Tantalum stents induce expression of GMP140 and GP53 on platelets after contact in an in vitro model.
Endovascular implantation of stents has become increasingly important to reduce acute complications and restenosis after percutaneous transluminal coronary angioplasty (PTCA). Nevertheless, the risk of stent related thrombosis still appears to be a limitation in this therapeutic approach. As platelets play a major role in thrombus formation, we examined platelets in an in vitro model by flow cytometry to assess the expression of activation-dependent epitopes caused by shear stress and contact to artificial surfaces of stents. Tantalum wire stents (n = 12) were placed in one of two parallel silicon tubing systems. Both systems were filled with citrated platelet-rich plasma (PRP) of healthy and drug-free volunteers. After recalcification, aliquots of PRP were drawn via a three-way faucet over a course of 10 min. For flow cytometric analysis monoclonal antibodies CD41a, CD42b, CD62p and CD63 were applied. Within 2 min after onset, the expression of CD62p (GMP140) and CD63 (GP53) increased in the tubing system with the stent. Over the course of 10 min, platelet activation progressively increased (CD62p p < 0.05 vs. control system without stent; CD63 p < 0.005 vs. control). Antigens CD41 a and CD42b did not show significant changes in both systems. Artificial surfaces and shear forces of stent meshes may contribute to the activation of platelets, thereby promoting the thrombotic potential. As an utmost sensitive diagnostic tool, flow cytometry may attribute to further improvement of material and design of stents.
Gutensohn
K
K
Dept of Transfusion Medicine and Transplantation Immunology, University Hospital Eppendorf, Hamburg, Germany.
Beythien
C
C
Bau
J
J
Meinertz
T
T
Kühnl
P
P
D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation; D016824:Antigens, Human Platelet / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D012307:Risk Factors; D015607:Stents; D013635:Tantalum / Q000009:adverse effects*; D013927:Thrombosis / Q000097:blood*
D016824:Antigens, Human Platelet; D013635:Tantalum