title: Association of Chlamydia pneumoniae infection with HLA-B*35 in patients with coronary artery disease.
abstract: The immune system may interplay between Chlamydia pneumoniae infection and coronary artery disease (CAD). Major histocompatibility complex genes regulate innate and adaptive immunity. Patients with CAD (n = 100) and controls (n = 74) were enrolled. Human leukocyte antigens (HLA-A, HLA-B, and HLA-DRB1), four lymphotoxin alpha single-nucleotide polymorphisms, and complement C4A and C4B allotypes were typed, and their haplotypes were inferred. The presence of serum C. pneumoniae immunoglobulin A (IgA) (titer, > or =40) or IgG (titer, > or =128) antibodies or immune complex (IC)-bound IgG antibodies (titer, > or =2) was considered to be a serological marker suggesting chronic C. pneumoniae infection. C. pneumoniae IgA antibodies were found more frequently in patients than in controls (P = 0.04). Among the patients, multiple logistic regression analysis showed the HLA-B*35 allele to be the strongest-risk gene for C. pneumoniae infection (odds ratio, 7.88; 95% confidence interval, 2.44 to 25.43; P = 0.0006). Markers of C. pneumoniae infection were found more frequently in patients with the HLA-A*03-B*35 haplotype than in those without the haplotype (P = 0.007 for IgA; P = 0.008 for IgG; P = 0.002 for IC). Smokers with HLA-B*35 or HLA-A*03-B*35 had markers of C. pneumoniae infection that appeared more often than in smokers without these genes (P = 0.003 and P = 0.001, respectively). No associations were found in controls. In conclusion, HLA-B*35 may be the link between chronic C. pneumoniae infection and CAD.
authors.affiliation: Division of Cardiology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Anil
authors.initials: A
authors.lastname: Palikhe
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Lokki
authors.forename: Pekka
authors.initials: P
authors.lastname: Saikku
authors.forename: Maija
authors.initials: M
authors.lastname: Leinonen
authors.forename: Mika
authors.initials: M
authors.lastname: Paldanius
authors.forename: Mikko
authors.initials: M
authors.lastname: Seppänen
authors.forename: Ville
authors.initials: V
authors.lastname: Valtonen
authors.forename: Markku S
authors.initials: MS
authors.lastname: Nieminen
authors.forename: Juha
authors.initials: J
authors.lastname: Sinisalo
mesh_terms: D000918:Antibody Specificity; D023521:Chlamydophila Infections / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D003324:Coronary Artery Disease / Q000276:immunology* / Q000382:microbiology*; D005260:Female; D015797:HLA-B35 Antigen / Q000097:blood / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000276:immunology
chemical_list: D015797:HLA-B35 Antigen; D007070:Immunoglobulin A; D007074:Immunoglobulin G