Citation

Nekludov M, Mobarrez F, Gryth D, Bellander BM, Wallen HN. J. Neurotrauma 2014; 31(23): 1927-1933.

Affiliation

Karolinska Institute and University Hospital, Physiology and Pharmacology, section for Anesthesiology, Stockholm, Sweden ; michael.nekludov@karolinska.se.

Copyright

(Copyright © 2014, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2013.3168

PMID

24956150

Abstract

The potential pathophysiological role of circulating microparticles (MPs) has been recognized in various conditions such as cardiovascular and thrombotic diseases. Traumatic brain injury has a complex pathophysiology which involves coagulopathy and inflammation. We investigated endothelial-, platelet- and leukocyte-derived microparticles (EMPs, PMPs and LMPs, respectively) in 16 patients with severe isolated TBI. Arterial and cerebrovenous samples were taken repeatedly, during 1-72 hours after the injury. Subpopulations of MPs, exposing Tissue Factor (TF) and P-selectin, were also studied. MP counts in cerebrovenous samples, irrespective of cellular origin, were higher in TBI cases, compared to healthy controls (peak levels of EMPs were around 7 times higher, PMPs 1.4 times higher, LMPs 2 times higher, respectively; p<0.001 for all). MP counts declined sharply from high levels shortly after the trauma towards slightly elevated levels 72 hours later. EMPs and PMPs exposing TF, as well as PMPs exposing P-selectin, showed a transcranial gradient with higher concentration in cerebrovenous compared to arterial samples. In contrast, LMPs exposing TF were higher in arterial samples, suggesting accumulation of LMPs in the brain. We conclude that the pattern of circulating MPs is altered following TBI. PMPs exposing P-selectin and EMPs exposing TF seem to be generated in the injured brain, whereas LMPs exposing TF are accumulated. The pathophysiological significance of these changes in MP pattern in TBI should be further investigated. Including MPs exposing brain specific antigens in the assessment of brain injury would give further information of origin and likely give additional information of the size of the injury, as the MP phenotypes investigated in the present study are not brain-specific markers.

Language: en