Long-term, low-dose prednisolone therapy in frequently relapsing nephrotic syndrome.

The efficacy of daily administration of a small dose of prednisolone was examined in 21 patients with corticosteroid-responsive, frequently relapsing nephrotic syndrome (FRNS). After induction of remission of a third or subsequent relapse with a 6-week course of prednisolone (standard therapy with prednisolone, STP), this drug was continued in a single daily dose of 0.25 mg/kg body weight (low-dose prednisolone, LDP) for 18 months. Relapses occurring during this period were treated with STP, following which LDP therapy was resumed. The historical controls comprised 14 patients with FRNS in whom relapses were treated with STP and who were observed over a minimum period of 30 months. The two groups were comparable for age at the onset of nephrotic syndrome and sex. Twenty patients completed LDP therapy, during which 12 had no relapse, 6 had infrequent and 2 frequent relapses (1 patient became steroid dependent and was taken off LDP). Twelve patients were followed for 12-42 months after stoppage of LDP; during this period 7 had no relapse, 4 had infrequent relapses and 1 showed steroid dependence. The number of relapses during LDP therapy (0.5/patient per year) was significantly less (P less than 0.001) than in the preceding 12 months (3.62/patient per year), and continued to remain low during the following 12 months (0.6/patient per year). Whereas the frequency of relapses in the LDP group was similar to that in the historical control group in the 1st year of comparison, it was significantly less during LDP therapy (0.5/patient per year versus 2.25/patient per year). No side effects were observed in patients on the LDP regimen, at the end of which the height percentiles improved in 6 patients and remained unchanged in 14. Our observations indicate that long-term therapy with a small daily dose of prednisolone can significantly reduce the number of relapses in patients with FRNS, and that the beneficial effect may continue even after its stoppage.