title: Endothelial- and Platelet-Derived Microparticles Are Generated During Liver Resection in Humans.
abstract: BACKGROUND
  Cell-derived plasma microparticles (<1.5 μm) originating from various cell types have the potential to regulate thrombogenesis and inflammatory responses. The aim of this study was to test the hypothesis that microparticles generated during hepatic surgery co-regulate postoperative procoagulant and proinflammatory events.
  
  
  METHODS
  In 30 patients undergoing liver resection, plasma microparticles were isolated, quantitated, and characterized as endothelial (CD31+, CD41-), platelet (CD41+), or leukocyte (CD11b+) origin by flow cytometry and their procoagulant and proinflammatory activity was measured by immunoassays.
  
  
  RESULTS
  During liver resection, the total numbers of microparticles increased with significantly more Annexin V-positive, endothelial and platelet-derived microparticles following extended hepatectomy compared to standard and minor liver resections. After liver resection, microparticle tissue factor and procoagulant activity increased along with overall coagulation as assessed by thrombelastography. Levels of leukocyte-derived microparticles specifically increased in patients with systemic inflammation as assessed by C-reactive protein but are independent of the extent of liver resection.
  
  
  CONCLUSIONS
  Endothelial and platelet-derived microparticles are specifically elevated during liver resection, accompanied by increased procoagulant activity. Leukocyte-derived microparticles are a potential marker for systemic inflammation. Plasma microparticles may represent a specific response to surgical stress and may be an important mediator of postoperative coagulation and inflammation.
authors.affiliation: a Institute of Pathology, University of Bern , Bern , Switzerland.
authors.forename: Yara
authors.initials: Y
authors.lastname: Banz
authors.affiliation: b Department for Visceral Surgery and Medicine , University of Bern , Bern , Switzerland.
authors.forename: Gian-Marco
authors.initials: GM
authors.lastname: Item
authors.affiliation: c Department of Anaesthesiology , University of Bern , Bern , Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Vogt
authors.affiliation: d Department of Clinical Research , University of Bern, Bern University Hospital , Bern , Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Rieben
authors.affiliation: b Department for Visceral Surgery and Medicine , University of Bern , Bern , Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Candinas
authors.affiliation: b Department for Visceral Surgery and Medicine , University of Bern , Bern , Switzerland.
authors.forename: Guido
authors.initials: G
authors.lastname: Beldi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017304:Annexin A5 / Q000378:metabolism; D001777:Blood Coagulation / Q000502:physiology*; D001792:Blood Platelets / Q000502:physiology*; D002097:C-Reactive Protein / Q000378:metabolism; D055252:Cell-Derived Microparticles / Q000502:physiology*; D042783:Endothelial Cells / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D006498:Hepatectomy; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D008099:Liver / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D013916:Thrombelastography
chemical_list: D017304:Annexin A5; D002097:C-Reactive Protein
keywords: Microparticles; endothelium; liver resection; patients; platelets