title: Low prevalence of Helicobacter pylori in individuals with HTLV-I infection.
abstract: BACKGROUND
  The prevalence of Helicobacter pylori in HIV-positive individuals is significantly lower than in HIV-negative controls. However, its prevalence in individuals infected with human T-cell leukaemia virus type I (HTLV-I), another important member of the human retrovirus family, has not been previously investigated.
  
  
  OBJECTIVE
  To establish the prevalence of H. pylori in HTLV-I-positive individuals in the Nagasaki Prefecture, which is an area endemic for HTLV-I.
  
  
  METHODS
  We examined sera from 146 HTLV-I-positive individuals with a mean age of 56.7 years, consisting of 45 adult T-cell leukaemia (ATL) patients, 13 HTLV-I-associated myelopathy (HAM) patients and 88 healthy carriers. Serum samples of 292 age- and sex-matched HTLV-I-negative controls were also examined. Serum anti-H. pylori immunoglobulin (Ig) G antibody was examined using an enzyme-linked immunosorbent assay kit. Twenty-eight HTLV-I-positive patients were examined endoscopically, assessed for H. pylori by culture, histology and CLO test using gastric biopsy specimens, and gastritis in these patients was also graded histologically.
  
  
  RESULTS
  The seroprevalence of H. pylori was 48% in HTLV-I-positive individuals versus 64% in HTLV-I-negative controls (P < 0.01). In the three HTLV-I-positive groups, ATL patients and carriers had significantly lower seroprevalence of H. pylori than the HTLV-I-negative controls (P < 0.05). Assessment of H. pylori using gastric biopsy specimens also showed a significantly lower prevalence of H. pylori infection in HTLV-I-positive patients than controls (46% versus 70%, P < 0.05). Histological examination showed a significantly higher degree of activity, inflammation and glandular atrophy in the antrum and corpus in H. pylori-positive patients compared to H. pylori-negative patients. H. pylori-positive patients with HTLV-I infection had a more severe degree of glandular atrophy in the corpus than H. pylori-positive controls without HTLV-I infection.
  
  
  CONCLUSIONS
  We have found a reduced prevalence of H. pylori in HTLV-I-positive individuals. Whatever the explanation, infection with HTLV-I does not predispose to the risk of H. pylori infection.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Isomoto
authors.forename: Y
authors.initials: Y
authors.lastname: Mizuta
authors.forename: K
authors.initials: K
authors.lastname: Fukushima
authors.forename: F
authors.initials: F
authors.lastname: Takeshima
authors.forename: M
authors.initials: M
authors.lastname: Miyazaki
authors.forename: K
authors.initials: K
authors.lastname: Murase
authors.forename: K
authors.initials: K
authors.lastname: Omagari
authors.forename: T
authors.initials: T
authors.lastname: Maeda
authors.forename: S
authors.initials: S
authors.lastname: Kamihira
authors.forename: M
authors.initials: M
authors.lastname: Tomonaga
authors.forename: S
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015490:HTLV-I Infections / Q000453:epidemiology*; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012680:Sensitivity and Specificity