The presence of antiphospholipid (aPL) antibodies and antiphospholipid syndrome (APS) was researched in 57 children and adolescents with systemic lupus erythematosus (SLE). The frequency of aPL antibodies was 75.4% (anticardiolipin 70.2% and lupus anticoagulant 29.1%). The positivity for these antibodies fluctuated during the course of the disease. No association was found between aPL antibodies and clinical or laboratory manifestations or the autoantibodies studied, nor with the activity or gravity of the SLE. APS was diagnosed in 14% of the cases (eight patients), on average three years after the diagnosis of SLE. Four patients had arterial thrombosis (stroke, three; transient ischaemic attack, one; amaurosis fugax, two; renal, one), one presented with deep vein thrombosis (DVT) and three had involvement of small calibre vessels (osteonecrosis, two; transverse myelitis, one). Recurrences were observed in three of the eight cases (37.5%), with a mean interval of 13 months between the events. The presence of APS was associated with haemolytic anaemia, leukopenia, thrombocytopenia, coagulation abnormalities, ischaemic cerebrovascular accidents, amaurosis fugax, osteonecrosis and interstitial pneumonitis. A negative association was observed between APS and the presence of anti-Ro antibodies.
