Weight loss reduces anti-ADAMTS13 autoantibodies and improves inflammatory and coagulative parameters in obese patients.

Obese patients have been described at increased risk of thrombotic thrombocytopenic purpura, a disease caused by anti-ADAMTS13 autoantibodies. ADAMTS13 has a structure homology with the adipokine thrombospondin-1. We previously demonstrated an increased presence of anti-ADAMTS13 antibodies in obese patients. We aimed to study the changes induced by weight loss after bariatric surgery on some inflammatory and coagulative parameters and their link with anti-ADAMTS13 autoantibodies. We studied 100 obese patients before and after weight loss induced by bariatric surgery and 79 lean volunteers as controls. We measured anthropometric, metabolic and inflammatory parameters, thrombospondin-1, ADAMTS13 activity, anti-ADAMTS13 autoantibodies, Von Willebrand factor. At baseline, 13 % of patients was positive for anti-ADAMTS13 autoantibodies, while all controls were negative. Thrombospondin-1 levels were higher in obese subjects with than without antibodies, with a positive correlation between the two parameters. In multiple logistic regression analysis only thrombospondin-1 levels predicted positivity for anti-ADAMTS13 antibodies. After weight loss both anti-ADAMTS13 antibodies and thrombospondin-1 reduced significantly. Weight loss in obesity improves the inflammatory and coagulative profile, and in particular anti-ADAMTS13 autoantibodies, ADAMTS13 activity and thrombospondin-1.

Discrepant ratios of arterial versus venous thrombosis in hemophilia A as compared with hemophilia B.

The occurrence of thrombosis in patients with congenital bleeding disorders represents an exceptional event. Hemophilia A and hemophilia B patients have been showed to present both arterial and venous thrombosis (85 cases of arterial thrombosis and 34 cases of venous thrombosis). The great majority of arterial thrombosis are myocardial infarction or other acute coronary syndromes, whereas the majority of venous thrombosis are deep vein thrombosis and/or pulmonary embolisms. However there are discrepancies in the proportion of arterial and venous thrombosis seen in hemophilia A versus hemophilia B. The ratio of arterial versus venous thrombosis in hemophilia A is 3.72 whereas that for hemophilia B is 1.12. This indicates that arterial thrombosis is more frequent in hemophilia A as compared to hemophilia B and the opposite is true for venous thrombosis. The potential significance of this discrepancy is discussed.

Congenital Thrombophilia and Intracardiac Thrombosis: Probably an Underdiagnosed Event.

BACKGROUND: To investigate the number of patients with congenital thrombophilia who presented an intracardiac thrombosis. METHODS: Personal files were reevaluated together with a time-unlimited search of the literature. RESULTS: Twenty-five patients with intracardiac thrombosis and congenital thrombophilia have been gathered from the literature including the two personal cases. The distribution observed in thrombophilia patients is similar for left side or right side heart (9 vs 11 cases). The left ventricle and the right ventricle were involved in six or five instances, respectively. In one case, both ventricles were involved. On the contrary, the left atrium was involved in three cases whereas the right atrium was affected in six cases. In the remaining cases, more than one heart chamber was involved. CONCLUSIONS: In "normal" subjects, left side thromboses are predominant once catheter-associated thrombi are excluded. The reason of this discrepancy lies in the greater prothrombotic effect exercised by congenital thrombophilia on venous thrombosis compared to arterial thrombosis. The relative high prevalence of cardiac thrombosis seen in patients with antithrombin and protein C deficiencies indicated that a cardiac evaluation should be carried out in all patients with these two defects.

Recombinant FVIIa concentrate-associated thrombotic events in congenital bleeding disorders other than hemophilias.

Recombinant FVIIa concentrate has been originally used in the treatment of hemophilia patients with inhibitors. Recently, its use has been expanded to a variety of off-label indications. Thrombosis is the most important side effect. This may occur especially in off-label use but also in hemophiliacs with inhibitors. The present study investigated the occurrence of thrombosis in congenital bleeding disorders other than hemophilias as gathered from personal files and from the literature. Fifteen patients (seven FVII deficiency, one fibrinogen defect, four FXI deficiency, one von Willebrand disease, and two Glanzmann's Thrombasthenia) have been evaluated. Thrombosis was arterial in eight instances, venous in six, whereas in one case the type of thrombosis was unspecified. In eight cases, associated risk factors were present. Two patients with FXI deficiency had inhibitors. Dosage was variable. There was at least one fatality but in five cases evolution was not reported. The remaining patients recovered with variable sequels.