It has been experimentally shown that endotoxin induces a marked increase in the levels
of a fast-acting inhibitor of plasminogen activator (PAI). The plasma PAI activity
and tissuetype plasminogen activator (t-PA) concentrations were measured in 61 patients
with human septicaemia and results were compared with those observed in healthy controls.
There was a markedly significant increase of PAI in plasma and platelet extracts of
patients with septicaemia as compared to controls (p <0.0001). No correlation between
PAI and endotoxin concentration was observed. Fibrin autography of plasma samples
confirmed that activator inhibition was associated with the formation of an enzyme-inhibitor
complex. t-PA activity was similar in patients and controls, whereas t-PA Ag showed
a significant increase in patients (p <0.0001). A significant inverse correlation
between t-PA activity and PAI was observed (p <0.05). PAI activity was higher in patients
with positive blood cultures (p <0.0001) and gram-negative septicaemia (p <0.0001).
There was also a significant increase of PAI levels in patients with disseminated
intravascular coagulation (DIC) as compared with patients without DIC (p <0.001).
We conclude that there is a marked increase of PAI in patients with sepsis. Increased
PAI activity may contribute to the pathogenesis of DIC associated with septicaemia.
Keywords
Plasminogen activator inhibitor - Bacterial infection - Disseminated intravascular
coagulation
