A Study of Association between H. Pylori Genotype and Chronic Gastritis

The prevalence of Helicobacter pylori (HP) infection is very high in Bangladesh. Chronic gastritis due to H. pylori is commonly associated with important gastric diseases such as peptic ulcer diseases or gastric carcinoma and MALT-oma. The natural course of chronic gastritis is HP-associated antral gastritis or pangastritis or rarely atrophies. This study was done to see the association of H. pylori genotypes with chronic gastritis. This observational cross sectional study was carried out at Bangabandhu Sheikh Mujib Medical University from July 2012 to April 2013 to find out the association of H. pylori genotypes with chronic gastritis in dyspeptic patients of Bangladesh. A total of 50 dyspeptic subjects were involved in the study whose upper GI endoscopies were carried out in presence of an experienced endoscopist. During the procedure four biopsies were taken, two from the antrum and two from body of the stomach. Endoscopic diagnosis was categorized into normal and erosive gastritis. Two (one from antrum and one from body) biopsy samples were collected in phosphate buffer saline and PCR analysis carried out by Multiplex PCR assay. Another two were collected in 10% formalin and histopathological examination was done according to updated Sydney system of classification. Among 50 patents only 34 were PCR positive. So, only 34 subjects were included in the study. Among them 21 patients (61.8%) were male and 13 patients (38.2%) were female, with the mean age of 29.91 years. Endoscopy revealed erosive gastritis in 5(14.7%) patients and normal findings in 29(86.3%) patients. Amongst the strains, cagA gene was detected in 58.8% and was not significantly associated with severity of any parameter of chronic gastritis such as H. pylori density, inflammation (mononuclear infiltration), activity (neutrophilic infiltration), atrophy and intestinal metaplasia. All the strains were positive for vacA allele. s1m1 (55.9%) genotype was most predominant. No vacA allele (s1m1, s1m2, s2m1 and s2m2) were significantly associated with severity of chronic gastritis. In this study, H. pylori genotype -cagA, vacA-s1, s2, m1, m2 allele and histological grading of chronic gastritis according to updated Sydney system of classification is identified. This study will identify the genotypes associated with severe gastritis in our country and thereby help us to take appropriate preventive measure. Further study with larger sample size may be carried out to establish proper association between different genotypes and parameters of chronic gastritis.