Title: Streptokinase-induced platelet-aggregation - prevalence and mechanism
Streptokinase-induced platelet aggregation. Prevalence and mechanism
Authors: Vaughan, De ×
Vanhoutte, E
Declerck, Paul
Collen, Desire #
Issue Date: Jul-1991
Publisher: Amer heart assoc
Series Title: Circulation vol:84 issue:1 pages:84-91
Abstract: BACKGROUND. Streptokinase (SK) is a bacteria-derived protein and one of the plasminogen activators that is currently available for therapeutic use. Exposure to SK induces synthesis of specific antibodies that may initiate platelet aggregation and paradoxical clot propagation during treatment. METHODS AND RESULTS. Using platelet-rich plasma (PRP), we found that SK (5,000 units/ml) but not urokinase (2,500 units/ml) or recombinant tissue-type plasminogen activator (2,500 units/ml) caused platelet aggregation in PRP from 14 of 100 normal volunteers. In 13 consecutive patients treated with SK for acute myocardial infarction, SK-mediated platelet aggregation was induced in five patients within 1 week after treatment. SK-mediated platelet aggregation was associated with significantly increased titers of both anti-SK antibodies and SK-neutralizing activity in plasma; it was partially inhibited by aspirin (1 mM) and by aprotinin (500 kallikrein inhibitor units/ml) and completely inhibited by tranexamic acid (1 mM) and by prostaglandin E1 (9 microM). Addition of SK (1,000 or 5,000 units/ml) induce a statistically significant dose-dependent thromboxane B2 release in mixtures of PRP with plasma from subjects with SK-induced aggregation but not in samples of PRP mixed with plasma from nonresponders; addition of recombinant tissue-type plasminogen activator (1 or 50 micrograms/ml) did not induce thromboxane B2 release. Mixing experiments with PRP and immunoglobulin G from reactive and nonreactive donors revealed that SK-induced aggregation requires the presence of anti-SK antibodies. When 125I-SK (50 nM) was used, platelets preincubated with plasminogen (0.5 microM) bound 9,500 +/- 600 (mean +/- SEM, n = 6) molecules SK/platelet, which increased to 25,000 +/- 3,100 molecules/platelet after thrombin stimulation. Tranexamic acid (1 mM) blocked specific binding of SK to resting platelets. CONCLUSIONS. These data demonstrate that SK-induced platelet aggregation is initiated by the binding of anti-SK antibodies to the SK-plasminogen complex located on the platelet surface. SK-induced platelet activation may limit the therapeutic effectiveness of the drug, and in view of the high prevalence of aggregation in a normal population, prospective evaluation of the effects of platelet aggregation during treatment with SK is warranted.
ISSN: 0009-7322
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Laboratory for Pharmaceutical Biology (-)
Molecular and Vascular Biology
× corresponding author
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science