title: Gastric carcinoid tumors without autoimmune gastritis in Japan: a relationship with Helicobacter pylori infection.
abstract: In Japan, most cases of gastric carcinoid tumor (GCT) are unassociated with either autoimmune gastritis (AIG) showing type-A chronic atrophic gastritis (CAG-A) or Zollinger-Ellison syndrome (ZES). However, the pathogenesis of this tumor remains unknown. Recent studies have determined that Helicobacter pylori infection induces gastric carcinoid in Mongolian gerbils and that H. pylori lipopolysaccharide exerts a mitogenic effect on ECL cells. We examined five patients with histologically diagnosed GCT, 40 patients with H. pylori-positive gastric ulcer (Hp+GU), 24 patients with H. pylori-positive duodenal ulcer (Hp+DU), and 12 patients with AIG showing CAG-A topographically. We compared the prevalence of H. pylori infection, and the levels of gastrin and pepsinogen (PG) in the serum of patients with GCT with those of patients with Hp+GU, or Hp+DU, and AIG. We also investigated the histological characteristics of the tumor and the gastric corpus mucosa in the GCT patients. The levels of serum gastrin and PG I and II were measured using an RIA kit. In all five (100%) patients with GCT, H. pylori infection was present, without any evidence of AIG or ZES. The serum levels of gastrin in the GCT patients were higher than those in either Hp+GU or Hp+DU patients and lower than those in the AIG patients. In contrast, serum PG I levels and the PG I/II ratio were lower in the GCT group than in the Hp+GU or Hp+DU groups. Histologically, all GCTs were ECL cell tumors and peritumoral corporal mucosal atrophy was observed in four of the five patients with GCT. In conclusions, H. pylori infection and hypergastrinemia were found in the patients with GCT without AIG. This finding suggests that H. pylori infection may induce corporal mucosal atrophy and hypergastrinemia that can produce a GCT with time.
authors.affiliation: Third Department of Internal Medicine, Faculty of Health Science, Niigata University School of Medicine, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sato
authors.forename: Mitsuya
authors.initials: M
authors.lastname: Iwafuchi
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Ueki
authors.forename: Akira
authors.initials: A
authors.lastname: Yoshimura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Mochizuki
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Motoyama
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Sugimura
authors.forename: Terasu
authors.initials: T
authors.lastname: Honma
authors.forename: Rintaro
authors.initials: R
authors.lastname: Narisawa
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ichida
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Asakura
authors.forename: D H
authors.initials: DH
authors.lastname: Van Thiel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000097:blood / Q000150:complications* / Q000382:microbiology; D002276:Carcinoid Tumor / Q000097:blood / Q000150:complications / Q000382:microbiology*; D004381:Duodenal Ulcer / Q000097:blood / Q000150:complications / Q000382:microbiology; D005260:Female; D005755:Gastrins / Q000097:blood; D005756:Gastritis / Q000097:blood / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D005757:Gastritis, Atrophic / Q000097:blood / Q000150:complications / Q000382:microbiology; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D020116:Pepsinogen A / Q000097:blood; D020115:Pepsinogen C / Q000097:blood; D010437:Peptic Ulcer / Q000097:blood / Q000150:complications / Q000382:microbiology; D013274:Stomach Neoplasms / Q000097:blood / Q000150:complications / Q000382:microbiology*
chemical_list: D005755:Gastrins; D020115:Pepsinogen C; D020116:Pepsinogen A