title: Helicobacter pylori infection in patients with gastric involvement by adult T-cell leukemia/lymphoma.
abstract: BACKGROUND
  Gastrointestinal involvement is seen frequently in patients with adult T-cell leukemia/lymphoma (ATLL). The authors previously showed a relatively low prevalence of Helicobacter pylori infection in individuals with human T-cell lymphotropic virus 1 (HTLV-1) infection, including patients with ATLL; however, the correlation between H. pylori infection and ATLL gastric involvement has not been investigated.
  
  
  METHODS
  The authors studied 71 patients with ATLL. Gastric involvement was confirmed by endoscopy and biopsy. H. pylori infection was detected by serology, rapid urease test, and immunohistochemistry on biopsy samples. The expression of adhesion molecules on ATLL cells or their ligands on the vasculature in gastric mucosa was analyzed immunohistochemically. The expression of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis.
  
  
  RESULTS
  Gastric involvement was detected in 21 patients (30%), including 8 patients with acute clinical subtype ATLL and 13 patients with lymphoma type ATLL. The prevalence of H. pylori infection was 86% (18 of 21 patients) in the patients with gastric involvement but only 38% (19 of 50 patients) in the patients without such involvement (P < 0.001). The expression of lymphocyte function-associated antigen 1 (LFA-1) and its ligand, intercellular adhesion molecule 1 (ICAM-1), was most frequent on ATLL cells infiltrating the stomach and was enhanced substantially on vascular endothelium in H. pylori-infected gastric mucosa. Human mucosal lymphocyte antigen 1 also was expressed on infiltrating ATLL cells in the stomach. The expression of MAdCAM-1 mRNA assessed by RT-PCR also was seen selectively in H. pylori-infected patients.
  
  
  CONCLUSIONS
  ATLL cells infiltrate gastric tissues infected with H. pylori, probably through the interaction of adhesion molecules on these cells and their ligands on the vasculature, i.e., through the LFA-1/ICAM-1 pathway.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University School of Medicine, Nagasaki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Ohnita
authors.forename: Hajime
authors.initials: H
authors.lastname: Isomoto
authors.forename: Yohei
authors.initials: Y
authors.lastname: Mizuta
authors.forename: Takahiro
authors.initials: T
authors.lastname: Maeda
authors.forename: Masuho
authors.initials: M
authors.lastname: Haraguchi
authors.forename: Masanobu
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Murase
authors.forename: Ikuo
authors.initials: I
authors.lastname: Murata
authors.forename: Masao
authors.initials: M
authors.lastname: Tomonaga
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000328:Adult; D000368:Aged; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000494:pharmacology; D002450:Cell Communication; D004273:DNA, Neoplasm; D005260:Female; D016481:Helicobacter Infections / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000150:complications* / Q000473:pathology; D008024:Ligands; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000150:complications / Q000556:secondary*
chemical_list: D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; D008024:Ligands; D012333:RNA, Messenger