摘要AIM: To determine the concentration of α- and β-defensins in gastric juice of patients with various gastroduodenal diseases.METHODS: Concentrations of human neutrophil peptides (HNPs) 1-3, the major forms of α-defensins, and human β-defensin (HBD)-1 and HBD-2 were measured by radioimmunoassay in plasma and gastric juice of 84 subjects,consisting of 54 Helicobacter pylori-infected and 30 uninfected subjects. They included 33 patients with chronic gastritis (CG),12 with gastric ulcer (GU), 11 with duodenal ulcer (DU), 11with benign gastric polyp (BGP) and 16 with normal mucosa (N group) on upper endoscopy. Plasma pepsinogen Ⅰ and Ⅱ levels, biomarkers for gastric mucosal inflammation and atrophy, were also measured.RESULTS: Gastric juice HNPs 1-3 levels in patients with CG, GU and BGP were significantly higher than those in patients with DU and N. Gastric juice HBD-2 concentrations in patients with CG and GU were significantly higher than those in the N group, but were significantly lower in DU patients than in GU patients. Gastric juice HBD-1 levels and plasma levels of these peptides were similar in the patient groups.Concentrations of gastric juice HNPs 1-3 and HBD-2 of in Hpylori-infected patients were significantly different from those in uninfected subjects. HNPs 1-3 concentrations in gastric juice correlated negatively with plasma pepsinogen I levels and Ⅰ/Ⅱ ratios. HBD-2 levels in gastric juice correlated positively and negatively with plasma pepsinogen Ⅱ concentrations and Ⅰ/Ⅱ ratios, respectively.CONCLUSION: HNPs 1-3 and HBD-2 levels in gastric juice are diverse among various gastrointestinal diseases, reflecting the inflammatory and atrophic events of the background gastric mucosa affected by H pylorri.