title: Microparticles impact coagulation after traumatic brain injury.
abstract: BACKGROUND
  The pathophysiology that drives the subacute hypercoagulable state commonly seen after traumatic brain injury (TBI) is not well understood. Alterations caused by TBI in platelet and microparticle (MP) numbers and function have been suggested as possible causes; however, the contributions of platelets and MPs are currently unknown.
  
  
  METHODS
  A weight-drop technique of TBI using a murine model of moderate head injury was used. Blood was collected at intervals after injury. MP enumeration and characterization were performed using Nanoparticle Tracking Analysis, and platelet counts and coagulation parameters were determined using thromboelastometry. A MP procoagulant assay was used to compare activity between injured and sham mice.
  
  
  RESULTS
  At 24 h after injury, there were no changes in circulating platelet numbers. However, there was a decrease in platelet contribution to clot formation. In contrast, there was a decline in circulating total MP numbers. When MPs from sham mice were added to the blood from head-injured animals, there was a normalization of platelet contribution to clot formation. Conversely, when MPs from TBI mice were added to sham blood, there was a significant decrease in platelet contribution to clot formation. Notably, there was an increase in MP procoagulant activity in head-injured mice.
  
  
  CONCLUSIONS
  MPs generated after TBI likely contribute to altered coagulation after head injury and may play a key role in the development of a posttraumatic hypercoagulable state in TBI patients.
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Emily F
authors.initials: EF
authors.lastname: Midura
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Jernigan
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Kuethe
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Lou Ann
authors.initials: LA
authors.lastname: Friend
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Rosalie
authors.initials: R
authors.lastname: Veile
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Amy T
authors.initials: AT
authors.lastname: Makley
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio.
authors.forename: Charles C
authors.initials: CC
authors.lastname: Caldwell
authors.affiliation: Division of Research, Department of Surgery and Institute for Military Medicine, University of Cincinnati, Cincinnati, Ohio. Electronic address: goodmamd@ucmail.uc.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Goodman
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation / Q000502:physiology*; D001792:Blood Platelets / Q000378:metabolism*; D001930:Brain Injuries / Q000097:blood*; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010976:Platelet Count; D013916:Thrombelastography
chemical_list: D015415:Biomarkers
keywords: Hypercoagulability; Microparticles; Platelet function; TBI; Thromboelastometry
references.citation: Acta Pharmacol Sin. 2014 Sep;35(9):1103-10
references.pmid: 25152025
references.citation: Injury. 2010 Jan;41(1):97-101
references.pmid: 19608183
references.citation: J Trauma Acute Care Surg. 2012 Jun;72(6):1470-5; discussion 1475-7
references.pmid: 22695409
references.citation: J Trauma. 2005 Apr;58(4):725-9; discussion 729-30
references.pmid: 15824648
references.citation: N Engl J Med. 1996 Sep 5;335(10 ):701-7
references.pmid: 8703169
references.citation: Atherosclerosis. 2014 Jun;234(2):295-302
references.pmid: 24721189
references.citation: Curr Neurol Neurosci Rep. 2013 Nov;13(11):391
references.pmid: 24046182
references.citation: Thromb Haemost. 2007 Mar;97(3):425-34
references.pmid: 17334510
references.citation: Blood Rev. 2007 May;21(3):157-71
references.pmid: 17118501
references.citation: Neurosurgery. 2001 Nov;49(5):1084-9; discussion 1089-90
references.pmid: 11846901
references.citation: J Neurotrauma. 2014 Oct 1;31(19):1672-5
references.pmid: 24605991
references.citation: J Surg Res. 2013 Oct;184(2):981-8
references.pmid: 23622728
references.citation: Br J Neurosurg. 2014 Aug 25;:1-5
references.pmid: 25153987
references.citation: J Neurotrauma. 2007 Feb;24(2):315-28
references.pmid: 17375996
references.citation: Blood. 2013 Sep 12;122(11):1873-80
references.pmid: 23798713
references.citation: Thromb Res. 2014 Sep;134(3):652-8
references.pmid: 25086657
references.citation: Acta Neurochir (Wien). 2008 Feb;150(2):165-75; discussion 175
references.pmid: 18166989
references.citation: J Trauma Acute Care Surg. 2014 Feb;76(2):255-6; discussion 262-3
references.pmid: 24458031
references.citation: Surgery. 2012 Jun;151(6):831-6
references.pmid: 22316436
references.citation: J Neurol Neurosurg Psychiatry. 1975 Jun;38(6):567-71
references.pmid: 1151424
references.citation: J Neurotrauma. 2013 Jul 15;30(14):1232-42
references.pmid: 23360174
references.citation: J Trauma. 2009 Aug;67(2):266-75; discussion 275-6
references.pmid: 19667878
references.citation: J Trauma Acute Care Surg. 2012 Aug;73(2):401-6; discussion 406-7
references.pmid: 22846946
references.citation: J Neurotrauma. 2007 Nov;24(11):1699-706
references.pmid: 18001200
references.citation: J Trauma. 2008 Mar;64(3):698-704
references.pmid: 18332810
references.citation: Thromb Res. 2012 May;129 Suppl 2:S27-9
references.pmid: 22424856
references.citation: Surg Neurol. 2009 Nov;72(5):481-9; discussion 489
references.pmid: 19328537
references.citation: Ann Surg. 2010 Apr;251(4):604-14
references.pmid: 20224372
references.citation: Injury. 2007 Dec;38(12):1382-91
references.pmid: 18048037
references.citation: J Neurotrauma. 2014 Dec 1;31(23):1927-33
references.pmid: 24956150
references.citation: J Trauma. 2009 Apr;66(4):994-9; discussion 999-1001
references.pmid: 19359905
references.citation: Neurocrit Care. 2013 Apr;18(2):201-8
references.pmid: 22847397
references.citation: J Trauma. 2010 Apr;68(4):881-5
references.pmid: 20386283
references.citation: Neurosurgery. 2012 Jun;70(6):1334-45
references.pmid: 22307074
references.citation: J Trauma Acute Care Surg. 2014 Nov;77(5):692-700
references.pmid: 25494419
references.citation: Cell Mol Life Sci. 2011 Aug;68(16):2667-88
references.pmid: 21560073
references.citation: J Trauma Acute Care Surg. 2013 May;74(5):1231-7; discussion 1237-8
references.pmid: 23609272
references.citation: J Neurotrauma. 2007 Jan;24(1):174-80
references.pmid: 17263681
references.citation: Int J Gynaecol Obstet. 2008 Sep;102(3):271-4
references.pmid: 18550060