Importance in diagnosis of gastritis of detection by PCR of the cagA gene in Helicobacter pylori strains isolated from children

Abstract

The cagA gene has been detected by PCR and DNA hybridization in 45 Helicobacter pylori strains isolated from children. For each child, clinical symptoms, endoscopic aspect of the gastric mucosa, and histological gastritis were evaluated. Gene-positive strains were associated with hemorrhagic gastritis in 66.6% of the children, while gene-negative strains were associated with hemorrhagic gastritis in 11.2% of the children (P ‫؍‬ 0.0001). In addition, 88.8% of gene-positive strains were associated with severe histological gastritis (scores of 3 and 4), and gene-negative strains were collected from the gastric mucosa with the same type of infiltration of neutrophils and lymphocytes in the lamina propria in 55.5% of the children. These differences were statistically significant (P ‫؍‬ 0.017). Gene-positive strains were also isolated more frequently from children with vomiting (P ‫؍‬ 0.04), while the absence of clinical signs was not significantly different in cagA gene-positive or-negative patients. All of these observations confirmed the role of this cagA gene as a marker of gastric inflammation in children. The detection of this gene might be helpful to determine the degree of inflammation of the gastric mucosa in the absence of abdominal symptoms. We might better understand the natural history of H. pylori infection if we studied the evolution of gastritis in children with regard to the cagA gene status of isolated strains.

Helicobacter pylori and gastrointestinal symptoms in school children in Russia

“…37 It is known that the mean serum pepsinogen I level, duodenal ulcer rate, and inflammation score were significantly greater in children infected with cytotoxic H. pylori strains. 38,39 Actually, some investigators have stated that RAP was observed more frequently in pediatric patients with Cag A-positive H. pylori. 39,40 The authors explain this phenomenon by claiming that Cag A-positive strains may favor the local release of neuromediators.…”

“…38,39 Actually, some investigators have stated that RAP was observed more frequently in pediatric patients with Cag A-positive H. pylori. 39,40 The authors explain this phenomenon by claiming that Cag A-positive strains may favor the local release of neuromediators. 40 At the same time, other researchers have not found any abdominal complaints specific for Cag A-and Vac A-positive and Cag A and Vac A-negative H. pylori-infected children.…”

Molecular Typing of Helicobacter pylori by Virulence‐Gene Based Multiplex PCR and RT‐PCR Analysis

“…M olecular typing methods such as ribotyping [1] and randomly amplified polymorphic DNA (RAPD) analysis [2] have demonstrated considerable genomic diversity among Helicobacter pylori isolates. During the past few years, numerous PCR assays have been developed for the identification of specific virulence genes in H. pylori including ureA [3][4][5][6], ureC [7,8], cagA [3,4,9], vacA [10][11][12][13][14][15][16] and the 16S rRNA genes [17,18]. Recently, we have described a method for the rapid simultaneous molecular identification and subtyping of H. pylori by pyrosequencing of the 16S-rDNA variable V1 and V3 region [19].…”

Effect of cagA Status on the Sensitivity of Enzyme Immunoassay in Diagnosing Helicobacter pylori–Infected Children

“…A number of studies are available in the literature on the serum prevalence of the anti– H. pylori antibodies PGA and PGC in unselected children [12,17–19]. However, very few evaluations have been made of the prevalence of H. pylori strains in infected children or of their influence on the grade of gastritis and the circulating levels of anti– H. pylori antibodies or pepsinogens [29]. The aims of our study, therefore, were first to study in a selected population of children the H. pylori genotype and its association with the presence and degree of gastritis, abdominal pain, and the circulating anti– H. pylori antibodies, PGA and PGC.…”