Multivariate analysis of risk factors for development of duodenal ulcer in Helicobacter pylori-infected patients

Time trends in epidemiology of peptic ulcer disease in India over two decades

BACKGROUND

Epidemiology of peptic ulcer disease (PUD) in India differs from that in the West. It may have undergone a change with recent improvement in hygiene and availability of potent antisecretory and ulcerogenic drugs. We therefore tried to assess time-trends in the frequency of PUD over the past two decades.

METHODS

Records of patients with uninvestigated dyspepsia and no alarm symptoms who had undergone upper gastrointestinal endoscopy at our institution during the years 1988 (n = 2,358), 1992 (n = 2,240), 1996 (n = 5,261), 2000 (n = 7,051), 2004 (n = 5,767) and 2008 (n = 7,539) were retrospectively reviewed. The frequencies of duodenal and gastric ulcer disease in these groups were compared.

RESULTS

Of the 30,216 patients (age:41.7±12.7 years, 34 % females) during the six study periods, 2,360 (7.8 %) had PUD. The frequencies of both duodenal ulcer and gastric ulcer showed a decline from 1988 to 2008, i.e. from 12 % to 2.9 % and 4.5 % to 2.7 %, respectively (p-value <0.001 for trend for each). The decline was more marked for duodenal ulcer, and the ratio of duodenal to gastric ulcer declined from 2.7 in 1988 to 1.1 in 2008.

CONCLUSIONS

The epidemiology of PUD in India may have changed in the past two decades with the incidence of duodenal ulcer declining more rapidly than that of gastric ulcer.

In situ expression of cagA and risk of gastroduodenal disease in Helicobacter pylori-infected children

BACKGROUND AND AIM

Gastroduodenal disease is more common among adults and children with cagA+ Helicobacter pylori infection, but disease severity varies among those infected with cagA+ strains. We examined whether cagA in situ expression can predict disease manifestations among H pylori-infected children.

PATIENTS AND METHODS

Fifty-one children were selected from 805 patients with abdominal symptoms who underwent esophagogastroduodenoscopy with gastric biopsies. Endoscopic and histologic gastritis were scored and H pylori colonization was quantified by Genta stain and in situ hybridization expression of 16S rRNA and cagA.

RESULTS

Endoscopy was either normal (n = 14) or demonstrated nodularity (n = 18), gastric ulcer (n = 8) or duodenal ulcer (n = 11). H pylori was present in 7, 18, 6, and 10 children, respectively. Expression of 16S rRNA and cagA were significantly higher in children with ulcer compared with normal children. The fraction of H pylori bacteria expressing cagA in situ was higher in children with ulcer compared to those with endoscopic nodularity (P < 0.05).

CONCLUSIONS

Thus, cagA in situ expression is increased in H pylori-infected children with peptic ulcers and may play a role in the pathogenesis of peptic ulcer disease during childhood. Determination of in situ expression of cagA complements traditional isolation and in vitro testing of single-colony isolates.

Tobacco use increases susceptibility to bacterial infection

Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.

The association between the interleukin-1 polymorphisms and gastric cancer risk depends on the family history of gastric carcinoma in the study population

OBJECTIVES

The association between interleukin-1 polymorphisms, H. pylori and increased gastric cancer risk remains controversial.

AIMS

To compare the prevalence of these polymorphisms in individuals with two mutually exclusive diseases connected with infection, gastric cancer, and duodenal ulcer.

METHODS

121 gastric cancer and 119 duodenal ulcer patients. Genomic DNA was typed for polymorphisms at position -511, -31 in the interleukin-1beta gene (IL-1 beta) using primer extension and mass-spectrometry. Analysis of the variable number of tandem repeats in intron 2, in its receptor antagonist gene (IL-1RN) was performed by PCR and agarose gel electrophoresis.

RESULTS

All subjects were successfully genotyped for the three gene loci. IL-1 beta-511 was found to be in reverse linkage disequilibrium with IL-1 beta-31. The differences between gastric cancer and duodenal ulcer patients concerned only heterozygous variant of IL-1beta and were related to family history of gastric cancer, tumor stage, histology, site. Thus, CT carriers were found to have a higher risk of sporadic [OR 2.21 (95% CI, 1.22-3.99)], early [OR 2.81 (95% CI, 1.14-6.93)], diffuse [OR 2.48, (95% CI 1.21-5.09)] or non-cardia gastric cancer [OR 1.88 (95% CI 1.06-3.33)]. Furthermore, CT genotype was significantly more prevalent in gastric cancer patients with negative than in those with a positive family history (p = 0.039).

CONCLUSIONS

The association between the interleukin-1 polymorphisms and gastric cancer risk depends on the family history of gastric carcinoma in the study population. This phenomenon may be in part responsible for differences in results of interleukin-1 studies performed on populations with low and high gastric cancer prevalence.

[Helicobacter pylori identification by brush gastric cytology: a comparison with histologic method]

The purpose of this study was to verify the efficacy of brush gastric cytology for diagnosis of Helicobacter pylori infection in patients, submitted to elective gastroscopy, compared to the method of endoscopic histology. Endoscopy was performed on 157 patients, divided into two dyspeptic groups: group A (n = 27) with duodenal ulcer; and group B (n = 130) without ulcer. In group A, the percentage of positive cases detected by brush cytology (77.8%) was similar to histology (74.1%; p = 0.3). While in group B, brush cytology (71.5%) was superior to histology (63.1%; p = 0.00002). Brush cytology is a simple and useful diagnostic method. It was efficient for identification of Helicobacter pylori infection in both groups.

Seroprevalence of Helicobacter pylori among children in Sana'a, Yemen

BACKGROUND

Helicobacter pylori infection is primarily acquired in early childhood. Its transmission routes are debated. The aims of this study were to determine the seroprevalence of anti-H. pylori immunoglobulin G (IgG) in Yemeni children under 10 years of age, the potential risk factors for contracting H. pylori infection and co-infection of H. pylori with intestinal parasites.

METHODS

Enzyme-labeled immunosorbent assay was used to determine the H. pylori prevalence rate among 572 healthy volunteers aged less than 10 years. Formalin ether concentration methods were used to test the prevalence of intestinal parasites (intestinal roundworms and tapeworms). In addition, we interviewed participants regarding potential risk factors for contracting H. pylori infection.

RESULTS

The seroprevalence of H. pylori antibodies was 9%. The prevalence according to age varied from 0% in children under 2 years to 12.5% in age group 9-10 years. There was a correlation between the amounts of positive antibodies and increasing age. The prevalence rate of H. pylori antibodies was also significantly associated with the practice of drinking water from reused plastic jerry cans, with poor mouth hygiene and with co-infection by intestinal parasites.

CONCLUSION

The prevalence of H. pylori antibodies in Yemen among children under 10 years of age is higher than that reported from other regions for the same age groups. Yemen shares some but not all potential risk factors for H. pylori infection with countries in which similar socioeconomic conditions are found. A possible way of eliminating H. pylori from the population would be via public health measures, i.e. preventing the reuse of plastic jerry cans, and improving sanitation and the standard of living.

Helicobacter pylori infection: anything new should we know?

Over the past year, 2003-4, there have been a number of studies consolidating previous work in relation to pathogenesis of disease, diagnosis and management of Helicobacter pylori. Studies into the pathogenesis of disease have identified the main adhesin of H. pylori as an important virulence marker and as a potential target for therapy. Molecular investigations of both the strain and host variations have identified the action of several of the virulence factors, e.g. cagA, vacA, on disrupting host cell signalling and the consequences in respect of the release of chemokines from the damaged gastric epithelium and the effect on apoptosis. Over the past year, there have been further diagnostic kits developed based on modifications of current technology. Two promising areas of research for diagnosis are the use of host/strain genome polymorphisms as a means of identifying high-risk patients who may develop severe disease and the use of proteomics to identify potential antigens of diagnostic (or therapeutic) use. The three main antibiotics that are used in first-line eradication regimens are clarithromycin, metronidazole and amoxycillin. Of these, metronidazole has the highest prevalence of resistance, followed by clarithromycin; amoxycillin resistance is only rarely reported. The decreasing success of current first-line therapy is the driving force for the development of new antibiotic combinations and a search for novel sources for chemotherapeutic agents and novel therapeutic targets.