title: Helicobacter pylori infection as a protective factor against multiple sclerosis risk in females.
abstract: BACKGROUND
  In recent years, a relationship between Helicobacter pylori and many disease conditions has been reported, however, studies in its relationship with multiple sclerosis (MS) have had contradictory results.
  
  
  OBJECTIVE
  To determine the association between the H. pylori infection and MS.
  
  
  METHODS
  550 patients with MS were included in the study and were matched by gender and year of birth to 299 controls. Patients were assessed for clinical and demographic parameters. An enzyme immunoassay was used to detect the presence of specific IgG antibodies against H. pylori in the serum sample of both groups.
  
  
  RESULTS
  H. pylori seropositivity was found to be lower in the patients with MS than in controls (16% vs 21%) with the decrease pertaining to females (14% vs 22%, p=0.027) but not males (19% vs 20%, p=1.0). When adjusted for age at onset, year of birth and disease duration, H. pylori seropositive females presented with a lower disability score than seronegative females (p=0.049), while among males the reverse was true (p=0.025). There was no significant association between H. pylori seropositivity and relapse rate.
  
  
  CONCLUSIONS
  Our results could reflect a protective role of H. pylori in the disease development. However, it may be that H. pylori infection is a surrogate marker for the 'hygiene hypothesis', a theory which postulates that early life infections are essential to prime the immune system and thus prevent allergic and autoimmune conditions later in life. The fact that the association between H. pylori seropositivity and MS risk was seen almost exclusively in females requires further investigation.
authors.affiliation: Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, The University of Western Australia, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Australia.
authors.forename: Marzena J Fabis
authors.initials: MJ
authors.lastname: Pedrini
authors.affiliation: Department of Neurology, VU University Medical Center, Amsterdam, Netherlands.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Seewann
authors.affiliation: Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, The University of Western Australia, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Australia.
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Bennett
authors.affiliation: Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, The University of Western Australia, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Australia.
authors.forename: Alex J T
authors.initials: AJ
authors.lastname: Wood
authors.affiliation: Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: James
authors.affiliation: Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, The University of Western Australia, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Burton
authors.affiliation: The Marshall Centre for Infectious Diseases Research and Training, The University of Western Australia, QEII Medical Centre, Nedlands, Australia.
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Marshall
authors.affiliation: Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, The University of Western Australia, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Australia.
authors.forename: William M
authors.initials: WM
authors.lastname: Carroll
authors.affiliation: Centre for Neuromuscular and Neurological Disorders, Western Australian Neuroscience Research Institute, The University of Western Australia, Sir Charles Gairdner Hospital, QEII Medical Centre, Nedlands, Australia Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, Australia.
authors.forename: Allan G
authors.initials: AG
authors.lastname: Kermode
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology / Q000503:physiopathology*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000503:physiopathology*; D020528:Multiple Sclerosis, Chronic Progressive / Q000453:epidemiology / Q000503:physiopathology; D065840:Protective Factors; D012008:Recurrence; D012727:Sex Characteristics; D014904:Western Australia / Q000453:epidemiology; D055815:Young Adult
keywords: MULTIPLE SCLEROSIS