A clinical analysis of the relationship between the types of Helicobacter pylori strains and chronic upper gastrointestinal diseases

Objective To explore the relationship of the types of Helicobacter pylori(H.pylori)strains with the severity of chronic gastroduodenal diseases.Methods 198 H.pylori-positive patients confirmed by gastroscopy were enrolled in this study.H.pylori strains were serotyped by immunoblot technique.The gastric biopsy specimens from all patients were examined histologically.Results Type Ⅰ and type Ⅱ H.pylori strains were detectable in 173(87.4%)and 25 patients(12.6%),respectively.The incidence of peptic ulcer and that of gastric cancer were higher in patients with type Ⅰ H.pylori infection than in those with type Ⅱ infection(P = 0.012).A higher rate of type I infection was found in patients with duodenal ulcer or gastric cancer than in those with chronic gastritis(P = 0.026 and P = 0.048,respectively)while type Ⅰ infection did not differ significantly between gastric ulcer and chronic gastritis(P = 0.125).Type Ⅰ H.pylori infection resulted in more severe pathohistologic changes of the gastric mucosa than did type Ⅱ infection(P = 0.038).Conclusions Type Ⅰ strains are the leading pathogen of H.pylori infection.The serotyping of H.pylori strains is helpful in judging the severity of chronic upper gastrointestinal diseases.Those with type Ⅰ H.pylori infection should be treated more aggressively.