title: Interleukin-6-174 G/C promoter polymorphism is associated with persistence of Chlamydia pneumoniae antibodies in young men.
abstract: A promoter polymorphism -174 G/C in the inflammatory cytokine interleukin-6 (IL-6) gene has been associated with differences in serum IL-6 levels and a risk for inflammatory conditions, such as cardiovascular diseases. We investigated whether this polymorphism is associated with Chlamydia pneumoniae, a common causative agent of respiratory infection with tendency for persistent infections, in 867 Finnish military recruits. IgG seropositivity in arrival and departure serum samples during 6-12 months of military service was considered as persistence of antibodies and a possible prolonged or chronic infection. The -174C allele was significantly associated with IgG seropositivity (P = 0.0002) and the persistence of IgG antibodies (P = 0.0002) as well as with slightly elevated C-reactive protein (CRP) levels (P = 0.003). In addition, the association was stronger when persistent C. pneumoniae antibodies were present together with elevated CRP than when either of them was positive alone (OR; 95% CI: 3.45; 2.00-5.98 and 1.41; 1.00-1.99, respectively). Our data suggest that IL-6 -174 G/C polymorphism is associated with persistence of C. pneumoniae antibodies and may be linked to the chronic or prolonged infection with systemic low-grade inflammation.
authors.affiliation: National Institute for Health and Welfare, Oulu, Finland. aino.rantala@oulu.fi
authors.forename: A
authors.initials: A
authors.lastname: Rantala
authors.forename: T
authors.initials: T
authors.lastname: Lajunen
authors.forename: R
authors.initials: R
authors.lastname: Juvonen
authors.forename: M
authors.initials: M
authors.lastname: Paldanius
authors.forename: S
authors.initials: S
authors.lastname: Silvennoinen-Kassinen
authors.forename: A
authors.initials: A
authors.lastname: Peitso
authors.forename: O
authors.initials: O
authors.lastname: Vainio
authors.forename: M
authors.initials: M
authors.lastname: Leinonen
authors.forename: P
authors.initials: P
authors.lastname: Saikku
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood / Q000235:genetics* / Q000276:immunology; D023521:Chlamydophila Infections / Q000276:immunology*; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D011401:Promoter Regions, Genetic; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D015850:Interleukin-6