CHILDHOOD-ONSET SYSTEMIC LUPUS-ERYTHEMATOSUS - ANTIPHOSPHOLIPID ANTIBODIES IN 37 PATIENTS AND THEIR 1ST-DEGREE RELATIVES

Objective. Antiphospholipid antibodies (aPL) are noted with increased frequency in patients with systemic lupus erythematosus (SLE). The mai n manifestations found to be associated with aPL are arterial and veno us thrombotic events, thrombocytopenia, and recurrent pregnancy loss. This study is an attempt to define the incidence of aPL in patients wi th childhood-onset SLE and in their relatives and to correlate their p resence with clinical manifestations, and especially, to evaluate the risk of thrombosis in aPL-positive subjects. Methodology. We studied 3 7 unrelated patients and 107 of their first-degree relatives. VDRL, Ig G and IgM anticardiolipin, and IgG antiphosphatidylethanolamine antibo dies were studied in all probands during periods of clinical remission and in first-degree relatives at the time of interview. Lupus anticoa gulant had only been studied in probands during an SLE flare-up. Resul ts. Thirty-eight percent of probands and 19% of relatives were positiv e for at least one aPL, with little overlap between the different aPL studied. -No aPL-negative proband developed thrombosis. Two of the aPL -positive probands had thrombotic events before testing, and a third o ne showed thrombosis after testing. Only two probands had high levels of IgG aCL and showed thrombosis. The occurrence of aPL positivity in relatives was not always related to its presence in probands. None of the aPL-positive relatives had hadthrombosis, but recurrent fetal loss was noted in one aPL-positive mother with SLE. Although there was a h igh frequency of SLE, SLE-like disease, auto-immune disorders or posit ive serological findings for lupus in first-degree relatives, many of these relativew did not test positive for aPL. Conclusion. The high le vels of IgG aCL may be considered a risk factor for thrombosis. Findin gs in relatives suggest a multifactorial origin for autoimmune disease and antibody production.