A lifelong bleeding disorder associated with a deficiency of plasminogen activator inhibitor type 1.
A 36-year-old patient was investigated for a lifelong history of epistaxis and delayed bleeding after minor surgeries. Deficiencies or abnormalities of the coagulation system, of platelet function, or of factor XIII and alpha-2-antiplasmin were excluded. Consistently, however, over a period of 7 years, a high basal euglobulin fibrinolytic activity was observed that was characterized by a high tissue-type plasminogen activator (t-PA) activity, normal t-PA antigen, and undetectable plasminogen activator inhibitor type-1 (PAI-1) antigen and activity. The high specific activity of t-PA (640,000 IU/mg) and the minimal amounts of t-PA/PAI-1 complexes detected by fibrin zymography suggest that in this patient all t-PA was active. This is in striking contrast to normal plasma, where the majority of t-PA is complexed to PAI-1. Thus, in this patient, a severe deficiency of PAI-1 is associated with a delayed type bleeding tendency. Our observation underscores the importance of plasma PAI-1 for the stabilization of the hemostatic plug.
Diéval
J
J
Laboratory of Hematology, University Hospital, Amiens, France.
Nguyen
G
G
Gross
S
S
Delobel
J
J
Kruithof
E K
EK
D000328:Adult; D000941:Antigens / Q000378:metabolism; D001778:Blood Coagulation Disorders / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D015849:Plasminogen Inactivators / Q000276:immunology / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000276:immunology / Q000378:metabolism
D000941:Antigens; D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator