Immunological and clinical differences between juvenile and adult onset of systemic lupus erythematosus

INTRODUCTION: Systemic lupus erythematosus (SLE) in children usually follows a more severe course than in adults, but sometimes in the previous studies reported there are many confounding factors. OBJECTIVE: To analyse the immunological and clinical characteristics of SLE juvenile onset and SLE adult onset. METHODS: We studied 179 patients with SLE, 49 patients were aged 6-18 yrs at onset of disease. Anti-dsDNA antibodies were detected by radioimmunoassay and antibodies to extractable nuclear antigens (ENA): anti-nRNP, anti-Sm, anti-Ro/SS-A and anti-La/SS-B antibodies by ELISA, counterimmuno-electrophoresis and immunoblotting. RESULTS: Juvenile-onset SLE shows a higher frequency of cutaneous vasculitis (44.8% vs 27.6%; P < 0.05), seizures (18.3% vs 7.6%; P < 0.05) nephropathy (67.3% vs 48.4%; P < 0.025), and discoid lupus erythematosus (26.5% vs 13.8%; P < 0.05). The incidence of articular manifestations is lower than in adults (85.7% vs 96.1%; P < 0.025). No significant differences were found between the two groups in relation with the prevalence of antinuclear antibodies. CONCLUSIONS: Juvenile-onset SLE has more frequent neurological and renal manifestations than adult-onset SLE, but immunological markers are similar in both groups. These features suggest the most severe clinical manifestations in the juvenile-onset SLE group are not related with the presence of studied antibodies by different methods.