Platelet activation, coagulation activation and C-reactive protein in simultaneous samples from the vascular access and peripheral veins of haemodialysis patients J. A. MILBURN*, I. FORD † , K. CASSAR † , N. FLUCK ‡ , J. BRITTENDEN † INTRODUCTION Patients with established chronic kidney disease (ECKD) receiving haemodialysis (HD) therapy have a 20-fold higher risk of death compared with the gen- eral population (Cheung et al. 2004; Hage et al., 2009). The leading cause of death is cardiovascular disease, as a result of the development of acute ORIGINAL ARTICLE INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY *Department of Vascular Surgery, University of Aberdeen, Aberdeen Royal Infirmary, Aberdeen, UK † School of Medicine and Dentistry, University of Aberdeen, Aberdeen Royal Infirmary, Aberdeen, UK ‡ Renal Medicine, University of Aberdeen, Aberdeen Royal Infirmary, Aberdeen, UK Correspondence: James A. Milburn, Specialist Registrar, Vascular Unit, Ward 36, Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, UK. Tel.: +44 1224 552281; Fax: +44 1224 552553; E-mail: j.milburn@nhs.net doi:10.1111/j.1751-553X.2011.01356.x Received 27 February 2011; accepted for publication 11 May 2011 Keywords Haemodialysis, platelet activation, thrombosis, vascular access, veni- puncture SUMMARY Introduction: Most studies of haemodialysis (HD) patients compare venous blood samples from controls with samples from the vascular access (VA) of HD patients. We hypothesised that VA samples may be more prothrombotic compared with venous samples. Methods: Samples were taken simultaneously from the VA and the contralateral antecubital vein, from 26 patients immediately before HD. Platelet function was assessed by (1) flow cytometric measure- ment of P-selectin expression and fibrinogen binding (±ADP) and 2)Ultegra rapid platelet function assay. Plasma soluble P-selectin, von Willebrand factor antigen, high sensitivity C-reactive Protein (hs-CRP), thrombin-antithrombin III complex and D-dimer mea- sured by ELISA. Results: Thrombin receptor activating peptide-induced platelet aggregation (P < 0.001) and hs-CRP (P < 0.001) were higher in VA compared with venous samples. Unstimulated platelet fibrinogen binding (P = 0.016) and ADP-stimulated P-selectin expression (P = 0.008) were lower in VA compared with venous samples. The significant difference in hsCRP persisted when patients taking and not taking antiplatelet therapy were analysed separately, but plate- let activation remained significantly different only in the nonanti- platelet group. Conclusion: There are statistically significant differences between sampling sites, although samples from the VA do not appear to be more pro-thrombotic. Future studies comparing HD patients with controls should ensure uniformity of sampling sites to prevent inac- curate conclusions being drawn. 52 Ó 2011 Blackwell Publishing Ltd, Int. Jnl. Lab. Hem. 2012, 34, 52–58 International Journal of Laboratory Hematology The Official journal of the International Society for Laboratory Hematology