Thrombosis and thrombocytopenia in antiphospholipid syndrome (idiopathic and secondary to SLE): first report from the Italian Registry. Italian Registry of Antiphospholipid Antibodies (IR-APA).

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.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.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.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.