title: [Chlamydia pneumoniae in coronary plaques: Increased detection with acute coronary syndrome].
abstract: OBJECTIVE
  There is seroepidemiologic and experimental evidence for a link between Chlamydia (C.) pneumoniae and arteriosclerosis. However, the clinical importance and the pathogenic pathways implicated remain unclear. In the present study, we sought to evaluate the presence and the location of C. pneumoniae in coronary atheroma, as well as a potential prevalence with unstable versus stable angina.
  
  
  METHODS
  Retrospectively, coronary plaque material of primary lesions from 51 consecutive patients (44 men, 7 women, mean age 59.6 +/- 9.4 years) was examined for the presence of C. pneumoniae by use of immuno-histochemistry and transmission electron microscopy. The findings associated with clinically acute coronary syndrome according to Braunwald's classification (n = 31) were compared to those with stable angina (n = 20) and regarded for potential relations to characteristic intimal features.
  
  
  RESULTS
  Immunoreaction for C. pneumoniae was found in 32 of 51 (63%) coronary plaques. Signals (% prevalence of specific intimal features) were present with necrotic areas (40%), sparse cellularity (40%), neo-vascularization (29%), thrombi (20%), ruptured plaque areas (19%), and fields rich in foam cells and calcifications (13%). Intimal hyperplasia and inflammatory infiltrates showed no signals. As the central finding in this report, C. pneumoniae immunoreaction was more frequently (P < 0.001) found in 26 of 31 (84%) lesions associated with unstable angina or acute myocardial infarction, compared to 6 of 20 (30%) lesions with stable angina (P < 0.001). Intact vessels devoid of arteriosclerotic disease, such as mammarial arteries and saphenous veins, were without C. pneumoniae signals (negative controls). Ultrastructurally, chlamydial elementary bodies were found in foam cells and phagocytosing macrophages, also in fragmented extracellular matrix adjacent to apoptotic and necrotic intimal cells.
  
  
  CONCLUSIONS
  Chlamydiae pneumoniae were detected in 32 of 51 (63%) coronary primary lesions of symptomatic patients. Most importantly, there was a highly significant prevalence of lesions associated with acute coronary syndrome. Predilection sites of C. pneumoniae were areas that revealed small healing activity and (or) propensity to plaque rupture. The present in situ findings indicate a pathogenic role of Chlamydiae pneumoniae in human (coronary) plaque rupture.
authors.affiliation: Medizinische Klinik und Poliklinik II, Universität Bonn.
authors.forename: G
authors.initials: G
authors.lastname: Bauriedel
authors.forename: U
authors.initials: U
authors.lastname: Welsch
authors.forename: J A
authors.initials: JA
authors.lastname: Likungu
authors.forename: A
authors.initials: A
authors.lastname: Welz
authors.forename: B
authors.initials: B
authors.lastname: Lüderitz
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000382:microbiology*; D000789:Angina, Unstable / Q000382:microbiology*; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification*; D003324:Coronary Artery Disease / Q000382:microbiology*; D005109:Extracellular Matrix / Q000382:microbiology / Q000648:ultrastructure; D005260:Female; D005487:Foam Cells / Q000382:microbiology / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000382:microbiology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D012189:Retrospective Studies