A hypercoagulable state and an increased incidence of thromboembolic complications are reported in Cushing's syndrome. The hypercoagulable state is related to an increase in plasma clotting factors, especially Factor VIII and von Willebrand factor complex, and to an impairment of fibrinolytic capacity. Retrospective analysis of postoperative thromboembolic events in a large group of patients with Cushing's syndrome, including 75 patients (group 1) evaluated in the period from 1972-1981 not receiving anticoagulants, and 232 patients (group 2), evaluated in the period from 1982-2000. Patients of group 1 underwent routine hemostatic function, i.e. prothrombin time and activated partial thromboplastine time. Patients of group 2 underwent a thorough investigation as to hemostatic parameters and received prophylactic treatment with heparin and/or warfarin. Patients with Cushing's syndrome showed various abnormalities of hemostatic parameters. A significant correlation between activated partial thromboplastine time and urinary free cortisol was observed. During follow-up, 15 patients (20%; mean follow-up, 9.4 +/- 6.4 yr) of group 1 and 14 (6.0%; mean follow-up, 6.6 +/- 4.2 yr) of group 2 showed thromboembolic complications. Of these patients, eight of group 1 and one of group 2 died. Survival analysis demonstrated a significantly higher morbidity and mortality due to thromboembolic events in group 1, not receiving anticoagulant prevention, than in group 2, treated with anticoagulants in the perioperative period until cure of the disease and normalization of clotting parameters. Cushing's syndrome is associated with a hypercoagulable state. An adequate anticoagulant prophylaxis can reverse this prothrombotic state and avoid postoperative thromboembolic events.

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SummaryA deletion/insertion polymorphism (4G or 5G) in the promoter of the plasminogen activator inhibitor type 1 gene has been suggested to be involved in regulation of the synthesis of the inhibitor, the 4G allele being associated with enhanced gene expression. A relationship between 4G/5G polymorphism and PAI-1 levels was found in patients with cardiovascular and metabolic diseases, but not in healthy subjects. In the present work we studied the distribution of PAI-1 4G/5G geno-type and its relation to fibrinolytic capacity in 70 unrelated patients with deep vein thrombosis. Each patient was assayed before and after 20 min. Venous occlusion for euglobulin lysis time, t-PA antigen and activity, and PAI-1 antigen and activity. The prevalence of 5G homozygous carriers was significantly lower in patients than in controls (10% vs. 26%, p = 0.009). The 5G allele frequency was reduced, even though not significantly, in DVT patients compared to healthy subjects (0.40 vs. 0.51, respectively). In the patient group, the mean PAI-1 antigen and activity levels were significantly higher than among controls and related to the 4G/5G polymorphism. In patients with 4G/5G and 4G/4G genotype a significant correlation was found between PAI-1 levels and the global fibrinolytic activity as evaluated by euglobulin lysis time. The prevalence of a reduced fibrinolytic potential due to PAI-1 excess was 45.7% among DVT patients. Moreover, the prevalence of PAI-1 induced hypofibrinolysis was strongly related to PAI-1 polymorphism, since it was significantly lower in 5G homo-zygous patients (28.6%) than in both 4G/5G carriers (55.3%, p <0.001) and 4G homozygous patients (57.9%, p <0.001).In conclusion, in patients with deep vein thrombosis the 4G polymorphism of PAI-1 gene promoter may influence the expression of PAI-1 and it should be taken into consideration as a facilitating condition for pathological fibrinolysis together with other environmental and genetic factors. Whether this has any significance in regard to the pathogenesis of venous thrombosis remains to be proven.

SummaryFactors XII, XI, IX and VIII, plasminogen and alpha2-antiplasmin levels were found to be increased in a group of patients affected by Cushing’s syndrome. High activity of these coagulation factors could be due to their increased release and synthesis mediated by cortisol. A significant correlation between the main arterial pressure and either factor VIII antigen, ristocetin cofactor or factor XII activity was found. Moreover a similar correlation between factor XII activity and either factor VIII antigen or ristocetin cofactor was seen. In conclusion, the presence of a hypercoagulable state in Cushing’s syndrome seems confirmed. Synergic release of factor XII and factor VIII from endothelium could be due to high blood vessel tone secondary to hypercorticism. Finally, decreased fibrinolytic activity was suspected according to plasminogen and alpha2-antiplasmin increase.

Genetic and acquired factors may influence phenotypic expression of inherited thrombophilia. Hypofibrinolysis due to excess PAI-1 can be found in patients with deep vein thrombosis (DVT) and 4G/5G polymorphism of the PAI-1 gene may modulate the inhibitor's synthesis. In 149 patients with inherited thrombophilia, the possible thrombotic contribution of both 4G/5G polymorphism and PAI-1 plasma levels was evaluated. Sixty-seven patients with idiopathic DVT and 98 normal subjects were also studied. By comparison with controls, a significantly higher prevalence of 4G/4G genotype was seen in idiopathic DVT and in thrombophilia patients, although in this latter group the difference only remained significant in cases symptomatic for thrombosis (p = 0.01). The 4G/4G genotype was associated with a greater risk of thrombosis both in symptomatic thrombophilia patients (OR 2.85, 95% CI 1.26-6.46) and in idiopathic DVT patients (OR 3.1, 95% CI 1.26-7.59). The greater frequency of 4G allele in symptomatic thrombophilia patients with respect to controls was statistically significant (p = 0.04). Compared to healthy subjects, PAI-1:Ag levels were higher in symptomatic thrombophilia patients and related to the 4G/5G polymorphism, with significantly higher values in the 4G/4G carriers. In conclusion, PAI-1 4G/5G polymorphism may influence PAI-1 expression and thrombotic risk in patients with inherited thrombophilia.