AIM:

To revealed the prevalence of Helicobacter pylori (H. pylori) infection in the Bhutanese population.

METHODS:

We recruited a total of 372 volunteers (214 females and 158 males; mean age of 39.6 ± 14.9 years) from three Bhutanese cities (Thimphu, Punaka, and Wangdue). The status of H. pylori infection was determined based on five different tests: the rapid urease test (CLO test), culture, histology, immunohistochemistry (IHC), and serum anti H. pylori-antibody.

RESULTS:

The serological test showed a significantly higher positive rate compared with the CLO test, culture, histology and IHC (P < 0.001, P < 0.001, P = 0.01, and P = 0.01, respectively). When the subjects were considered to be H. pylori positive in the case of at least one test showing a positive result, the overall prevalence of H. pylori infection in Bhutan was 73.4%. The prevalence of H. pylori infection significantly decreased with age (P < 0.01). The prevalence of H. pylori infection was lower in Thimphu than in Punakha and Wangdue (P = 0.001 and 0.06, respectively). The prevalence of H. pylori infection was significantly higher in patients with peptic ulcers than in those with gastritis (91.4% vs 71.3%, P = 0.003).

CONCLUSION:

The high incidence of gastric cancer in Bhutan may be attributed to the high prevalence of H. pylori infection.

INTRODUCTION:

Screening tests for gastrointestinal diseases acceptable for population with a high sensitivity and high specificity can now be offered by clinical laboratories. This paper summarizes major recent advances in this area of laboratory medicine.

METHODS:

Relevant articles published within the last 5 years in the NLM (National Library of Medicine) PubMed - Medline database covering the three gastrointestinal diseases - colorectal cancer, coeliac disease, and atrophic gastritis were included for this overview.

RESULTS:

In Europe, colorectal cancer (CRCA) is the second most frequent malignant disease. Quantitative immunochemical analysis of the stool for haemoglobin provides the best screening test to date, with both sensitivity and specificity approaching 95%. Even though coeliac disease (CD) affects approximately 1% of the general population, it remains largely unrecognised. Recommended methods for screening currently involve the detection of IgA and IgG antibodies against tissue transglutaminase and deamidated gliadin peptide. Evaluations of screening are now discussed for other diseases of the gastrointestinal tract - such as chronic atrophic gastritis (CAG), and inflammatory bowel disease (IBD). Detection of infection by Helicobacter pylori and stomach-specific plasmatic biomarkers, especially pepsinogen I/II ratio, could help with the prevention of gastric carcinomas. The use of faecal calprotectin as a screening test could substantially reduce the number of invasive methods necessary for the diagnostic work-up of patients with IBD.

CONCLUSIONS:

Screening tests for CRCA and CD have been used worldwide for many years. Screening strategies for gastrointestinal diseases are suggested in the text, based on recent basic science, clinical papers as well as our own experience.

Helicobacter pylori antigen was prepared from an isolate from a patient with a duodenal ulcer. Serum samples were obtained from culture-positive H. pylori infected patients with duodenal ulcers, gastric ulcers and gastritis (n=30). As controls, three kinds of sera without detectable H. pylori IgG antibodies were used: 30 from healthy individuals without history of gastric disorders, 30 from patients who were seen in the endoscopy clinic but were H. pylori culture negative and 30 from people with other diseases. OFF-GEL electrophoresis, SDS-PAGE and Western blots of individual serum samples were used to identify protein bands with good sensitivity and specificity when probed with the above sera and HRP-conjugated anti-human IgG. Four H. pylori protein bands showed good (≥ 70%) sensitivity and high specificity (98-100%) towards anti-Helicobacter IgG antibody in culture- positive patients sera and control sera, respectively. The identities of the antigenic proteins were elucidated by mass spectrometry. The relative molecular weights and the identities of the proteins, based on MALDI TOF/ TOF, were as follows: CagI (25 kDa), urease G accessory protein (25 kDa), UreB (63 kDa) and proline/pyrroline- 5-carboxylate dehydrogenase (118 KDa). These identified proteins, singly and/or in combinations, may be useful for diagnosis of H. pylori infection in patients.

Streptocara spp. infections are reported to cause gastritis, proventriculitis, esophagitis, and pharyngitis in various waterfowls, especially diving ducks. In the present paper, we describe severe fatal diphtheritic pharyngitis and esophagitis caused by Streptocara incognita in three female mute swans (Cygnus olor) in Bosnia and Herzegovina. Prior to death, the swans were showing signs of lethargy, anorexia, and reluctance to move. At necropsy, in all swans severe diphtheritic pharyngitis and esophagitis with deep, dark red hemorrhagic ulcerations were observed. Numerous thin, white, up to 1-cm-long nematodes, identified as S. incognita, were observed embedded in the pharyngeal and esophageal mucosa under the diphtheritic membranes. Histopathology revealed severe fibrinonecrotic inflammation with numerous cross-sections of the parasites. To the authors' knowledge, this is the first report of severe, fatal streptocariasis in mute swans.

To investigate the predictive value of narrow-band imaging with magnifying endoscopy (NBI-ME) for identifying gastric intestinal metaplasia (GIM) in unselected patients.We prospectively evaluated consecutive patients undergoing upper endoscopy for various indications, such as epigastric discomfort/pain, anaemia, gastro-oesophageal reflux disease, suspicion of peptic ulcer disease, or chronic liver diseases. Patients underwent NBI-ME, which was performed by three blinded, experienced endoscopists. In addition, five biopsies (2 antrum, 1 angulus, and 2 corpus) were taken and examined by two pathologists unaware of the endoscopic findings to determine the presence or absence of GIM. The correlation between light blue crest (LBC) appearance and histology was measured. Moreover, we quantified the degree of LBC appearance as less than 20% (+), 20%-80% (++) and more than 80% (+++) of an image field, and the semiquantitative evaluation of LBC appearance was correlated with IM percentage from the histological findings.We enrolled 100 (58 F/42 M) patients who were mainly referred for gastro-esophageal reflux disease/dyspepsia (46%), cancer screening/anaemia (34%), chronic liver disease (9%), and suspected celiac disease (6%); the remaining patients were referred for other indications. The prevalence of Helicobacter pylori (H. pylori) infection detected from the biopsies was 31%, while 67% of the patients used proton pump inhibitors. LBCs were found in the antrum of 33 patients (33%); 20 of the cases were classified as LBC+, 9 as LBC++, and 4 as LBC+++. LBCs were found in the gastric body of 6 patients (6%), with 5 of them also having LBCs in the antrum. The correlation between the appearance of LBCs and histological GIM was good, with a sensitivity of 80% (95%CI: 67-92), a specificity of 96% (95%CI: 93-99), a positive predictive value of 84% (95%CI: 73-96), a negative predictive value of 95% (95%CI: 92-98), and an accuracy of 93% (95%CI: 90-97). The NBI-ME examination overlooked GIM in 8 cases, but the GIM was less than 5% in 7 of the cases. Moreover, in the 6 false positive cases, the histological examination showed the presence of reactive gastropathy (4 cases) or H. pylori active chronic gastritis (2 cases). The semiquantitative correlation between the rate of LBC appearance and the percentage of GIM was 79% (P < 0.01).NBI-ME achieved good sensitivity and specificity in recognising GIM in an unselected population. In routine clinical practice, this technique can reliably target gastric biopsies.

Residual mucosa in the gastric stump after pylorus-preserving gastrectomy (PPG) is considered a risk factor for the development of gastric stump carcinoma (GSC). Duodenogastric reflux (DGR) and Helicobacter pylori (H. pylori) infection are suspected to contribute to the development of GSC. The aim of this study was to investigate the prevalence of H. pylori in the residual stomach after PPG for gastric cancer and to assess factors associated with the presence of H. pylori. We investigated 72 patients who had undergone PPG at least 1 year prior to the study and were confirmed to be positive for H. pylori infection on presurgical endoscopic biopsy. The extent of DGR, the prevalence of H. pylori infection based on H. pylori stool antigen (HpSA) tests and the severity of gastritis were analyzed in these post-PPG patients. None of the patients had DGR, as shown by 99mTc-PMT. Of the 72 post-PPG patients, 33 (46%) were positive for HpSA. The prevalence of H. pylori infection was significantly lower after surgery than before surgery. The endoscopic severity of remnant gastritis, as well as histological inflammation and activity, were higher in H. pylori-positive patients than in H. pylori-negative patients. In conclusion, some patients who undergo PPG and are negative for DGR experience spontaneous clearance of H. pylori infection.

We report on three patients who developed four episodes of acute pancreatitis while their systemic lupus erythematosus was active and being treated with prednisolone. In all three, gastritis was first considered and treated due to abdominal pain, vomiting, and epigastric tenderness, but their symptoms did not improve. Then pancreatic enzymes were measured, which confirmed pancreatitis. Imaging studies showed an enlarged pancreas in one case, a normal pancreas in two cases, and a focal hypodense nonenhancing parenchyma in one case. Corticosteroids were prescribed for both active SLE and SLE-related pancreatitis. Pulse methylprednisolone was prescribed in one episode, increasing oral prednisolone in one episode, and the same dose of prednisolone continued in the other two episodes. All cases recovered without complications. SLE-related pancreatitis should be considered in SLE patients when the SLE is active and a patient develops abdominal pain and vomiting.

To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori) strains from Colombia on the host cell biology.Eighty-four H. pylori-cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n = 17), atrophic gastritis (n = 17), duodenal ulcer (n = 16), intestinal metaplasia (n = 16) and gastric cancer (n = 18), were included. To determine the integrity of the cag pathogenicity island (cagPAI) we evaluated the presence of cagA, cagT, cagE, and cag10 genes by polymerase chain reaction. AGS gastric epithelial cells were infected with each strain and assayed for translocation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of "hummingbird" cells (> 15 μm) was determined.Overall 72% (60/84) of the strains were found to harbor a functional cagPAI. Levels of phosphorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gastritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P < 0.02; 49.1% ± 23.1% vs 26.2% ± 14.8%, P < 0.045; 49.1% ± 23.1% vs 21.5% ± 19.5%, P < 0.043 and 49.1% ± 23.1% vs 29.5% ± 27.1%, P < 0.047 respectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGS cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL, P < 0.0001). We did not observe differences in the extent of cell elongation induction between strains with a functional or a defective cagPAI in 6 h cocultures. At 24 h post infection strains with functional cagPAI showed high diversity in the extent of hummingbird phenotype induction ranging from 7% to 34%. cagPAI defective strains induced significantly lower levels of elongation than strains with functional cagPAI with one or more than one EPIYA-C motif (15.1% ± 5.2% vs 18.9% ± 4.7%, P < 0.03; and 15.1% ± 5.2% vs 20.0% ± 5.1%, P < 0.003 respectively). No differences were observed in cellular elongation induction or IL-8 expression among H. pylori strains bearing one and more than one EPIYA-C motifs, neither at 6 h nor at 24 h of coculture. There were no associations between the levels of induction of cell elongation or IL-8 expression and number of EPIYA motifs or pathology.The present work describes a lack of association between H. pylori CagA protein EPIYA motifs variations from Colombian isolates and disease-associated cellular responses.

Infection with Helicobacter pylori leads to gastritis, peptic ulcers and gastric cancer. Moreover, when the gastric mucosa is exposed to H. pylori, gastric mucosal inflammatory cytokine interleukin-8 (Il-8) and reactive oxygen species increase. Anthocyanins have anti-oxidative, antibacterial and anti-inflammatory properties. However, the effect of anthocyanins in H. pylori-infected cells is not yet clear. In this study, therefore, the effect of anthocyanins on H. pylori-infected human gastric epithelial cells was examined. AGS cells were pretreated with anthocyanins for 24 hrs followed by H. pylori 26695 infection for up to 24 hrs. Cell viability and ROS production were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and 2',7'-dichlorofluorescein diacetate assay, respectively. Western blot analyses and RT-PCR were performed to assess gene and protein expression, respectively. IL-8 secretion in AGS cells was measured by ELISA. It was found that anthocyanins decrease H. pylori-induced ROS enhancement. Anthocyanins also inhibited phosphorylation of mitogen-activated protein kinases, translocation of nuclear factor-kappa B and Iκβα degradation. Furthermore anthocyanins inhibited H. pylori-induced inducible nitric oxide synthases and cyclooxygenase-2 mRNA expression and inhibited IL-8 production by 45.8%. Based on the above findings, anthocyanins might have an anti-inflammatory effect in H. pylori-infected gastric epithelial cells.

BACKGROUNDAIMS: This study evaluated the effect of Helicobacter pylori eradication on functional dyspepsia (FD), and the relationship between the changes of histological gastritis and FD symptom responses.A total of 213 FD patients diagnosed by Rome III criteria were consecutively enrolled. H. pylori tests and gastritis grade by the Sydney system were performed before and 1 year after the proton pump based-eradication therapy for 7 days. Serum levels of pepsinogen, and genetic polymorphisms IL-6, IL-8 and IL-10 were investigated.Total of 91 patients completed the 1 year follow-up. When the response rate of dyspepsia was compared at 1 year between the non-eradicated group (n = 24) and eradicated group (n = 67), each group showed complete response of 62.5% and 62.7%; satisfactory response (≥ 50%) of 0.0% and 19.4%; partial response (< 50%) of 12.5% and 11.9%; and refractory response of 25.0% and 6.0%, respectively (P = 0.015). In addition, the responder group (complete + satisfactory response) at 1 year showed improvement of activity and chronic inflammation in both the antrum and corpus (all P < 0.001). Multivariate analysis showed that H. pylori eradication (OR, 5.81; 95% CI, 1.07-31.59) and symptom improvement at 3 month (OR, 28.90; 95% CI, 5.29-157.82) were associated with the improvement of dyspepsia at 1 year. Among the successfully eradicated FD patients (n = 67), male (P = 0.013) and higher initial BMI (P = 0.016) were associated with the improvement of dyspepsia at 1 year.H. pylori eradication improved FD symptoms, as well as gastritis at 1 year, suggesting that inflammation mediates FD.