ANTITHROMBIN-III DEFICIENCY AND RECURRENT VENOUS THROMBOSIS

Antithrombin III is the main physiologic inhibitor of blood clot forma tion. Deficiences in AT-III, usually due to genetic causes, are manife sted by venous thrombosis which is often recurrent or occurs unexpecte dly at a young age. AT-III deficiencies are usually quantitative, rare ly qualitative. Whereas management is well-standardized in patients wi th inherited AT-III deficiencies, more uncertainty surrounds the corre ct approach to acquired forms in which the decision to use anticoagula nt drugs is based on the clinical setting and on the results of hemost asis tests. In patients with AT-III deficiency, an essential step is t o remove risk factors for thrombosis, including smoking and oral contr aceptive.