In vitro comparison study of CD63 and CD62P expression after contacting leukocyte filters

CD63 and CD62P have been recognized as platelet activation markers. This st udy investigated the secretion of these antigens to compare the platelet ac tivation between a newly developed stainless steel leukocyte filter (SSLF) and 7 polyester or polyurethane commercially available leukocyte filters. F low cytometry demonstrated that the SSLF initiated significantly smaller ef fects in terms of mean fluorescence intensity of CD63 (p < 0.03) and of the amount of CD62P expressing platelets (p < 0.002) compared to the polyureth ane filters. However, there was no statistical difference between the SSLF and polyester filters. The result of this study suggests that the SSLF caus ed less platelet activation than the polyurethane filters and has biocompat ible characteristics comparable to the currently available polyester filter s. Stainless steel was selected because of its physicochemical conductivity . With these results, further evaluation of the SSLF will be continued in a n attempt to develop an active immunomodulator using this unique characteri stic.