Background: Since 1989 we have been promoting an Italian Registry of patients with APA (IR-APA), and we report here the analysis on 319 cases (80 males and 239 females, aged from 2 to 76 years, median 31 years) from 22 institutions.
Methods: A two-page questionnaire was prepared, divided into 4 parts: 1. personal data, 2. associated conditions, 3. biology (for the diagnosis of APA), 4. history of thromboembolism, haemorrhage and pregnancy. Every information was entered into a computerized registry.
Results: The IR-APA included 207 cases of idiopathic APA and 112 cases of APA secondary to SLE. Seventy-one out 207 (34.3%) and 47 out of 112 (42%) cases experienced arterial and/or venous thrombosis, respectively (not significant). Among patients with a thrombotic history, venous thrombosis were experienced by 60.5% vs 57.4%, arterial thrombosis by 26.7% vs 31.9%. Venous thrombosis of the legs and arterial thrombosis of the cerebral vessels were the most common types of thrombosis in both groups. Thrombocytopenia was present in 27.7% of idiopathic APA vs 22.4% of secondary APA (not significant). Four patients experienced major haemorrhagic events.
Conclusions: This retrospective study shows that the prevalence of thrombosis and thrombocytopenia in patients with idiopathic APA is similar to that observed in patients with APA secondary to SLE.