THE RELATIONSHIP OF ANTIPHOSPHOLIPID ANTIBODIES TO THROMBOEMBOLIC EVENTS IN PEDIATRIC-PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS - A CROSS-SECTIONAL STUDY

The purpose of this study was to evaluate pediatric patients with syst emic lupus erythematosus (SLE) to determine I) the incidence of thromb osis, 2) the incidence of antiphospholipid antibodies, and 3) whether there is an association between the presence of antiphospholipid antib odies and thrombosis. We performed a cross-sectional cohort study in 5 9 consecutive SLE patients who had been managed at rheumatology clinic s in two pediatric hospitals. A history, questionnaire, and chart revi ew were completed by the study nurse blinded to laboratory results. On ly the thrombotic events that could be substantiated by review of radi ographic tests were accepted. The presence of antiphospholipid antibod ies was determined by prospective analysis for a lupus anticoagulant a nd anticardiolipin antibodies on two separate occasions at least 3 mo apart. Patients were considered to be positive if one or more tests we re positive on both occasions. Thirteen thrombotic events occurred in 10 of the 59 patients (17%). Fourteen patients (24%) were classified a s positive for lupus anticoagulant, and 19 patients (27%) were classif ied as positive for anticardiolipin antibodies. A significant relation ship between the presence of a lupus anticoagulant and a thrombotic ev ent was shown: odds ratio 28.7 (95% confidence interval 4.03-138.2, p < 0.001). A nonsignificant trend was seen for the presence of an antic ardiolipin antibody and a thrombotic event: odds ratio 2.12 (95% confi dence interval 0.71-22.8, p = 0.08). We conclude that in pediatric pat ients with SLE: 1) a significant proportion of patients have thromboti c events, 2) a significant proportion of patients have antiphospholipi d antibodies, and 3) there is a significant relationship between the p resence of a lupus anticoagulant and thrombotic events.