The effect of various anticoagulant/antiplatelet mixtures on determination of plasminogen activator inhibitor, platelet proteins and hemostasis parameters.

Blood collected in different anticoagulant/antiplatelet agents (ETP, EDTA, citrate, citrate/citric acid pH 4.5 and CTAD) was compared with respect to determination of PAI-1 activity and PAI-1 antigen. beta TG and PF4 were analysed as markers of platelet release. Both the middle layer and the remaining layer of the plasma were studied. Moreover vWF:Ag, FVII:Ag, ECLT, t-PA:Ag, t-PA activity, APTT, VIII:C and VII:C were assayed in blood collected in citrate and CTAD. PAI-1 activity showed the same level in all citrate based anticoagulants and ETP and no increase was found in blood standing for 2 hours at room temperature. On the contrary quick handling was most important for determination of PAI-1 antigen. In tubes anticoagulated with citrate no significant increase was found if the sample was prepared within 1 hour. EDTA was not suitable as anticoagulant mixture. Tubes containing the antiplatelet mixture CTAD could be used for determination of PAI activity, PAI antigen, vWF:Ag, FVII:Ag, t-PA activity and APTT. For measurement of PAI-1 antigen quick handling of blood anticoagulated with antiplatelet mixtures are preferable, and plasma treated in that manner could also be used to assay some hemostasis parameters.