title: Lipoprotein remnants and dense LDL are associated with features of unstable carotid plaque: a flag for non-HDL-C.
abstract: OBJECTIVE
  We investigated the association between cholesterol across the LDL density range and in the VLDL and IDL particles with the prevalence of inflammatory cells in plaques of patients with severe carotid artery stenosis.
  
  
  METHODS
  Forty-five patients undergoing carotid endarterectomy were studied. Plaque specimens were analyzed for cellular composition by immunocytochemistry using monoclonal antibodies. Lipoprotein subclasses were separated by gradient ultracentrifugation.
  
  
  RESULTS
  We found no correlations between LDL-C, HDL-C and plasma triglyceride levels with plaque cellular composition. On the other hand, macrophage content was significantly related to cholesterol in the dense LDL subclasses (r = 0.30, p < 0.01) and in the triglyceride-rich lipoprotein remnants, namely dense VLDL and IDL particles (r = 0.46, p < 0.01). HDL subclasses were not correlated with plaque cellular composition. In a mirror manner, smooth muscle cells were inversely associated with cholesterol levels of the dense LDL subclasses (r = -0.32, p < 0.01 fraction 10; r = -0.26, p < 0.05 fraction 11) while only a non-significant trend was observed with the cholesterol in the VLDL-IDL fractions. These results provide the pathophysiological background to account for the relevance of non-HDL-C as the only lipid parameter, aside LDL density, significantly associated (β = 0.351, p = 0.021) with carotid plaque macrophage content.
  
  
  CONCLUSIONS
  We provide evidence that lipoprotein subclasses, specifically cholesterol in the dense LDL fractions and in the triglyceride-rich lipoprotein remnants, significantly affect carotid plaque cellular composition, in particular macrophages content.
authors: Clinica Medica, Department of Medicine - DIMED, University of Padova, Italy.
authors: Alberto
authors: A
authors: Zambon
authors: Massimo
authors: M
authors: Puato
authors: Elisabetta
authors: E
authors: Faggin
authors: Franco
authors: F
authors: Grego
authors: Marcello
authors: M
authors: Rattazzi
authors: Paolo
authors: P
authors: Pauletto
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal / Q000737:chemistry; D016893:Carotid Stenosis / Q000097:blood* / Q000473:pathology*; D002784:Cholesterol / Q000097:blood / Q000737:chemistry; D008076:Cholesterol, HDL / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation; D008074:Lipoproteins / Q000737:chemistry; D008077:Lipoproteins, LDL / Q000097:blood*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D013696:Temperature; D014280:Triglycerides / Q000097:blood; D014461:Ultracentrifugation
chemical_list: D000911:Antibodies, Monoclonal; D008076:Cholesterol, HDL; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002784:Cholesterol
keywords: Carotid plaque; Inflammation; LDL density; Lipoprotein remnants; Macrophages; Non-HDL-C