title: Identification and assessment of plasma lysozyme as a putative biomarker of atherosclerosis.
abstract: OBJECTIVE
  To identify a plasma biomarker of atheromatous disease.
  
  
  RESULTS
  Surface-enhanced laser desorption ionization-time-of-flight mass spectrometry was used to identify possible plasma protein biomarkers of atheromatous disease in patients presenting with chronic stable angina pectoris by comparing those with 3-vessel disease with those without any evidence of coronary artery disease. The level of a 14.7-kDa protein was elevated; this protein was isolated and identified as a lysozyme. Arterial plasma lysozyme levels, measured by immunoassay, confirmed this observation in separate cohorts of patients. The application of arterial plasma lysozyme levels to 197 patients with varying degrees of coronary artery disease, using a cutoff value of 1.5 microg/mL, was able to distinguish patients with 1 or more occluded coronary arteries, with 86% sensitivity and 93% specificity. Of 20 patients with carotid atheroma, 19 had increased arterial plasma levels. In contrast, C-reactive protein levels showed no association with disease severity. Venous lysozyme levels in patients with carotid atheroma were shown to decrease after intensive atorvastatin treatment.
  
  
  CONCLUSIONS
  Raised plasma lysozyme levels may be a useful biomarker of atherosclerotic cardiovascular disease and response to therapy. Additional studies to investigate this are warranted.
authors.affiliation: Experimental Medicine, Imperial College London, Du Cane Road, London W12 0NN, England. vahitha.abdul-salam02@imperial.ac.uk
authors.forename: Vahitha B
authors.initials: VB
authors.lastname: Abdul-Salam
authors.forename: Punit
authors.initials: P
authors.lastname: Ramrakha
authors.forename: Unni
authors.initials: U
authors.lastname: Krishnan
authors.forename: David R
authors.initials: DR
authors.lastname: Owen
authors.forename: Joseph
authors.initials: J
authors.lastname: Shalhoub
authors.forename: Alun H
authors.initials: AH
authors.lastname: Davies
authors.forename: Tjun Y
authors.initials: TY
authors.lastname: Tang
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Gillard
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Boyle
authors.forename: Martin R
authors.initials: MR
authors.lastname: Wilkins
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Edwards
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000201:enzymology / Q000209:etiology; D000069059:Atorvastatin; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002340:Carotid Artery Diseases / Q000188:drug therapy / Q000201:enzymology*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000201:enzymology*; D005260:Female; D006538:Heptanoic Acids / Q000627:therapeutic use; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D009113:Muramidase / Q000097:blood*; D011237:Predictive Value of Tests; D011758:Pyrroles / Q000627:therapeutic use; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D011758:Pyrroles; D002097:C-Reactive Protein; D000069059:Atorvastatin; D009113:Muramidase