Homocysteine and lipid profile in children with Juvenile Idiopathic Arthritis

An increased concentration of plasma homocysteine (Hcy) has toxic effects on vascular endothelium. This seems to be a risk factor of cardiovascular disease, premature stroke and venous thrombosis. The risk is higher in coincidence with other factors like chronic diseases and familiar hypercholesterolemia. The aim of our study was to evaluate plasma Hcy concentration in patients with juvenile idiopathic arthritis (JIA) and its correlation with methotrexate (MTX) therapy, serum folate and B12 vitamin, and hyperlipidemia.

Fifty-one patients (37 females; mean age 11.3 years, range 2.3-17 years) with JIA and 52 healthy controls (42 females; mean age 12.5 years; range 3-18 years) were included in the study. Thirty-two patients were using weekly MTX (mean doses: 0.1-1 mg/kg). For statistical analysis both JIA and control groups were distributed in three subgroups according to age (3 - 7, 8 - 12 and 13 - 18 years). The laboratory investigation included measurement of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), plasma Hcy, serum folate, vitamin B12, triglycerides, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). For data analysis, we considered raised Hcy values >or= 12.56 micromol/L, which corresponds to the 90th percentile observed in the control group.

The mean plasma Hcy concentration was 9.3 +/- 3.16 micromol/L in JIA patients and 8.9 +/- 2.42 micromol/L in healthy controls (p = 0.615). Higher concentration of Hcy was observed in the subgroup of 13 - 18 years (patients and controls, p < 0.001). We did not find correlation between MTX use and plasma Hcy concentration. With regard to vitamin B12 concentration, we detected normal values in both patients and controls while serum folate concentration was higher in patients (p < 0.001). With regard to the lipidogram, lower concentration of HDL was found in patients (p = 0.007) and higher levels of VLDL (p = 0.014) and triglycerides (p = 0.001) were observed in controls. We did not observe correlation among plasma Hcy concentration, clinical findings, ESR and CRP.

JIA patients do not present significant increased concentration of Hcy despite the use of MTX, probably due to the folate supplementation. The mild abnormalities in the lipidogram may reflect a current concern with diet and health.