title: Prothrombotic changes in platelet, endothelial and coagulation function following hemodialysis.
abstract: OBJECTIVE
  Patients on hemodialysis (HD) have an increased risk of thrombotic events, including myocardial infarction and vascular access thrombosis. The study hypothesis is that a single session of dialysis leads to platelet, endothelial and coagulation activation. Our aim is to determine the effect of a single HD session on prothrombotic vascular biomarkers before and after a single session of hemodialysis.
  
  
  METHODS
  Blood samples were taken from the vascular access of 55 patients immediately before and after a hemodialysis session. Platelet function was assessed by (1) flow cytometric measurement of P-selectin expression and fibrinogen binding +/- ADP stimulation, (2) Ultegra rapid platelet function assay (RPFA) using the agonists thrombin receptor activating peptide (TRAP) and arachidonic acid (AA), (3) soluble P-selectin, and (4) soluble CD40L. Coagulation (thrombin-antithrombin III [TAT] and D-dimer), endothelial von Willebrand factor (vWF) and high sensitivity C-Reactive protein (hsCRP) were assessed by ELISA.
  
  
  RESULTS
  Unfractionated heparin was given to all patients during dialysis and 30 patients (55%) were on antiplatelet agents. Post-hemodialysis there were significant increases in unstimulated platelet P-selectin (p=.037), stimulated P-selectin (p<.001), soluble P-selectin (p<.001) and soluble CD40L (p=.036). Stimulated platelet fibrinogen binding was increased post-hemodialysis (p<.001) but unstimulated fibrinogen binding was unchanged. TRAP- (p<.001] and AA-(p=.009) stimulated aggregation were reduced post-hemodialysis. There were increases post-hemodialysis in TAT (p<.001), D-dimer (p<.001), vWF (p<.001) and hsCRP (p=.011).
  
  
  CONCLUSIONS
  This study has shown that despite heparin therapy, a single session of HD induced increases in platelet, endothelial, and coagulation activation. More effective medical strategies to reduce the prothrombotic state of patients on hemodialysis should be investigated.
authors: Department of Vascular Surgery, University of Aberdeen and Aberdeen Royal Infirmary, Aberdeen, Scotland, UK. j.milburn@nhs.net
authors: James A
authors: JA
authors: Milburn
authors: Kevin
authors: K
authors: Cassar
authors: Isobel
authors: I
authors: Ford
authors: Nicholas
authors: N
authors: Fluck
authors: Julie
authors: J
authors: Brittenden
mesh_terms: D000328:Adult; D000368:Aged; D001777:Blood Coagulation / Q000502:physiology; D001792:Blood Platelets / Q000502:physiology*; D042783:Endothelial Cells / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D006439:Hemodynamics; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015539:Platelet Activation / Q000502:physiology; D006435:Renal Dialysis