title: Association of influenza virus infection and inflammatory cytokines with acute myocardial infarction.
abstract: OBJECTIVE
  To explore the potential relationship between previous influenza virus (IV) infection and acute myocardial infarction (AMI), and the mechanism of atherosclerosis, we conducted a case-control study and examined inflammatory cytokines to assess the association of previous IV infection and AMI.
  
  
  METHODS
  A questionnaire-based survey was conducted to collect information about demographic characteristics and heart disease risk factors. Fasting blood samples were obtained to measure immunoglobulin (Ig) G antibodies to influenza virus A (IV-A), influenza virus B (IV-B), cytomegalovirus, herpes simplex virus type-1 and type-2, adenovirus, rubella virus and Chlamydia pneumoniae, and to measure the level of certain biochemistry markers: interleukin-2, 6, 10 and 18 (IL-2, 6, 10 and 18), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), endothelin-1 (ET-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1).
  
  
  RESULTS
  Compared with the controls, the cases were more likely to have positive IgG antibodies to IV-A and IV-B [IV-A: odds ratio (OR): 3.1, 95% confidence interval (CI): 1.5-6.4; IV-B: OR: 10.2, 95% CI: 5.7-20.0]. After adjustment for potential confounding variables, the risk of AMI was still associated with the presence of IgG antibodies to IV-A (adjusted OR: 5.5, 95% CI: 1.3-23.0) and IV-B (adjusted OR: 20.3, 95% CI: 5.6-40.8). The levels of IL-2, 6, 10 and18, TNF-α, IFN-γ, ET-1, sICAM-1 and sVCAM-1 in patients with AMI were significantly higher than those of the controls (P < 0.01).
  
  
  CONCLUSIONS
  Our study supports the hypothesis that previous IV infection is associated with AMI. Inflammatory cytokines may take part in the development of atherosclerosis and trigger the occurrence of AMI.
authors.affiliation: Department of Laboratory Diagnostics, First Affiliated Hospital of Harbin Medical University, Harbin, 150001, China.
authors.forename: Xiuru
authors.initials: X
authors.lastname: Guan
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Xijuan
authors.initials: X
authors.lastname: Sun
authors.forename: Lanfeng
authors.initials: L
authors.lastname: Wang
authors.forename: Benjiang
authors.initials: B
authors.lastname: Ma
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Li
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000368:Aged; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007251:Influenza, Human / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000453:epidemiology* / Q000276:immunology; D014280:Triglycerides / Q000097:blood
chemical_list: D000914:Antibodies, Viral; D001786:Blood Glucose; D016207:Cytokines; D007074:Immunoglobulin G; D014280:Triglycerides; D002784:Cholesterol