ANTIPHOSPHOLIPID ANTIBODIES IN PEDIATRIC SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective. Antiphospholipid antibodies (aPLs) have been extensively st udied in adults with systemic lupus erythematosus (SLE) and have been associated with arterial and venous thrombosis, thrombocytopenia, neur ologic disorders, and recurrent fetal loss. In contrast, very little i s known about the frequency and clinical significance of aPLs in pedia tric SLE. This study was designed to determine the frequency of aPLs i n pediatric SLE and the temporally associated clinical manifestations. Design. We studied 29 consecutive patients with onset of SLE in child hood seen in the Pediatric Rheumatology Clinic at the University of Pi ttsburgh, Children's Hospital, between 1985 and 1992. We defined aPL a s the presence of a lupus anticoagulant (LAG), immunoglobulin G or imm unoglobulin M anticardiolipin antibodies (aCLs), or a biologic false-p ositive serologic test for syphilis determined by a VDRL test. Clinica l manifestations were temporally correlated to the presence of aPLs if they occurred within 6 months. Results. Overall, 19 (65%) of 29 child ren with SLE had one of the three laboratory abnormalities defining aP L. LAC was detected in 16 (62%) of 26, aCL in 18 (66%) of 27, and fals e-positive VDRL test results in 11 (39%) of 28. Twenty-five of the 29 patients had all three tests performed. In 10 patients, all three test s were abnormal. The presence of thrombosis in 7 patients (4 venous, 2 arterial, and 1 both) was associated with a positive aPL, specificall y aCL. The presence of an aPL, was significantly associated with anti- double-stranded DNA antibodies, but not with neuropsychiatric manifest ations or with thrombocytopenia. The presence of an aCL was significan tly associated with hemolytic anemia. A prolonged prothrombin time, in the setting of an LAC (all with a prolonged activated partial thrombo plastin time), was associated with life-threatening disease in 6 of 15 patients. Conclusion. Sixty-five percent of 29 consecutive pediatric patients with SLE had evidence of aPL. The presence of aPL, specifical ly aCL, was significantly associated with thrombotic events. The prese nce of a prolonged prothrombin time in the setting of an LAC may be a marker of more serious disease in pediatric SLE.