Familial clustering of defective release of t-PA.
91 unrelated patients with idiopathic or familial deep vein thrombosis (DVT) and 72 (34 with DVT) relatives from 26 families were screened for hypofibrinolysis by measuring tissue plasminogen activator antigen (t-PA:Ag) after venous occlusion (VO) for 10 and 20 min and by measuring t-PA inhibitor activity (PAI) at rest. 21 healthy subjects served as controls. Defective release of t-PA:Ag was found in eight out of the 91 patients (9%). A partial family study of six of these eight patients was performed. This study included 10 family members with and 21 without DVT. A defective release of t-PA:Ag was found in 50% (5/10) of the family members with DVT, which is significantly more frequent than the 9% (8/91) prevalence in the unrelated patients (P less than 0.001). Furthermore, 24% (5/21) of asymptomatic members of these families also had defective release of t-PA:Ag. In the 18 families where the propositus had a normal level of t-PA:Ag, none of the 24 studied family members with DVT had defective release of t-PA:Ag. In contrast to the defective release of t-PA:Ag, increased basal level of PAI did not show familial clustering. In conclusion, low release of t-PA during VO shows familial clustering in a proportion of the cases.
Petäjä
J
J
Finnish Red Cross Blood Transfusion Service, Kivihaantie, Helsinki, Finland.
Rasi
V
V
Vahtera
E
E
Myllylä
G
G
D000328:Adult; D003250:Constriction; D005260:Female; D005342:Fibrinolysis / Q000502:physiology; D006801:Humans; D008297:Male; D010375:Pedigree; D015849:Plasminogen Inactivators / Q000097:blood; D015995:Prevalence; D013924:Thrombophlebitis / Q000097:blood / Q000235:genetics*; D010959:Tissue Plasminogen Activator / Q000097:blood*; D014680:Veins
D015849:Plasminogen Inactivators; D010959:Tissue Plasminogen Activator