 Coagulation and thrombophilia factors All blood samples will be drawn under fasting conditions in the morning. Determinations of PT, APTT, fibrinogen, antithrombin, protein C, protein S, lupus anticoagulant, FVIII two-stage chromogenic assay and D-dimer will be carried out on an automatic coagulometer ACL Top 700, IL. VWF-antigen VWF:activity will be measured in plasma samples by chemiluminescence assays. VWF multimer VWFm pattern was measured as previously reported 10. FV Leiden R506Q and prothrombin G20210A genotyping of these polymorphisms was performed by using commercial kits based on PCR-RT-based method from EliTechGroup S.p.A., Torino, Italy on an automatic instrument Model 7300, Applied Biosystem, Foster City, CA, USA. 