A16: Long-term follow-up of 36 Pediatric Antiphospholipid Syndrome Patients: A Retrospective Study.

BACKGROUND/PURPOSE: Antiphospholipid syndrome (APS) is a multisystem autoimmune disease characterized by arterial and/or venous thrombosis and persistent presence of antiphospholipid antibodies. Long term follow-up studies in children are still scarce. The aim of this study was to evaluate clinical data and long-term outcome of patients with confirmed antiphospholipid syndrome in childhood.

METHODS: Between 1993 and 2013, 36 patients with confirmed pediatric antiphospholipid syndrome (22 female; aged 8 months-18 years, mean 9 years) were followed at the Pediatric Rheumatology Unit of the University Hospital of USP-RP. Clinical data and long-term outcome of these patients were reviewed retrospectively.

RESULTS: The median follow-up period was 8.5 years (0.6-20 years), fourteen (38.8%) had underlying autoimmune diseases (30% systemic lupus erytematosous, 5% Behcet's disease and 2.5% systemic juvenile idiopathic arthritis). Venous and arterial thrombosis on the first episode occurred in 14 (38%) and 22 (61%) patients, respectively. Ischemic stroke was the most frequent thrombotic event (50%). Three patients had thrombosis in two different sites on the first episode (inferior vena cava and cerebral sinus vein; lower extremities deep vein thrombosis and pulmonary thromboembolism; portal vein and jugular vein thrombosis). The most frequent associated nonthrombotic clinical manifestations were hematologic manifestations (27%), hypertension (22%), and valvulopaties, identified in 10/27 echocardiograms performed (37%), including one case of Libmann-Sachs endocarditis. The frequency of antiphospholipid antibodies identified were: IgG anticardiolipin in 24/35 (68%) patients, IgM anticardiolipin in 21/35 (60%), IgG anti-beta(2)-glycoprotein I in 6/31 (19%), IgM anti-beta(2)-glycoprotein I in 7/31(22%), and lupus anticoagulant in 17/35 (48%). Six patients were positive for all antiphospholipid antibodies investigated. During the follow-up period new thrombotic events occurred in 9 patients (25%), with catastrophic antiphospholipid syndrome in one of these patients. One patient had two new events (jugular vein thrombosis and pulmonary thromboembolism). Major hemorrhagic events, including intracranial hemorrhage and minor hemorrhagic events, including epistaxis, hematomas and hypermenorrhea occurred in 47% of the patients during the use of oral anticoagulants.

CONCLUSION: Despite of prophylaxis with anticoagulants, new thrombotic events occurred in 25% of the patients and reaching the ideal prothrombin time to prevent thrombotic episodes was the major challenge, as nearly half of the patients had hemorrhagic events. Studies are necessary to identify ideal parameters for treating and monitoring children with antiphospholipid syndrome.