Modification of activation-dependent platelet antigens CD62p and CD63 during haemodialysis.

In particular, activated platelets are thought to be involved in the pathophysiology of thrombotic occlusions of vessels. In this study, we evaluated activation-dependent changes in platelet antigens during extracorporeal haemodialysis treatment. Flow cytometry was used in combination with monoclonal antibodies that bind to platelet glycoproteins CD62p (GMP-140) and CD63 (GP53). Maximum peaks of mean channel fluorescence intensity (MCFI) were reached after 60 min in 20/26 procedures in CD62p (P < 0.005) and in 15/25 treatments in CD63 (p < 0.002), respectively. An initial peak of CD62p and CD63 fluorescence expression could be detected in 21/25 and 23/25 treatments, respectively (CD62p within 15, CD63 within 30 min), indicating the early onset of activation. The structural antigen CD41a MCFI slightly decreased over time in all treatments, while CD42b expression did not change. From these results we conclude that haemodialysis contributes to platelet activation and secondary hypercoagulability. Analysis of platelet glycoproteins by flow cytometry may provide clinical information on patients at a higher risk for thrombosis and may help in further improvement of haemodialysis equipment.