Helicobacter pylori infection is associated with a high incidence of intestinal metaplasia in the gastric mucosa of patients at inner-city hospitals in New York.

ABSTRACT

Gastric carcinogenesis is a multistep process progressing from chronic gastritis, through glandular atrophy (GA), intestinal metaplasia (IM) and dysplasia. Infection of the stomach with H. pylori increases the risk of developing gastric cancer. Few studies have examined the degree to which Hp-induced changes occur in specific populations. In the present study, we examined the association between Hp infection and histological changes in the gastric mucosa of patients at two inner-city hospitals in New York. Patients enrolled in this study were undergoing endoscopy for gastrointestinal complaints. One antral biopsy was taken for detecting and genotyping Hp by PCR. Additional biopsies were taken from the antrum and fundic region for histological analysis and were scored with respect to acute and chronic inflammation, GA, IM and Hp infestation according to the Sydney classification. Hp strains infecting these patients were genotyped with respect to the expression of Hp virulence factors including VacA, CagA, and BabA2. Samples were collected from 126 patients at Kings County Hospital in Brooklyn and St. John's Episcopal Hospital in Queens. Hp infection rates were highest in Blacks (41.6%) and Hispanics (29.4%) and lowest in Caucasians (18.8%). Scores for acute and chronic inflammation and IM were higher in Hp-infected individuals in both the antrum and fundic regions, whereas Hp infection did not affect the incidence or intensity of GA. In Hp-infected individuals, the incidence of IM was greater in the antrum (Hp-infected 37.8% vs. non-infected 9.2%, p < 0.05) and fundic region (Hp-infected 15.1% vs. noninfected 1.8%, p < 0.05). Genotyping of the Hp strains infecting these patients revealed that the predominant VacA allele was s1 bm 1 and that the CagA gene was present in 69.8% of Hp-infected samples. Interestingly, the BabA2 gene was detected in only four samples (9.3%). The incidence of IM in the antrum was higher in CagA + samples when compared with CagA- samples (52.2% vs. 15.4%, respectively). Our findings indicate that the virulent Hp strain infecting minority patients treated at inner-city hospitals in New York City is associated with a high incidence of IM and that these patients may be at greater risk for developing gastric cancer than the general population.