RESUMO
OBJECTIVE: Studies in adults with SLE have evidenced increase of homocysteine related, mainly, to thromboembolic events. The aim of our study was to evaluate plasma homocysteine concentration in children with systemic lupus erythematosus (SLE) and its correlation with renal involvement, serum and erythrocyte folate, vitamin B12, antiphospholipid antibodies, estimated creatinine clearance and dyslipidemia. METHODS: Thirty-two children (29 females) with SLE and 32 healthy controls (29 females) matched for age and sex were included in the study. The mean age of patients and controls was 14.2 years (range from 10 to 18 years). Only one patient presented one thrombotic event. Plasma homocysteine, erythrocyte and serum folate, vitamin B12, lipid profile, antiphospholipid antibodies and estimated creatinine clearance were evaluated. Raised homocysteine concentration was defined as equal or more than 12.9 mol/L. RESULTS: Raised homocysteine concentration was detected in 15 (46.9%) children with SLE with an important statistical difference in relation to control group (p < 0.001). A positive correlation was found between plasma homocysteine concentration and renal involvement (odds ratio 11.1 [95% CI 1.50-82.24], p = 0.01) based on the presence of renal biopsy, abnormalities of urine sediment and/or serum creatinine. However, when we performed the estimated creatinine clearance the correlation with homocysteine concentration was not positive. We did not observe abnormalities in serum and erythrocyte folate and vitamin B12 in our patients. However, they presented significant higher concentrations of TC total cholesterol (p = 0.005) and of LDL low-density lipoprotein (p = 0.02) than controls. CONCLUSION: Elevated plasma homocysteine concentration is frequent in children with SLE. We believe that these results may signalize to the possibility of complications in our patients later in life. Further long-term and prospective studies are needed in order to determine the real role of the homocysteine concentration as a risk factor in children.