title: A role for archaeal organisms in development of atherosclerotic vulnerable plaques and myxoid matrices.
abstract: OBJECTIVE
  Vulnerable plaques are characterized by a myxoid matrix, necrotic lipidic core, reactive oxygen species, and high levels of microorganisms. Aerobic microbes such as Chlamydophila pneumoniae and Mycoplasma pneumoniae usually do not survive in oxidative stress media. Archaea are anaerobic microbes with powerful anti-oxidative enzymes that allow detoxification of free radicals whose presence might favor the survival of aerobic microorganisms. We searched for archaeal organisms in vulnerable plaques, and possible associations with myxoid matrix, chlamydia, and mycoplasma bodies.
  
  
  METHODS
  Twenty-nine tissue samples from 13 coronary artherectomies from large excentric ostial or bifurcational lesions were studied using optical and electron microscopy. Infectious agents compatible with archaea, chlamydia, and mycoplasma were semiquantified using electron micrographs and correlated with the amounts of fibromuscular tissue, myxoid matrix, and foam cells, as determined from semi-thin sections. Six of the cases were also submitted to polymerase chain reaction with archaeal primers.
  
  
  RESULTS
  All 13 specimens showed archaeal-compatible structures and chlamydial and mycoplasmal bodies in at least 1 sample. There was a positive correlation between extent of the of myxoid matrix and archaeal bodies (r = 0.44, P = 0.02); between archaeal and mycoplasmal bodies (r = 0.41, P = 0.03), and between chlamydial bodies and foam cells (r = 0.42; P = 0.03). The PCR test was positive for archaeal DNA in 4 of the 6 fragments.
  
  
  CONCLUSIONS
  DNA and forms suggestive of archaea are present in vulnerable plaques and may have a fundamental role in the proliferation of mycoplasma and chlamydia. This seems to be the first description of apparently pathogenic archaea in human internal organ lesions.
authors.affiliation: Heart Institute, Hospital das Clínicas, São Paulo University Medical School, São Paulo, SP, Brazil.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Higuchi
authors.forename: Marilia H
authors.initials: MH
authors.lastname: Santos
authors.forename: Alessandra
authors.initials: A
authors.lastname: Roggério
authors.forename: Joyce T
authors.initials: JT
authors.lastname: Kawakami
authors.forename: Hiram G
authors.initials: HG
authors.lastname: Bezerra
authors.forename: Mauro
authors.initials: M
authors.lastname: Canzian
mesh_terms: D000368:Aged; D000818:Animals; D001105:Archaea / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D016993:Chlamydophila pneumoniae / Q000302:isolation & purification* / Q000648:ultrastructure; D003324:Coronary Artery Disease / Q000382:microbiology* / Q000473:pathology; D004269:DNA, Bacterial; D005260:Female; D005487:Foam Cells / Q000648:ultrastructure; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009177:Mycoplasma pneumoniae / Q000302:isolation & purification* / Q000648:ultrastructure; D009336:Necrosis / Q000473:pathology; D016133:Polymerase Chain Reaction; D017382:Reactive Oxygen Species / Q000302:isolation & purification; D018709:Statistics, Nonparametric
chemical_list: D004269:DNA, Bacterial; D008055:Lipids; D017382:Reactive Oxygen Species