Effect of toxic shock syndrome toxin-1 on human hemostatic parameters

The effect of toxic-shock-syndrome-toxin-1 (TSST-1) on coagulation and platelet aggregation was studied in blood samples from human healthy volunteers. TSST-1 at 5 micrograms/ml does not modify the extrinsic or intrinsic coagulation pathways. However, thrombin clotting time (TCT) was significantly increased in the presence of TSST-1. Platelet aggregation was not directly affected by TSST-1 but the toxin strongly inhibited platelet aggregation induced either by epinephrine, adenosine diphosphate (ADP) or platelet activating factor (PAF), while having no effect on aggregation induced by thrombin, collagen or a calcium ionophore. The above results suggest that TSST-1 may bind to a transducer common for some aggregators or that it may induce some non-specific modification of platelet membrane.