title: [Lipoprotein particles LpA-I, LpA-I: A-II and LpB in coronary artery disease].
abstract: BACKGROUND
  High density lipoproteins are an heterogeneous population of particles. Two main subpopulations have been identified, one contains Apo A-I and Apo A-II and is denominated LpA-I:A-II and another one contains only Apo A-I and is denominated LpA-I.
  
  
  OBJECTIVE
  To measure the concentrations of these particles in patients with stable coronary artery disease.
  
  
  METHODS
  Serum lipids, A-I and B apolipoproteins, LpA-I, LpA-I:A-II and LpB particles were measured in 73 men aged 33 to 82 years with angiographically documented coronary artery disease (CAD) and 33 control subjects aged 39 to 76 years. LpA-I, LpA-I:A-II and LpB were measured by a noncompetitive enzyme linked immunoassay using previously characterized monoclonal antibodies against ApoA-I, ApoA-II and apoB.
  
  
  RESULTS
  Patients with CAD had significantly higher mean levels of LDL cholesterol than the control group (p = 0.038). The mean concentration of LpA-I particles in patients with CAD was significantly lower (p = 0.031) than in control subjects, while the concentration of LpA-I:A-II particles was significantly higher (p = 0.016). The percentage of coronary stenosis correlated negatively with LpA-I and positively with LpA-I:A-II. The best relative risk (RR) indicator in these patients was LDL-cholesterol. The relative risk increases 2.5 fold when LpA-I falls below the cut-off level. Likewise, the relative risk increases 3-fold when LpA-I:A-II raises over the cut-off level.
  
  
  CONCLUSIONS
  Our findings indicate that the quantification of LpA-I and LpA-I:A-II particles might allow a more accurate evaluation of the CAD risk than HDL cholesterol. LpA-I might represent the antiatherogenic fraction of HDL.
authors.affiliation: Departamento de Bioquímica Clínica e Inmunología, Facultad de Farmacia, Universidad de Concepción, Chile. ecalvo@udec.cl
authors.forename: C
authors.initials: C
authors.lastname: Calvo
authors.forename: A
authors.initials: A
authors.lastname: Olmos
authors.forename: N
authors.initials: N
authors.lastname: Ulloa
authors.forename: A
authors.initials: A
authors.lastname: Bustos
authors.forename: L
authors.initials: L
authors.lastname: Toledo
authors.forename: D
authors.initials: D
authors.lastname: Durán
authors.forename: R
authors.initials: R
authors.lastname: Naveas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001054:Apolipoproteins A / Q000097:blood*; D001055:Apolipoproteins B / Q000097:blood*; D016022:Case-Control Studies; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003327:Coronary Disease / Q000097:blood* / Q000209:etiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D018709:Statistics, Nonparametric
chemical_list: D001054:Apolipoproteins A; D001055:Apolipoproteins B; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL