Vitamin E treatment of focal segmental glomerulosclerosis: results of an open-label study
Experimental data indicate that excessive production of reactive oxygen molecules contributes to progressive renal injury and that treatment with antioxidants attenuates this damage. Therefore, we investigated whether vitamin E supplementation could ameliorate renal disease and reduce proteinuria in children with a variety of kidney disorders. Vitamin E, 200 IU twice daily, was administered orally to 11 children with focal segmental glomerulosclerosis (FSGS) (group A) and 9 patients with miscellaneous kidney diseases (group B) [Henoch-Schönlein purpura nephritis (n=3), urinary tract anomalies (n=2), non-specific immune complex glomerulonephritis (n=2), IgA nephropathy (n=1), and reflux nephropathy (n=1)]. The duration of vitamin E treatment, when no other therapy was introduced, was 2.9±0.4 months. Proteinuria was determined by measuring the protein:creatinine ratio (mg/mg) in an early morning urine specimen. In children with FSGS, administration of vitamin E lowered the protein:creatinine ratio in 10 of 11 patients from 9.7±5.1 to 4.1±1.1 (P<0.005). In contrast, among children with miscellaneous renal diseases, vitamin E had no beneficial impact on urinary protein excretion-protein:creatinine ratio 2.5±1.0 pre versus 2.4±1.2 post antioxidant. Vitamin E supplementation had no effect on glomerular filtration rate, serum albumin, or cholesterol concentration in either group of patients. These findings suggest that reactive oxygen molecules may play a more-prominent role in causing renal injury in patients with FSGS than in other kidney disorders. Antioxidant therapy may be a useful adjunct in the treatment of children with FSGS and proteinuria that is refractory to standard medical management.