The Relationship Of PAI-1/TAFI With Deep Venous Thrombosis And D-dimer、MMP-9and Venous Obstruction As Risk Factors For Postthrombosis Syndrome

Part ⅠThe relationship of PAI-1/TAFI with deep venous thrombosisObjective Active Plasminogen Activator Inhibitor-1(PAI-1) and Thrombin Activatable Fibrinolysis Inhibitor (TAFI) are important elements of fibrinolytic system, both of them can regulate thrombolysis process, and decrease the activity of fibrinolytic system. Although the decrease of fibrinolysis is an independent risk factor of venous thrombosis, the relationship of PAI-1and TAFI with deep venous thrombosis (DVT) is not clear. Our research aim to study the association of these two biomarkers and DVT, include the serum levels of Active Plasminogen Activator Inhibitor-1antigen and activity (PAI-1:Ag, PAI-1:Ac), Thrombin Activatable Fibrinolysis Inhibitor antigen and activity (TAFI:Ag, TAFI:Ac), and the interaction between PAI-1and TAFI, we also analyzed their diagnotic value.Methods We enrolled eighty inpatients with lower limbs deep venous thrombosis (LDVT) and forty healthy controls come from Physical examination center. We use Enzyme-Linked Immuno Sorbent Assay (ELISA) to measure serum levels of Active Plasminogen Activator Inhibitor-1antigen (PAI-1:Ag) and Thrombin Activatable Fibrinolysis Inhibitor antigen (TAFI:Ag), chromogenic assay to measure serum levels of Active Plasminogen Activator Inhibitor-1antigen (PAI-1:Ac) and Thrombin Activatable Fibrinolysis Inhibitor antigen (TAFI:Ac). Statistical analysis were performed using SPSS(Statistical Product and Service Solutions)13.0software. chi-square test、Student t-test and Mann-Whitney test were used for categorical variables、continuous variables and skewness distributed variables. Relationships between variables were assessed using Spearman correlation. Multiple comparisons were performed using One-way Anova or Kruskal-Wallis test. The association between risk factors and development of deep venous thrombosis were analyzed by univariate and multivariate logistic regression assay. Receiver operating characteristic curve analysis were used to evaluate diagnostic values of PAI-1:Ag、 PAI-1:Ac、TAFI:Agand TAFI:Ac.Results The PAI-l:Ag serum level statistically increased in DVT patients compared to healthy controls(45.64[22.79-56.31]ng/ml vs28.79[13.96-42.52]ng/ml,P=0.003). PAI-1:Ac serum level statistically increased in DVT patients (0.72[0.36-0.98] vs0.60[0.28-0.87] AU/ml, P=0.015).The serum level of TAFI:Ag increased in DVT patients(106.15±25.14vs96.35±28.13%, P=0.324), but have no statistic differences. The TAFI:Ac serum level significantly increased in DVT patients (32.69±8.73vs16.15±6.24μg/ml,P=0.006). Univariate and multivariate logistic regression assay showed the serum levels of PAI-l:Ag and PAI-1:Ac are independent risk factors of DVT. Spearman correlation assay observed a positive correlation between PAI-l:Ag and PAI-1:Ac serum levels (r=0.75, P<0.05), serum levels of TAFI:Ag and TAFI:Ac were positively correlated (r-0.60, P<0.05), there were no correlations between PAI-1and TAFI in healthy controls, in contrast, serum levels of PAI-1:Ag and TAFI:Ac in DVT patients were positively correlated (r=0.42, P<0.05). Using receiver operating characteristics assay we got areas under the ROC curve with95%confidence interval of PAI-1:Ag at0.68[0.56-0.77],PAI-1:Ac at0.82[0.74-0.85],we defined the cut off value of32.47ng/ml for PAI-1:Ag with sensitivity of70%and specificity of55%, the cut off value of0.63AU/ml for PAI-1:Ac with sensitivity of73%and specificity of84%.Conclusion Elevated PAI-1:Ag and PAI-1:Ac serum levels are associated with higher risks of DVT. PAI-1:Ac could be used as a better diagnotic predictor for DVT than PAI-1:Ag. Part IIThe relationship of D-dimer、MMP-9and venous obstruction with Postthrombosis SyndromeObjective Postthrombotic syndrome (PTS) is a severe long-term complication of Lower-limb deep vein thrombosis (LDVT), but few data are available on the risk factors for PTS. We aim to investigate the relationship of time-course of D-dimer, Matrix metalloproteinase-9(MMP-9), venous obstruction and PTS development.Methods We enrolled fifty patients with lower limbs deep venous thrombosis (LDVT) which were treated with anticoagulant therapy, with an avergae age of60.8±12.3years. Serum levels of D-dimer (Immunoturbidimetric Assays, STA Liatest), MMP-9(Enzyme-Linked Immuno Sorbent Assay, ELISA) were measured on day of diagnosis (Dayl), Day7, Day30and Day90. Compression ultrasound examination of whole leg was conducted on Dayl and Day7, Day30, and Day90to grade the venous obstruction according to our laboratory-made rating scale, every patient developed PTS has a score that considered thrombosis extent and occlusion degree. Villalta score was evaluated at Day30, Day90, and Day180for all individuals. Statistical analysis were performed using SPSS(Statistical Product and Service Solutions)13.0software. Relationships between variables were assessed using Pearson correlation, Comparisons between groups were using chi-square test or student t-test as needed, multiple comparisons for variables among groups were using Bonferroni’s correction. The association between D-dimer、MMP-9、venous obstruction score and risks of PTS were analyzed by univarate and multivarate logistic regression analysis.Results At Day90,9patients developed PTS (Villalta score≥5), At Day180,11patients had PTS. Patients with PTS compared with patients without PTS, the serum levels of D-dimer have no differences at any time point and there were no correlations between D-dimer levels and Villalta score. The MMP-9levels were significant higher in patients with PTS at Day90, Pearson correlation analyze showed MMP-9levels at Day90were correlated with Villalta score at Day90(r=0.41, p=0.000), venous obstruction score of patients with PTS at Dayl, Day30were similar to those without PTS, but statistically higher at Day90. venous obstruction score at Day90was correlated with Villalta score at Day90and Day180(r=0.35, p=0.010; r=0.52, p=0.004, respectively). Univariate and multivariate regression assay indicated that venous obstruction after three months of DVT are independent risk factors for the development of PTS (OR=1.95, P=0.034), Conclusion Elevated venous obstruction score after three months is associated with the higher risk of PTS development in DVT patients, might be used as an predictor and to direct the prevention treatment. MMP-9serum level and venous thrombotic obstruction after three months are correlated with Villalta score, monitoring the serum level of MMP-9would be helpful for early detection of PTS patients.