title: Association of small dense LDL serum levels and circulating monocyte subsets in stable coronary artery disease.
abstract: OBJECTIVE
  Atherosclerosis is considered to be an inflammatory disease in which monocytes and monocyte-derived macrophages play a key role. Circulating monocytes can be divided into three distinct subtypes, namely in classical monocytes (CM; CD14++CD16-), intermediate monocytes (IM; CD14++CD16+) and non-classical monocytes (NCM; CD14+CD16++). Low density lipoprotein particles are heterogeneous in size and density, with small, dense LDL (sdLDL) crucially implicated in atherogenesis. The aim of this study was to examine whether monocyte subsets are associated with sdLDL serum levels.
  
  
  METHODS
  We included 90 patients with angiographically documented stable coronary artery disease and determined monocyte subtypes by flow cytometry. sdLDL was measured by an electrophoresis method on polyacrylamide gel.
  
  
  RESULTS
  Patients with sdLDL levels in the highest tertile (sdLDL≥4mg/dL;T3) showed the highest levels of pro-inflammatory NCM (15.2±7% vs. 11.4±6% and 10.9±4%, respectively; p<0.01) when compared with patients in the middle (sdLDL=2-3mg/dL;T2) and lowest tertile (sdLDL=0-1mg/dL;T1). Furthermore, patients in the highest sdLDL tertile showed lower CM levels than patients in the middle and lowest tertile (79.2±8% vs. 83.9±7% and 82.7±5%; p<0.01 for T3 vs. T2+T1). Levels of IM were not related to sdLDL levels (5.6±4% vs. 4.6±3% vs. 6.4±3% for T3, T2 and T1, respectively). In contrast to monocyte subset distribution, levels of circulating pro- and anti-inflammatory markers were not associated with sdLDL levels.
  
  
  CONCLUSIONS
  The atherogenic lipoprotein fraction sdLDL is associated with an increase of NCM and a decrease of CM. This could be a new link between lipid metabolism dysregulation, innate immunity and atherosclerosis.
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Konstantin A
authors: KA
authors: Krychtiuk
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Stefan P
authors: SP
authors: Kastl
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Stefan
authors: S
authors: Pfaffenberger
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Max
authors: M
authors: Lenz
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Sebastian L
authors: SL
authors: Hofbauer
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Anna
authors: A
authors: Wonnerth
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Lorenz
authors: L
authors: Koller
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Katharina M
authors: KM
authors: Katsaros
authors: Krankenanstalten Dr. Dostal, Saarplatz 9, 1190, Vienna, Austria.
authors: Thomas
authors: T
authors: Pongratz
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Georg
authors: G
authors: Goliasch
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Alexander
authors: A
authors: Niessner
authors: 2nd Department of Internal Medicine, Faculty of Medicine, Comenius University, Vajanského nábrežie, 811 02, Bratislava, Slovakia.
authors: Ludovit
authors: L
authors: Gaspar
authors: Ludwig Boltzmann Cluster for Cardiovascular Research, Waehringerguertel 18-20, 1090, Vienna, Austria; 3rd Medical Department, Wilhelminenhospital, Montleartstraße 37, 1160, Vienna, Austria.
authors: Kurt
authors: K
authors: Huber
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Gerald
authors: G
authors: Maurer
authors: Krankenanstalten Dr. Dostal, Saarplatz 9, 1190, Vienna, Austria.
authors: Elisabeth
authors: E
authors: Dostal
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria; Ludwig Boltzmann Cluster for Cardiovascular Research, Waehringerguertel 18-20, 1090, Vienna, Austria; Core Facilities, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Johann
authors: J
authors: Wojta
authors: Krankenanstalten Dr. Dostal, Saarplatz 9, 1190, Vienna, Austria; 2nd Department of Internal Medicine, Faculty of Medicine, Comenius University, Vajanského nábrežie, 811 02, Bratislava, Slovakia.
authors: Stanislav
authors: S
authors: Oravec
authors: Department of Internal Medicine II-Division of Cardiology, Medical University of Vienna, Waehringerguertel 18-20, 1090, Vienna, Austria.
authors: Walter S
authors: WS
authors: Speidl
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000097:blood* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000473:pathology*
chemical_list: D015415:Biomarkers; D008077:Lipoproteins, LDL