title: Influence of age and carriage status on salivary IgA to Neisseria meningitidis.
abstract: Asymptomatic carriage of Neisseria meningitidis is common (5-35% of individuals) while the incidence of invasive meningococcal disease is fairly low (<1-5 per 100,000 per annum in Europe). Naturally acquired protective immunity may account for this difference. In this study, we investigated the relationship between anti-meningococcal salivary IgA and age and carriage. We showed that salivary IgA to a range of meningococcal antigens increased successively with age with some specificity for commonly circulating serosubtypes. In a group of 258 students 37 (14%) of whom were carriers of N. meningitidis serogroup B, higher levels of specific IgA were associated with carriage. Stratified analysis revealed a positive relationship between smoking and specific anti- N. meningitidis IgA independent of current carriage, weighted odds ratio (OR) 4.1 (95% CI 1.1-18) and OR 3.8 (95% CI 0.96-16) for reference strains B:1:P1.14 and B:4:P1.5,4 respectively. These data implicate IgA as a factor in host defence from meningococcal invasion, although the precise mechanisms remain uncertain.
authors.affiliation: Department of Pathology and Microbiology, School of Medical Sciences, University of Bristol, and Health Protection Agency, Bristol, UK. Rachel.Horton@bristol.ac.uk
authors.forename: R E
authors.initials: RE
authors.lastname: Horton
authors.forename: J
authors.initials: J
authors.lastname: Stuart
authors.forename: H
authors.initials: H
authors.lastname: Christensen
authors.forename: R
authors.initials: R
authors.lastname: Borrow
authors.forename: T
authors.initials: T
authors.lastname: Guthrie
authors.forename: V
authors.initials: V
authors.lastname: Davenport
authors.forename: A
authors.initials: A
authors.lastname: Finn
authors.forename: N A
authors.initials: NA
authors.lastname: Williams
authors.forename: R S
authors.initials: RS
authors.lastname: Heyderman
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002353:Carrier State / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D007223:Infant; D008297:Male; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000209:etiology / Q000276:immunology* / Q000517:prevention & control / Q000635:transmission*; D008875:Middle Aged; D038541:Neisseria meningitidis, Serogroup B / Q000276:immunology*; D012463:Saliva
chemical_list: D007071:Immunoglobulin A, Secretory