulcer diseases from North Brazil and their relation with histopathological data. vacA and cagA genotype were determined by polymerase chain reaction. Hematoxylin-eosin staining was used for histological diagnosis. 96.6% of the patients were colonized by Helicobacter pylori strains harboring single vacA genotype (nont-mixed infection). Among them, 11.8% had subtype s1a, 67.8% had subtype s1b, and 17% subtype s2. In regard to the middle region analysis, m1 alleles were found in 75.4% and m2 in 21.2% of patients. The cagA gene was detected in 78% patients infected with H. pylori and was associated with the s1-m1 vacA genotype. The H. pylori strains, vacA s1b m1/cagA-positive, were associated with increased risk of peptic ulcer disease and higher amounts of lymphocytic and neutrophilic infiltrates and the presence of intestinal metaplasia. These findings show that cagA and vacA genotyping may have clinical relevance in Brazil.     

Curing Helicobacter pylori infection in patients with duodenal ulcer does not provoke gastroesophageal reflux disease

Background. It has been suggested that the incidence of gastroesophageal reflux disease (GERD) increases after successful eradication of Helicobacter pylori infection. We present data on development of GERD from a controlled study of H. pylori eradication in 165 duodenal ulcer patients.
Methods. Patients (mean age, 55 years; 102 men; current smokers; n = 74) were randomly assigned 2 : 1 to receive omeprazole, 40 mg twice daily, in combination with either amoxicillin, 750 mg twice daily, or placebo. Endoscopy and dyspeptic symptoms, including heartburn, were assessed at inclusion and at 6, 12, and 24 months after treatment. In addition, symptoms were assessed at 18 months. Patients with erosive esophagitis or reflux symptoms requiring treatment at inclusion were not included in the study.
Results. Fifty-one of 145 (35%) evaluable patients developed heartburn, and 13 of 145 (9%) developed esophagitis during follow-up. The life-table analysis of the cumulated risk of developing heartburn showed that patients whose H. pylori infection was eradicated had a significantly lower risk for developing heartburn than those with persistent H. pylori infection. The groups did not show any difference in cumulative risk of developing esophagitis.
Conclusion. Our data show that successful eradication of H. pylori infection does not increase the incidence of GERD in duodenal ulcer patients.     

No correlation of babA2 with vacA and cagA genotypes of Helicobacter pylori and grading of gastritis from peptic ulcer disease patients in Brazil

BACKGROUND: The babA2 gene, which encodes a blood-group antigen-binding adhesin that mediates attachment of Helicobacter pylori to human Lewis(b) antigens on gastric epithelial cells, has been associated with a higher risk of peptic ulcer and gastric cancer. The purpose of this study was to ascertain the frequency of babA2 genotype in H. pylori strains of patients with peptic ulcer and to correlate with other virulence factors. MATERIALS AND METHODS: vacA, cagA, and babA2 genotypes of H. pylori were determined by using polymerase chain reaction (PCR). DNA was extracted from positive urease test gastric samples of 150 patients with peptic ulcer. Antrum and corpus biopsies were taken for histologic examination according to the updated Sydney system classification. RESULTS: babA2 genotype was present in 104 (69.3%) and cagA in 113 (75.3%) gastric samples. No significant correlation was observed between babA2 and vacAs1 genotype or between babA2 and cagA status. The correlation of vacAs1 genotype with positive cagA was statistically significant ( p < .001). The babA2-positive strain was more frequently found from the gastric samples of men, than of women (p = .01). Strains harboring cagA, vacAs1, and babA2 genotypes had no association to the grading of gastritis, presence of glandular atrophy, or intestinal metaplasia. The simultaneous presence of cagA, vacAs1, and babA2 was found in 32.6% of the H. pylori strains. CONCLUSIONS: babA2 genotype is frequently found in H. pylori strains from peptic ulcer disease in Brazil, although it has no significant correlation to the worsening of the gastritis and to other virulence markers such as vacAs1 and cagA.     

The cagA status of Helicobacter pylori isolates from dyspeptic children in Turkey

There are inconsistent reports regarding cytotoxin-associated gene A (cagA) status of Helicobacter pylori isolates and the severity of the mucosal lesions in children. The aim of this study was to determine the prevalence of cagA(+) strains and to evaluate its correlation with clinic and endoscopic findings. We examined 45 H. pylori strains that were grown on brain-heart infusion agar supplemented with 7% horse blood. Following 72 h of incubation colonies were harvested and bacterial DNA was extracted. Polymerase chain reaction primers F1 and B1 were used to amplify a 348-bp internal fragment of cagA. The prevalence of cagA in Turkish pediatric patients was 55.6%. No association was found between cagA status and the severity of gastro-duodenal lesions.     

Apoptosis in Helicobacter pylori gastritis is related to cagA status

BACKGROUND: Helicobacter pylori infection increases gastric epithelial cell apoptosis; however, the influence of cagA status is still controversial. We aimed to investigate if cagA status is related to apoptosis in H. pylori gastritis at different anatomic sites of the gastric mucosa. MATERIALS AND METHODS: We studied by immunohistochemistry (streptavidin-biotin method) pro-apoptotic (Bax and Bak) and antiapoptotic (Bcl-2 and Bcl-x) proteins expression, scored from 0 to 4, in gastric biopsies, at the antrum (lesser and greater curvatures), incisura, and corpus (greater curvature) from 50 patients with H. pylori gastritis (22 males, 28 females, median age 40 years) and eight non-infected patients (6 males, median age 39.6 years). H. pylori and cagA status were determined by polymerase chain reaction. RESULTS: Apoptotic proteins were expressed in a granular pattern, in the cytoplasm of foveolar cells; Bax and Bak expression was higher than Bcl-2 and Bcl-x in most cases and was significantly higher in patients infected by cagA-positive strains than in those infected by cagA-negative strains (p = .001). Bak expression was higher at the lesser curvature (antrum and incisura) than in the other regions (p = .002) and was correlated with atrophy. Anti-apoptotic proteins were significantly more expressed at the antral lesser curvature than in the other regions of the stomach (Bcl-2: p = .02; Bcl-x: p < .001). CONCLUSIONS: Infection with cagA-positive strains is significantly associated with overexpression of pro-apoptotic proteins in the gastric mucosa, mainly at the antral lesser curvature, which may have a role on atrophy development. Anti-apoptotic proteins were also overexpressed at the lesser curvature, which may occur to keep epithelial cell turnover or might be related to malignant transformation.     

Effect of Helicobacter pylori eradication on peptic ulcer disease complicated with outlet obstruction

Background. At present, the prevalence of Helicobacter pylori ( H. pylori ) in complicated peptic ulcer and the effect of H. pylori eradication on complicated peptic ulcer have not been fully established. In this study, we report the prevalence of H. pylori in peptic ulcer patients complicated with gastric outlet obstruction, effectiveness of oral eradication therapy on these patients, and their long-term follow up.
Patients and Methods. Ten consecutive patients presenting with clinically and endoscopically significant obstructed peptic ulcers were included in this study. During each endoscopy, seven gastric biopsy specimens were obtained and analyzed for H. pylori colonization.
Results. The antral mucosal biopsy specimens were positive for H. pylori in nine patients. H. pylori infection was eradicated and complete ulcer healing was observed in all patients. The mean follow-up period was 14 (7–24) months. One patient had duodenal perforation and underwent surgical intervention following medical treatment, despite the eradication of H. pylori. Ulcer recurrence was noted in two (22.2%) of nine patients, and in one of them the recurrent ulcer was complicated with obstruction (11.1%). The mean time to ulcer recurrence was 17 months (range, 10–24 months). The biopsies and CLOtests were H. pylori negative at the time of ulcer or erosion recurrence in two patients.
Conclusion. We suggest that H. pylori eradication may improve the resolution in obstructive ulcer cases with colonization.     

Social status does not predict corticosteroid levels in postdispersal male spotted hyenas

In social species with low rates of direct male competition levels of corticosteroids should not correlate with social status. Male spotted hyenas acquire social status by observing strict queuing conventions over many years, and thus levels of male-male aggression are low, and male social status and tenure are closely correlated. In this study, we investigated whether the low rate of direct male competition in spotted hyenas was reflected in fecal corticosteroid levels of adult males in the Serengeti National Park. Also, interactions with dominant females may influence corticosteroid levels of males, and it has been suggested recently that males with a long tenure (high rank) are more stressed by females than males with a short tenure (low rank). We tested whether there is a difference in the likelihood of being aggressively challenged by dominant females between long-tenured and short-tenured males. Short-tenured males were more likely to elicit an aggressive response by females than long-tenured males, but previous work suggests that they also interacted less frequently with females, thus avoiding putting themselves in a potentially stressful situation. Thus, as expected, the comparison of males in three different clans revealed no correlation between social status or tenure and fecal corticosteroid levels. However, males of the largest clan had the highest levels of fecal corticosteroids, possibly reflecting higher rates of social interactions in larger clans.     

Prostaglandin E in peptic ulcer disease

Prostaglandin E₁ and E₂ inhibit gastric secretion in vivo and in vitro under a variety of conditions. It is not known whether these compounds may play a role in normal gastric secretory physiology or in the pathophysiology of peptic ulcer disease. Six normal adults and six patients with documented duodenal ulcer disease were studied under basal conditions and during gastric secretory stimulation with betazole. Prostaglandin E in plasma and gastric juice was measured by radioimmunoassay. Prostaglandin E was significantly higher in the plasma of normal volunteers both in the basal state and during stimulation. Gastric juice prostaglandin E was also significantly higher in normal volunteers during the basal state but the difference disappeared during stimulation. The relative deficiency of prostaglandin E in the ulcer group may indicate a role for prostaglandins in the pathophysiology of gastric hypersecretion.     

Mixed infection with cagA positive and cagA negative strains of Helicobacter pylori lowers disease burden in The Gambia

Background

The prevalence of Helicobacter pylori including strains with putatively virulent genotypes is high, whereas the H. pylori-associated disease burden is low, in Africa compared to developed countries. In this study, we investigated the prevalence of virulence-related H. pylori genotypes and their association with gastroduodenal diseases in The Gambia.

Methods and Findings

DNA extracted from biopsies and H. pylori cultures from 169 subjects with abdominal pain, dyspepsia or other gastroduodenal diseases were tested by PCR for H. pylori. The H. pylori positive samples were further tested for the cagA oncogene and vacA toxin gene.One hundred and twenty one subjects (71.6%) were H. pylori positive. The cagA gene and more toxigenic s1 and m1 alleles of the vacA gene were found in 61.2%, 76.9% and 45.5% respectively of Gambian patients harbouring H. pylori. There was a high prevalence of cagA positive strains in patients with overt gastric diseases than those with non-ulcerative dyspepsia (NUD) (p = 0.05); however, mixed infection by cagA positive and cagA negative strains was more common in patients with NUD compared to patients with gastric disease (24.5% versus 0%; p = 0.002).

Conclusion

This study shows that the prevalence of H. pylori is high in dyspeptic patients in The Gambia and that many strains are of the putatively more virulent cagA⁺, vacAs1 and vacAm1 genotypes. This study has also shown significantly lower disease burden in Gambians infected with a mixture of cag-positive and cag-negative strains, relative to those containing only cag-positive or only cag-negative strains, which suggests that harbouring both cag-positive and cag-negative strains is protective.     

幽门螺杆菌cagA克隆表达

克隆表达4株幽门螺杆菌的cagA基因,以方便地获得大鼠CagA蛋白和重组表达质粒,为临床诊断CagA阳性幽门螺杆菌感染,以及进一步研究不同类型CagA功能及其与疾病关系提供材料。PCR扩增幽门螺杆菌的cagA基因,克隆至PinPoint^TMXa-1T载体,酶切鉴定连接方向,IPTG诱导正向连接克隆表达CagA融合蛋白并进行SDS－PAGE和Western blots鉴定。结果显示PCR扩增得到3.5-3.8kb的CagA基因,PCR及酶切鉴定得到正向连接的重组克隆,SDS－PAGE及Western blots证实正向连接的重组克隆表达CagA融合蛋白。构建了4种cagA的重组表达质粒,通过转化同一宿主菌可研究不同CagA的功能和致病性差异;通过亲和层析纯化融合蛋白可获大量CagA蛋白,用于血清学诊断CagA阳性幽门螺杆菌感染,及不同抗原性CagA与疾病之间的关系。     

Eradication of Helicobacter pylori for the prevention of peptic ulcer rebleeding

AIM: To evaluate the effect of Helicobacter pylori eradication on ulcer bleeding recurrence in a prospective, long-term study including more than 400 patients. METHODS: Patients with peptic ulcer bleeding were prospectively included. H. pylori infection was confirmed by rapid urease test, histology or (13)C-urea breath test. Several eradication regimens were used. Ranitidine 150 mg was administered daily until eradication was confirmed by breath test 8 weeks after completing eradication therapy. Patients with therapy failure received a second or third course of therapy. Patients with eradication success did not receive maintenance anti-ulcer therapy, and were controlled yearly with a repeated breath test. RESULTS: Four hundred and twenty-two patients were followed up for at least 12 months, with a total of 906 patient-years of follow up. Mean age was 59 years, and 35% were previous nonsteroidal anti-inflammatory drug (NSAID) users. Sixty-nine percent had duodenal, 24% gastric, and 7% pyloric ulcer. Recurrence of bleeding was demonstrated in two patients at 1 year (incidence: 0.22% per patient-year of follow up), which occurred after NSAID use in both cases. CONCLUSION: Peptic ulcer rebleeding does not occur in patients with complicated ulcers after H. pylori eradication. Maintenance anti-ulcer (antisecretory) therapy is not necessary if eradication is achieved.     

The prevalence of peptic ulcer not related to Helicobacter pylori or non-steroidal anti-inflammatory drug use is negligible in southern Europe

BACKGROUND AND AIM: Helicobacter pylori is the major cause of peptic ulcer disease, but the proportion of H. pylori-negative peptic ulcers seems to be increasing in developed countries. We investigated the frequency of H. pylori-negative peptic ulcer without intake of nonsteroidal anti-inflammatory drugs (NSAIDs) in a Mediterranean European country. MATERIALS AND METHODS: We prospectively collected consecutive patients with an endoscopically verified active peptic ulcer over 6 months from different areas of Spain. Helicobacter pylori infection was assessed by rapid urease test and histologic examination (corpus and antral biopsies). A (13)C-urea breath test was performed if H. pylori was not detected with the invasive test. Patients were considered H. pylori-negative if all three tests were negative. NSAID use was determined by structured data collection. RESULTS: Of 754 consecutive peptic ulcer patients, 16 (2.1%) were H. pylori-negative and had not used NSAIDs before the diagnosis. Of the 472 patients who had duodenal ulcers, 95.7% (n = 452) were H. pylori-positive and only 1.69% (n = 8) were negative for both H. pylori infection and NSAID use; 193 patients had benign gastric ulcers and 87% (n = 168) of them were infected by H. pylori (p <.001 vs. duodenal ulcers). NSAID intake was more frequent in gastric ulcer patients (52.8%) than in duodenal ulcer patients (25.4%; p <.001). Consequently, the frequency of H. pylori-negative gastric ulcer in patients not using NSAID was 4.1% (n = 8). CONCLUSION: Peptic ulcer disease is still highly associated with H. pylori infection in southern Europe, and only 1.6% of all duodenal ulcers and 4.1% of all gastric ulcers were not associated with either H. pylori infection or NSAID use.