Vitamin E (VE) is a lipid-soluble, chain-breaking antioxidant agent that ameliorates a variety of diseases mediated by excessive production of oxygen free radicals. There is evidence that VE has a beneficial effect on progressive renal injury in experimental animals. Therefore, we studied the effect of VE supplementation to children with renal disease and persistent proteinuria.

In a prospective,open-label trial, we administered VE, 200 IU twice a day by mouth, to 17 patients, age 7-24 yr. The children were divided into two groups: Group A, steroid-resistant nephrotic syndrome (SRNS) and Group B, miscellaneous renal diseases. Group A comprised 10 patients (7M, 3F), mean age 12.5±1.2 yr, while Group B contained 7 children (5M, 2F), mean age 15±2 yr. Among the patients in Group B, 3 had HSP nephritis, 2 urinary tract anomalies, 1 IgA nephropathy,and 1 reflux nephropathy. Proteinuria was determined by measuring the protein:creatinine ratio (mg/mg) in an early morning specimen of urine, prior to and after VE treatment. Serum creatinine was also measured before and after administration of VE. The duration of VE treatment was defined as the period during which no other therapy was introduced and the estimated GFR did not change more than 20% from baseline.

In Group A, the duration of VE treatment was 2.3±0.6versus 4.1±0.7 months in Group B. There was a reduction in proteinuria in both groups of patients. Thus, in Group A, 9 out of 10 patients showed a decrease in proteinuria from 11.1±6.2 to 4.5±1.3(P<0.01). Although proteinuria declined in 5 out of 7 children in Group B, the reduction from 1.6±0.5 to 1.4±0.4 was not significant(P=0.38). Serum albumin and cholesterol concentrations were unchanged by VE treatment of patients in either Group A or B.

We have demonstrated that short-term oral administration of VE to patients with kidney disease leads to a 60% reduction in urinary protein excretion. This effect is more pronounced in children with SRNS compared to other kidney diseases. These findings suggest that; (1) oxygen free radicals contribute more to progressive renal injury in SRNS than in other kidney disorders; and(2) antioxidant therapy may be a useful adjunct in treating children with SRNS.