Virulence attributes of Helicobacter pylori isolates & their association with gastroduodenal disease.

Background & objectives Certain genotype(s) of Helicobacter pylori strains may play important role in the development of gastric cancer (GC) and peptic ulcer disease (PUD). This study was undertaken to investigate the association of cagA, cagA3/ region subtypes, babA2 and vacA genotypes of H. pylori with GC, PUD and non-ulcer dyspepsia (NUD) as there are no such studies from India. Methods A total of 348 consecutive adult patients (NUD 241, PUD 45, GC 62) undergoing upper gastrointestinal endoscopy between September 2002 and May 2007 in a tertiary referral centre at Lucknow, north India, were enrolled. H. pylori infection was diagnosed by rapid urease test, culture, histopathology and PCR. Genotyping for cagA, cagA3/ subtypes, babA2 and vacA was performed by PCR using sequence specific primers. Results H. pylori infection was higher in patients with PUD than with GC (80 vs. 56.5%, P < 0.01) and NUD (80 vs. 55.2%, P= 0.002). cagA positive H. pylori isolates were detected in 80 per cent in GC, 83.3 per cent in PUD and 76.7 per cent in NUD with no significant difference among them. Only A subtype of cagA3/ was detected and its distribution in GC, PUD and NUD was 68.8, 69.4 and 52.6 per cent respectively. Presence of babA2 genotype was 31.4 per cent and it had significant association with PUD when compared with NUD (52.8 vs. 26.3%, P<0.003). On univariate regression analysis, s1a allele was associated with GC (P<0.050) and s1a/m2 vacA genotype with both GC (P=0.014) and PUD (P=0.016). Interpretation & conclusions H. pylori infection was strongly associated with PUD with a very high proportion of patients with GC have s1a allele and s1a/m2 vacA genotype. Both s1a/m2 vacA genotype and babA2 are associated with PUD. The study shows that different virulence attributes of H. pylori are involved in different gastroduodenal disorders.

Helicobacter pylori and recurrent pain abdomen.

OBJECTIVE: Pain abdomen is a common problem in childhood. Many factors i.e., organic changes in the gut, psychological and environment contribute to recurrent pain abdomen (RAP) in children. Helicobacter pylori infects children very early in childhood and stays indefinitely in the gut without its eradication. It may be responsible for pain abdomen and peptic ulcers in children. This study was done to assess the HP status in children with RAP diagnosed and evaluate the effects of eradication of HP infection in them. METHODS: 76 children were included in the study. RESULT: Out of 76 children studied 14.8% had evidence of a secondary cause for pain abdomen and responded to appropriate therapy. 65.45% of children who had undergone UGIE, had evidence of HP infection in the upper gastrointestinal tract. Most of these children responded to HP eradication therapy by becoming free of abdominal pain after the eradication therapy with OCA or OMA regimen. We could not do repeated endoscopies in all of them to prove the eradication due to parents' refusal and this is the main drawback of this study. CONCLUSION: However, in view of clinical response to HP eradication therapy in almost all the cases, we strongly advocate this therapy for those children with RAP, in whom HP infection of the upper gastrointestinal tract can be established beyond doubt.

Use of serology, the urease test & histology in diagnosis of Helicobacter pylori infection in symptomatic & asymptomatic Indians.

Age-specific prevalence of IgA and IgG antibodies in 714 subjects without gastrointestinal complaints aged 6 months to 90 yr was measured by an enzyme linked immunoassay using an acid-glycine extract of H. pylori as the antigen. The urease test and histology were used for the diagnosis of H. pylori infection in 83 subjects with a clinical diagnosis of dyspepsia, and these results were compared with measurement of IgG, IgA and IgM antibodies. The age specific prevalence of IgG and IgA antibodies respectively was 57 and 43 per cent for subjects aged 6 months to 4 yr and showed an increase with age to a maximum of 90 per cent for IgG in subjects > 60 yr of age and to 87 per cent for IgA in subjects between 51 and 60 yr. In symptomatic patients, there was a high degree of correlation between severity of H. pylori infection on histopathological examination and IgG (P < 0.02) levels. The use of IgG and IgA estimation could have identified H. pylori infection without endoscopy in 50 of the 83 patients. Serology for IgG and IgA antibodies against H. pylori may play a major role in decreasing the need for endoscopy, but cut-off values must be determined for each assay based on the prevalence of antibodies in the population.

Relative merits of various rapid biopsy urease tests for diagnosis of Helicobacter pylori (Campylobacter pylori).

Three rapid urease tests, i.e., liquid urea broth containing phenol red as indicator, liquid urea broth containing bromothymol blue as indicator and CLO gel were compared in 109 patients of dyspepsia for the diagnosis of Campylobacter pylori (Helicobacter pylori) infection. Mean time taken for positive reaction in liquid broth with phenol was 3 minutes (range 0.6 to 5.3 minutes) with bromothymol blue was 3.5 minutes (range 0.4 to 5.5 minutes) while with CLO gel it was 101 minutes (range 11-261 minutes). There was no difference in results of liquid urea broth containing phenol red and bromothymol blue. The difference in timing of urea broth containing phenol red and bromothymol blue was statistically significant as compared to CLO gel (p less than 0.05). Rapid urease tests employing liquid urea broth are quick, simple and reliable for the diagnosis of Helicobacer pylori infection.

Unusual features of Helicobacter (Campylobacter) pylori--associated gastritis in India. A study of 200 cases.

Helicobacter (Campylobacter) pylori has been cultured from the antral biopsies of 85-90% of patients of gastritis, gastric ulcer and duodenal ulcer at different centres. Studies conducted all over the world have firmly implicated this organism in the aetiology of active superficial gastritis and recurrences of duodenal ulcer. Two hundred patients with upper abdominal pain, distension, vomiting and/or haemetemesis were subjected to OGD scopy. In 163 of these patients there was endoscopic evidence of gastritis; in 24 there was DU; in 3, GU and in 10 it was normal. Diagnosis of H pylori infection was made by the rapid biopsy urease test which is nearly 100% specific and 98% sensitive. 170 out of 200 patients were positive for H pylori. Among these were 138 patients of gastritis (84.6%); 22 cases of DU (91.6%); 2 cases of GU (66.6%) and 8 in whom endoscopy was normal. Histological examination of the antral biopsy specimens showed mild to severe infiltration of mucosa with lymphocytes and plasma cells. None of the 170 H pylori positive cases showed polymorphonuclear infiltration which has been stressed repeatedly by most Western authors to be characteristic of "active" superficial gastritis associated with H pylori infection. Even in those with a history of dyspepsia of barely 4 weeks duration or less there was no PMN infiltration in the mucosa. Thus the local response to infection by H pylori of the gastric mucosa is different in Indian patients.

Rapid diagnostic test of Campylobacter pylori infection in patients of gastritis, duodenal ulcer and gastric ulcer. A study of 100 cases.

Campylobacter pylori has been cultured from 85-90% of antral biopsies of patients of gastritis, duodenal ulcer and gastric ulcer at different centres in the world. It has been now firmly implicated in the aetiology of active gastritis as well as suspected to cause repeated recurrences of peptic ulcers. However, the organism is very fastidious and is difficult to grow by standard culture methods as a result of which low positivity is often obtained even in well equipped centres. The rapid biopsy urease test for the diagnosis of C pylori infection, in which the biopsy is directly cultured in a solid medium containing urea, is a very simple test. A change in colour indicates the growth of the organism. This test is 100% specific and 98% sensitive. We performed this test in 100 patients; 93 of gastritis, 6 of DU and 1 of GU during a three month period. 87 of 93 cases of gastritis (90%) and all 6 cases of DU (100%) were positive. The single case of gastric ulcer was negative. Treatment of C pylori positive cases showed that they responded poorly to 4 weeks therapy with tinidazole; 33% were cured after 2 weeks of 1.5 g amoxycillin daily, but all responded when the therapy was continued for 4 weeks.