Genotyping of Helicobacter pylori strains from gastric biopsies by multiplex polymerase chain reaction. How advantageous is it?

Recent application of multiplex polymerase chain reaction (PCR) for genotyping Helicobacter pylori direct from biopsies revealed variable results (detection of amplicons from DNA extracted by boiling biopsies, variable size amplicons and deletions, uniform intensity of amplicon bands). We aimed to look at how applicable the technique is for determining cagA and vacA genotypes and to correlate the results with the severity of the disease. H. pylori strains from 52 patients (35 duodenal ulcers [DUs], 7 gastric ulcers [GUs], 10 gastritis) were included. Three antral biopsies were obtained for Campylobacter-like organism (CLO) and PCR. Primers for cagA, vacA s1s2, and m1m2 alleles were used. No PCR amplicons were detected from boiling biopsies; thus, DNA was extracted by QIAamp kit. H. pylori was positive in 84.6% of the patients (85.7% DU, 100% GU, and 70% gastritis). The cagA gene was detected in 86.6% DU, 71.4% GU, and 57.0% gastritis patients. The vacA allelic distribution among cagA-positive strains was 80.7% s1m1 in DU and 60.0% in GU patients, whereas 75.0% of gastritis had s1m2. No variability in the amplicon sizes was found, and the intensity of the amplicon bands was not uniform. A deleted band of approximately 420 bp below the m1 band was detected in strains from 2 DU and 1 GU patients. Although the multiplex PCR is a rapid and an effective tool for detecting several genes in a single-step system, one has to adjust for optimization of the technique when genotyping H. pylori direct from biopsies. A significant association was found between the cagA-positive vacA-s1m1 genotype and peptic ulcers.

H pylori infection and other risk factors associated with peptic ulcers in Turkish patients: a retrospective study.

AIM: To identify and evaluate the relative impact of H pylori infection and other risk factors on the occurrence of gastric ulcer (GU), duodenal ulcer (DU) and gastritis in Turkish patients. METHODS: A total of 4471 patients (48.3% female) out of 4863 attended the Samatya hospital in Istanbul (June 1999-October 2003) were included. The records of H pylori status (CLO-test), endoscopic findings of GU, DU and gastritis, personal habits (smoking, alcohol intake) and medication [non-steroidal anti-inflammatory drugs (NSAIDs), aspirin intake] were analyzed using multi-way frequency analysis. RESULTS: We have found that GU in the presence of H pylori had significant association with aspirin (P=0.0001), alcohol (P=0.0090) and NSAIDs (P=0.0372). DU on the other hand had significant association with aspirin/smoking/NSAIDs (P=0.0259), aspirin/alcohol (P=0.0002) and aspirin/smoking (P=0.0233), also in the presence of H pylori. In the absence of H pylori GU had significant association with alcohol/NSAIDs (P=0.0431), and NSAIDs (P=0.0436). While DU in the absence of H pylori had significant association with smoking/alcohol/ NSAIDs (P=0.0013), aspirin/NSAIDs (P=0.0334), aspirin/alcohol (P=0.0360). CONCLUSION: In the presence of H pylori, aspirin, alcohol and NSAIDs intake act as an independent risk factors that had an augmenting impact on the occurrence of GU and only together on the occurrence of DU in Turkish patients.

Helicobacter pylori anti-CagA antibodies: prevalence in symptomatic and asymptomatic subjects in Turkey.

BACKGROUND: Several reports have shown the prevalence of anti-CagA antibodies to be associated with the development of peptic ulcer diseases, while others have indicated that there is no such association. AIM: To examine the prevalence of antibodies to CagA and other Helicobacter pylori antigens in symptomatic and asymptomatic subjects in Turkey. subjects and METHODS: Sixty-six symptomatic subjects, 16 to 74 years of age, were examined for H pylori by biopsy-based tests and ELISA. One hundred nineteen asymptomatic subjects, 20 to 65 years of age, were also tested serologically for the presence of H pylori. Samples from both groups that were found to be positive for H pylori by ELISA were then tested by immunoblotting. RESULTS: Fifty-four (82%) symptomatic subjects and 76 (64%) asymptomatic subjects were found to be H pylori-positive by ELISA. Samples from 30 symptomatic subjects who were found to be H pylori-positive by ELISA were analyzed by immunoblotting. Antibodies to CagA (116 kDa) antigen were detected in immunoblots of 11 of 14 (79%) with chronic gastritis, 12 of 13 (92%) with duodenal ulcer and three of three (100%) with gastric cancer. Antigens of the following molecular weights were also detected in these 30 subjects: 89 kDa (VacA) in 21 (70%), 37 kDa in 21 (70%), 35 kDa in 19 (63%), 30 kDa in 27 (90%) and 19.5 kDa in 19 (63%). Immunoblots of 40 ELISA-positive asymptomatic subjects showed that 33 (83%) had antibodies to CagA antigen, 26 (65%) to VacA antigen, 30 (75%) to a 37 kDa antigen, 30 (75%) to a 35 kDa antigen, 39 (98%) to a 30 kDa antigen and 36 (90%) to a 19.5 kDa antigen. CONCLUSIONS: Antibodies to CagA antigen were prevalent in both groups, regardless of the presence of gastroduodenal disease.

Diffuse and psammomatous calcification in intestinal type gastric carcinoma: report of two cases with literature review.

Psammoma bodies are round, concentrically laminated calcospherites ranging from 5 to 100 µm in diameter. They may indicate certain types of tumors including papillary carcinoma of the thyroid, meningioma and papillary serous tumors of the ovary, and to a lesser extent may be found in leiomyomas and angiomas of the gastrointestinal tract. Dystrophic calcification is uncommon in gastric cancer and displays either diffuse or psammomatous pattern. Diffuse type calcification is generally seen within the pools of mucin in advanced mucinous adenocarcinoma. Conversely, psammomatous calcification is associated with non-mucinproducing carcinomas and detected not only within the carcinomatous glandular lumina but also in the stroma. Total gastrectomy specimens of a 74-year-old male and a 54-year-old female with moderately differentiated intestinal type adenocarcinomas revealed diffuse and psammomatous calcification, respectively. Although diffuse type calcification is well-documented, to date it has not been reported in non-mucin-producing intestinal gastric carcinoma. Moreover, the psammomatous type is exceptionally rare, and only six such cases have been reported in the literature; the current patient represents the seventh case.

Canonical correlation analysis of factors involved in the occurrence of peptic ulcers.

The impact of risk factors on the development of peptic ulcers has been shown to vary among different populations. We sought to establish a correlation between these factors and their involvement in the occurrence of peptic ulcers for which a canonical correlation analysis was applied. We included 7,014 patient records (48.6% women, 18.4% duodenal ulcer [DU], 4.6% gastric ulcer [GU]) of those underwent upper gastroendoscopy for the last 5 years. The variables measured are endoscopic findings (DU, GU, antral gastritis, erosive gastritis, pangastritis, pyloric deformity, bulbar deformity, bleeding, atrophy, Barret esophagus and gastric polyp) and risk factors (age, gender, Helicobacter pylori infection, smoking, alcohol, and nonsteroidal anti-inflammatory drugs [NSAIDs] and aspirin intake). We found that DU had significant positive correlation with bulbar deformity (P=2.6 x 10(-23)), pyloric deformity (P=2.6 x 10(-23)), gender (P=2.6 x 10(-23)), H. pylori (P=1.4 x 10(-15)), bleeding (P=6.9 x 10(-15)), smoking (P=1.4 x 10(-7)), aspirin use (P=1.1 x 10(-4)), alcohol intake (P=7.7 x 10(-4)), and NSAIDs (P=.01). GU had a significantly positive correlation with pyloric deformity (P=1,6 x 10(-15)), age (P=2.6 x 10(-14)), bleeding (P=3.7 x 10(-8)), gender (P=1.3 x 10(-7)), aspirin use (P=1.1 x 10(-6)), bulbar deformity (P=7.4 x 10(-4)), alcohol intake (P=.03), smoking (P=.04), and Barret esophagus (P=.03). The level of significance was much higher in some variables with DU than with GU and the correlations with GU in spite of being highly significant the majority, were small in magnitude. In conclusion, Turkish patients with the following endoscopic findings bulbar deformity and pyloric deformity are high-risk patients for peptic ulcers with the risk of the occurrence of DU being higher than that of GU. Factors such as H. pylori, smoking, alcohol use, and NSAIDs use (listed in a decreasing manner) are risk factors that have significant impact on the occurrence of DU; aspirin has a significant impact on both DU and GU.

Endoscopic diagnoses and CLO test results in 9239 cases, prevalence of Helicobacter pylori in Istanbul, Turkey.

BACKGROUND: Helicobacter pylori is implicated in the etiology of gastric and duodenal ulcer, non-ulcer dispepsia, atrophic gastritis, gastric adenocarcinoma and lymphoma. METHODS: Between November 1995 and December 2004, the presence of H. pylori was investigated using the CLO test in 9239 patients who underwent upper gastrointestinal endoscopy at a single institution in Istanbul, Turkey. The results were evaluated as early-late positive, and negative. RESULTS: There were 4667 women (50.51%) with a mean age of 44.5 years (range, 13-90 years), and 4572 men (49.49%) with a mean age of 45.7 years (range, 11-85 years). The CLO test was positive in 41.44% of cases. The most frequent symptoms on admission were epigastric pain (46.2%) and burning (19.6%). The most frequent endoscopic diagnosis was pangastritis (64%) and non-erosive duodenitis (30.5%). The H. pylori positivity was 61.53% during the first 5-year period and 38.47% during the second 5-year period. The H. pylori positivity was significant in patients using non-steroidal anti-inflamatory drugs and tobacco (P < 0.001). DISCUSSION AND CONCLUSION: Helicbacter pylori prevelance remains an important health problem for Turkey although it has diminished in parallel to the national development during the last years. Helicbacter pylori, as a first-degree carcinogen, should be investigated and eradicated particularly in high-risk patients.

A follow-up study on the effect of Helicobacter pylori eradication on the severity of gastric histology.

Helicobacter pylori genetic diversity and geographic distribution affect the severity of gastric histology; while eradication heals gastritis, the improvement of atrophy and intestinal metaplasia (IM) is still controversial. We investigated whether H. pylori infection and genotypes (cagA-vacA) influence the histological changes and whether eradication resolves these changes. Twenty-one patients (11 duodenal ulcer, 2 gastric ulcer, 8 gastritis) received treatment. Biopsies for CLO, PCR, histology, and culture were collected before and at 1 and 12 months after treatment, and serum samples at 0, 1, 2, 6, and 12 months. H. pylori eradication was achieved in 71% of the patients. Histological scores for H. pylori densities were significantly higher in the antrum and incisura angularis. Scores for mononuclear cell and neutrophil infiltration were significantly higher in regions with a high H. pylori density and improved progressively after eradication. Eight patients with atrophy including five with IM showed no significant changes 12 months after eradication. The cagA gene, detected in 13 (62%), the vacA-sla gene, in 20 (95%), and the vacA-m1 gene, in 12 (57%) of 21 patients were significantly associated with duodenal ulcer. A gradual decline in antibody titer reached an average of 67% 12 months after eradication. H. pylori infection and the associated genotypes (cagA of Western type) affect the severity of the gastric histology (mild forms of atrophy and IM) and the disease outcome. Eradication of H. pylori resulted in healing of gastritis, but with no significant improvement in atrophy or IM.

Analysis of Helicobacter pylori genotypes and correlation with clinical outcome in Turkey.

The predominant Helicobacter pylori strains circulating among geographic locations differ in regard to genomic structure. The association of the cagA-positive, vacA s1 genotypes with peptic ulcer disease (PUD) and gastric cancer was reported in Western countries but not in East Asian countries. Strains from Western countries predominantly possessed cagA type 2a, vacA s1a or s1b/m1a, or vacA m2a genotypes, whereas strains from East Asia possessed cagA type 1a, vacA s1c/m1b, or vacA m2b genotypes. Whether the Turkish strains possessed such genotypes was investigated and correlated with the disease outcome. Seventy-three patients from Turkey were enrolled. H. pylori was detected in 65 (89%) patients (22 with gastritis, 33 with PUD, and 10 with gastric cancer) by any of the following tests: Campylobacter-like organism test, culture, or PCR. Among the H. pylori-positive patients, presence of the cagA gene (78%) was significantly associated with PUD (P < 0.00001), gastric cancer (P < 0.001), and vacA s1a genotypes (P < 0.0001). Multiple vacA genotypes were more prevalent in PUD and gastric cancer patients than in patients with gastritis. Restriction fragment length polymorphism analysis of the cagA gene revealed three different patterns with no significant association with clinical outcome. Turkish strains examined predominantly possessed cagA type 2a, vacA s1a/m1a, or vacA m2a genotypes, which were typical genotypes in strains from Western countries. This fact might be one of the reasons for the low prevalence of severe gastroduodenal diseases in Turkey compared to the East Asian countries.

Therapeutic vaccination in chronic hepatitis B.

AIMS: The aim was to test the efficacy of a pre-S2-containing vaccine (Genhevac-B) in chronic hepatitis B (CHB). Twenty-five naive patients (22 male, three female; median age 35; range: 6-69 years) with CHB were recruited. The inclusion criteria were: hepatitis B e antigen (HBeAg) positive or HBV-DNA detectable with liquid hybridization; alanine aminotransferase (ALT) is at least 1.5-fold the upper normal limit and histological evidence of chronic hepatitis. METHODS: In the first period, all patients received monthly injections of 20, 40 and 60 microg of the vaccine. One month after the last injection, patients who still had HBV-DNA were divided into two randomly assigned groups. While the patients in the first group and the patients who lost HBV-DNA in the first period continued to receive monthly injections of 20 microg vaccine for a further 6 months, the patients in the second group received 9 MU interferon alpha-2b (Roferon-A), three times per week using the same method as for the first group. Patients were followed up after 12 months without treatment. Response was defined as the loss of HBV-DNA and normalization of ALT. RESULTS: Six of the 25 patients lost HBV-DNA after 3 months. Nine of the remainder were randomly placed in the first group (vaccine-only) and 10 were placed in the second group (vaccine + interferon). End-of-treatment response was achieved, overall, 8/15 from the vaccine group and 6/10 from the combination. One patient from each group relapsed during the follow up. Overall, the sustained response (SR) rate was 46% (7/15) in the vaccine group, and 50% (5/10) in the combination group. Histological improvement was achieved in 6/7 SR with vaccine-only and all five with combination treatment, while 1/8 of failures of vaccine and 2/5 of failures of combination improved. CONCLUSIONS: It was concluded that Genhevac-B decreases serum HBV-DNA levels in the majority of patients with CHB and sustained clearance was achieved in some patients. Combination of interferon-alpha with Genhevac-B is effective for the vaccine failures and may increase sustained response compared to interferon-alpha alone. However, the mechanism of action is yet to be explained.