Objective: Antiphospholipid antibody (APL) is a particularly important laboratory diagnostic criterion for antiphospholipid syndrome (APS). The significances of positive APL in childhood are seldom reported nor fully understood. The purpose of this study was to analyze 13 cases with positive APL seen in our hospital and to study the relationship between the positive rates of APL and various clinical diseases especially systemic lupus erythematosus (SLE) in order to improve the clinical diagnoses and treatment level of APS in children.
Methods: The clinical data collected from 2000 to 2002 of 13 hospitalized children with positive APL were retrospectively evaluated. Enzyme linked immunosorbent assay (ELISA) and indirect immunofluorescence technique were used respectively to detect APL and antineutrophil cytoplasmic autoantibodies (ANCA) of sera from those children. Other various indexes were also detected according to different characteristics of different diseases.
Results: Eight cases had SLE; 2 had acute post-streptococcal infections. The other 3 cases did not show any evidences of primary diseases; they probably had primary APS. SLE was the most common primary diseases to cause development of APL and the cases with SLE showed more severe cutaneous vasculitis than SLE patients who were negative for APL. There was no significant relationship between the positive rates of APL and that of ANCA. Eight APL positive cases complicated with thrombocytopenia and bleeding were treated with high dosage of immunoglobulin [400 mg/(kg.d), for 3 - 5 d] intravenously; the clinical conditions of these cases were ameliorated soon. While the 5 cases who had thrombotic vasculitis and thromboembolism were treated with anticoagulant and antithrombotic therapy with low molecular weight heparin [50 - 100 U/(kg.d)], which led to good clinical effects.
Conclusions: The clinical manifestations of children positive for APL were somehow different from those of adults. Positive APL itself may be nonspecific, it can occur from different causes of diseases. APL detection may be useful to suggest anticoagulant and/or antithrombosis therapy. Treatments for APS should be variable according to different causes and severity of diseases, in the cases of thrombocytopenia and bleeding, high dose intravenous immunoglobulin should be given as soon as possible, while in the cases of thrombotic vasculitis and thromboembolism, anticoagulant and antithrombotic therapy should be given soon.