Paediatric systemic lupus erythematosus: prognostic impact of antiphospholipid antibodies

Objectives. The aim of our study was to investigate the prognostic impact of aPL in paediatric onset systemic lupus erythematosus (p-SLE). Methods. This retrospective study included 56 patients with p-SLE. chi(2)-test, Fishers exact test, incidence rate ratio and Kaplan-Meier survival curves were used to compare aPL-positive and aPL-negative patients considering the value of SDI (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index for SLE) at the end of follow-up, the occurrence of thromboses, organ system involvements and need for immunosuppressive treatment in addition to corticosteroids. Results. Anti-cardiolipin antibodies and lupus anticoagulants were detected in 27 (49%) and 19 (35%) patients, respectively. These aPL were frequently transient or intermittent (10 and 15 cases, respectively), and only rarely persistent over time (five cases). The risk of thrombosis was significantly higher (odds ratio=6.42) and occurred earlier in the presence of aPL, especially if aPL were persistent (P < 0.05). The association between aPL and neurological, renal, haematological manifestations or need for immunosuppressive treatment was not statistically significant. After a mean follow-up of 7.2 yrs, 30 patients (54.5%) had an SDI score >= 1. The risk of damage (SDI >= 1) in aPL-positive patients was three times higher than in aPL-negative patients (P < 0.05). Four of the six fatal cases occurred in the aPL-positive group. Conclusions. The presence of aPL in p-SLE could represent not only a risk factor for thrombosis but also a poor prognostic factor overall.