title: Chlamydial LPS antibodies, intima-media thickness and ischemic events in patients with established atherosclerosis.
abstract: BACKGROUND
  Chlamydia pneumoniae has been associated with cardiovascular disease. However, studies on the presence of chlamydial antibodies and intima-media thickness (IMT) or future ischemic events are inconclusive. We examined the relation between circulating antibodies to chlamydial lipopolysaccharide (cLPS Ab), IMT and the occurrence of ischemic events during follow-up in patients with manifest atherosclerotic disease.
  
  
  METHODS
  IgG and IgA antibodies against cLPS were determined in 273 out of 307 consecutive patients with a recent ischemic stroke (IS, n=90), a recent myocardial infarction (MI, n=87) or peripheral arterial disease (PAD, n=96). B-mode ultrasound IMT measurement of carotid and femoral arteries was performed and ischemic events, IS or MI, during follow-up were registered.
  
  
  RESULTS
  IgG and IgA were found in 66 and 46% of the patients, respectively. We did not detect any difference in IMT between patients with or without antibodies: IgA-0.97(0.28) mm versus IgA+0.95(0.26) mm, P=0.63, IgG-0.96(0.28) mm versus IgG+0.96(0.26) mm, P=0.98. During follow-up with a mean duration of 3.5 years the combined endpoint, MI or IS, was similar in patients with or without antibodies (IgA-24% vs. IgA+19%, IgG-23% vs. IgG+22%). However, a lower frequency of MI was observed in IgA positive patients (IgA-13% vs. IgA+8%). The number of ischemic events in the 12 patients who used anti-chlamydial antibiotics was similar compared with those who did not use antibiotics.
  
  
  CONCLUSIONS
  In patients with manifest atherosclerotic disease no association between the presence of cLPS Ab and IMT could be detected. In addition, no influence of cLPS Ab on the number of ischemic events was observed, the frequency of MI during follow-up in IgA positive patients was even lower.
authors.affiliation: Department of Internal Medicine, Slotervaart Hospital, Louwesweg 6, 1066 EC, Amsterdam, The Netherlands. igvge@slz.nl
authors.forename: Victor E A
authors.initials: VE
authors.lastname: Gerdes
authors.forename: Roel P
authors.initials: RP
authors.lastname: Verkooyen
authors.forename: Vincent I H
authors.initials: VI
authors.lastname: Kwa
authors.forename: Eric
authors.initials: E
authors.lastname: de Groot
authors.forename: Eric C M
authors.initials: EC
authors.lastname: van Gorp
authors.forename: Hugo
authors.initials: H
authors.lastname: ten Cate
authors.forename: Dees P M
authors.initials: DP
authors.lastname: Brandjes
authors.forename: Harry R
authors.initials: HR
authors.lastname: Büller
mesh_terms: D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis*; D001161:Arteriosclerosis / Q000276:immunology* / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D008070:Lipopolysaccharides / Q000032:analysis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000276:immunology / Q000473:pathology; D016491:Peripheral Vascular Diseases / Q000276:immunology / Q000473:pathology; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D012680:Sensitivity and Specificity; D020521:Stroke / Q000276:immunology / Q000473:pathology; D017539:Tunica Intima / Q000276:immunology* / Q000473:pathology
chemical_list: D000907:Antibodies, Bacterial; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008070:Lipopolysaccharides