Inherited thrombophilic risk factors in a large cohort of individuals referred to Italian thrombophilia centers: distinct roles in different clinical settings.

BACKGROUND AND OBJECTIVES Despite inherited thrombophilic risk factors being strongly associated with vein thrombosis, decisions on whether to screen subjects for these factors vary in different clinical settings. DESIGN AND METHODS We calculated the prevalence of inherited thrombophilic risk factors in a large cohort of patients (n=1,238) with different clinical manifestations of vein thromboembolism. In the present cohort, screening for inherited thrombophilia was worthwhile among patients who developed vein thrombosis of the leg or cerebral vein thrombosis. Carriers of FV Leiden or FII A(20210) mutation more frequently had had deep vein thrombosis of the leg (OR: 4.35; 95% CI: 3.39-5.60), superficial vein thrombosis (OR: 3.34; 95% CI: 2.06-5.41), or cerebral vein thrombosis (OR: 2.77; 95% CI: 1.10-6.96). RESULTS The screening program appeared to have a limited relevance in patients with isolated pulmonary embolism (OR: 2.13; 95% CI: 1.28-3.54), or mesenteric vein thrombosis (OR: 2.05; 95% CI: 1.22-3.44). INTERPRETATION AND CONCLUSIONS The lack of association with inherited thrombophilia does not justify routine screening of patients with thrombosis of the upper extremities or with retinal vein thrombosis.