Long-term effects of levamisole treatment in childhood nephrotic syndrome

The effects of levamisole treatment on long-term outcome were evaluated in a retrospective study of frequently-relapsing (FRNS, n=15), steroid-dependent (SDNS, n=13), and steroid-resistant (SRNS, n=6) nephrotic syndrome in 34 children (21 boys, 13 girls, mean age 5.0+/-3.4 years) during a 60-month follow-up period. The definition of frequent relapses was greater than or equal to4 relapses per year. The current relapse was treated with prednisolone 60 mg/m(2) per day for 4 weeks, then with 40 mg/m(2) every other day for 4 weeks, after which the dose was tapered by 10 mg weekly. From the beginning of the 5th week, levamisole was introduced at a dose of 2 mg/kg per day. The duration of levamisole treatment was 17+/-7 months. Before starting levamisole treatment the mean level of proteinuria was 2.17+/-1.34 g/day and the relapse rate was 4.41/year. By the end of levamisole therapy, proteinuria had fallen to 0.142+/-0.211 g/day and the relapse rate to 0.41/year. No relapse occurred in 23 of the 34 patients during levamisole treatment. In the 24-month follow-up period after the discontinuation of levamisole, 28 children remained in total remission, while 6 had relapses. The cumulative steroid dose before levamisole therapy was 7,564.4+/-3,497.1 mg/year and following the introduction of levamisole 1,472.9+/-1,729.9 mg/year (P<0.0001). We observed reversible neutropenia in 5 patients, but no other side effects were seen. Our findings suggest that in FRNS and SDNS levamisole significantly reduces both the relapse rate and the cumulative steroid dose; therefore, it could be recommended for these patients. In SRNS patients it has also some benefit because proteinuria and the cumulative steroid dose could be reduced significantly.