Assessment of fibrinolytic activity by measuring the lysis time of a tissue-factor-induced clot: a feasibility evaluation.
A clot lysis time assay in which a tissue factor-induced fibrin clot is lysed by exogenously added tissue plasminogen activator has been recently reported. We evaluated the feasibility of clot lysis time in a routine hemostasis laboratory, and its correlation with thrombin activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 levels and changes with aging in 185 healthy participants. Clot lysis time was assessed by monitoring changes in turbidity during clot formation and subsequent lysis using a computerized kinetic spectrophotometric microtiter plate. After preliminary experiments, 100 and 160 ng/mL tissue plasminogen activator concentrations were chosen for the study. Clot lysis time was calculated by a new mathematical analysis of the lysis curve based on discrete derivative. Clot lysis time, thrombin activatable fibrinolysis inhibitor, and plasminogen activator inhibitor-1 plasma levels showed a normal distribution. For both concentrations of tissue plasminogen activator, clot lysis time progressively increased with increase in age (P < .0001) and was significantly correlated with thrombin activatable fibrinolysis inhibitor antigen, thrombin activatable fibrinolysis inhibitor activity, and plasminogen activator inhibitor-1 antigen (at least P < .01). During linear regression analysis, thrombin activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 antigen were found to significantly influence clot lysis time (at least P < .01). Clot lysis time determination has a good laboratory performance. Our new method of calculation is independent of the time of reading and allows a more accurate and consistent detection of both short and prolonged lysis times. Our data suggest the feasibility of the use of this test in the work of routine hemostasis laboratory.
Cellai
Anna Paola
AP
Department of Heart and Vessels, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy. annapaolacellai@tiscali.it
Lami
Donatella
D
Magi
Alberto
A
Liotta
Agatina Alessandrello
AA
Rogolino
Angela
A
Antonucci
Emilia
E
Bandinelli
Brunella
B
Abbate
Rosanna
R
Prisco
Domenico
D
D000328:Adult; D000367:Age Factors; D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests / Q000379:methods*; D002122:Calcium Chloride / Q000494:pharmacology; D025901:Carboxypeptidase B2 / Q000097:blood; D005240:Feasibility Studies; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry; D010743:Phospholipids / Q000494:pharmacology; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D013925:Thromboplastin / Q000494:pharmacology*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000097:blood / Q000494:pharmacology; D055815:Young Adult
D010743:Phospholipids; D017395:Plasminogen Activator Inhibitor 1; C051321:SERPINE1 protein, human; D013925:Thromboplastin; D025901:Carboxypeptidase B2; D010959:Tissue Plasminogen Activator; D002122:Calcium Chloride