Objectives: To asses risk factors for a first thrombotic event in antiphospholipid antibody (aPL) positive carriers and to evaluate the efficacy of prophylactic treatments.
Methods: Recruitment criteria were: age 18-65 years, no history of thrombosis, positivity for lupus anticoagulant and/or IgG and/or IgM anticardiolipin antibody (aCL) on two or more occasions at least 6 weeks apart. Patients with antiphospholipid syndrome related pregnancy morbidity were included. Demographic, laboratory and clinical parameters were collected at enrollment and at the time of the thrombotic event.
Results: We retrospectively analyzed 370 patients/subjects (344 women and 26 men; mean age: 34 years ± 9.9 SD, range 18-65) for a mean follow-up of 59.3 months ± 45.5 SD (range 5-239). Thirty patients (8.1%, annual incidence rate 1.64%) developed a first thrombotic event (60% arterial and 40% venous) during the follow-up. Hypertension and medium/high levels of IgG aCL were identified by multivariate logistic regression analysis as independent risk factors for thrombosis. Thromboprophylaxis during high risk and long-term periods was significantly protective.
Conclusions: Our findings suggest that hypertension and/or medium/high titres of IgG aCL are risk factors for a first thrombotic event in asymptomatic aPL carriers and that primary prophylaxis is protective.