Does low protein concentration of tissue-type plasminogen activator predict a low risk of spontaneous deep vein thrombosis?
Many reports have demonstrated an abnormal fibrinolysis in a subset of patients with deep vein thrombosis. We have studied systemic global fibrinolytic activity and protein concentrations of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) in plasma of 25 young patients with a previous instance of spontaneous deep vein thrombosis documented by phlebography and in 50 healthy controls. The two populations were comparable with respect to a number of base-line variables (age, height, weight, etc.), while the patients had significantly lower fibrinolytic activity (p < 0.02), and significantly higher protein concentrations of t-PA (p < 0.0001) and PAI-1 (p < 0.0006). We used probit scale plots to identify the consequence of different cut-off points to separate patients from controls. Reasonable separation could be obtained for t-PA with a cut-off point of 5.2 ng/ml and for PAI-1 18 ng/ml. The sensitivity and specificity for these cut-off points were for t-PA 73% (95% confidence interval 63%-84%) and for PAI-1 67% (confidence interval 55%-77%). The negative predictive value with a cut-off point t-PA concentration of 5.2 ng/ml was 85% (95% confidence interval 70%-94%). We observed a significantly negative association between concentration of t-PA and fibrinolytic activity (rs = -0.47; p < 0.005) and also between PAI-1 and fibrinolytic activity (rs = -0.78; p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
Gram
J
J
Department of Clinical Biochemistry, Ribe County Hospital in Esbjerg, Denmark.
Sidelmann
J
J
Jespersen
J
J
D000328:Adult; D003289:Convalescence; D005260:Female; D005342:Fibrinolysis; D006801:Humans; D008297:Male; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis*; D011237:Predictive Value of Tests; D012306:Risk; D012680:Sensitivity and Specificity; D013924:Thrombophlebitis / Q000097:blood / Q000453:epidemiology*; D010959:Tissue Plasminogen Activator / Q000032:analysis*
D017395:Plasminogen Activator Inhibitor 1; D010959:Tissue Plasminogen Activator