Long-term effects of immunosuppressants in steroid-dependent nephrotic syndrome

In order to elucidate long-term effects of immunosuppressants, we studied 60 children with steroid-dependent nephrotic syndrome who were treated with three immunosuppressants: cyclophosphamide (n=34), chlorambucil (n=11), and cyclosporin A (n=15). Each relapse before and after the administration of immunosuppressants was evaluated longitudinally in terms of the relapse-free period and the maintenance dose of prednisolone required. The median follow-up period after immunosuppressants was 5.2 years (range 0.5-20.3 years). The relapse-free period was significantly longer in all groups after the initiation of immunosuppressants. However, the relapse-free period after subsequent relapses as compared with the previous relapse was longer in the cyclophosphamide group, similar in the chlorambucil group, and shorter in the cyclosporin A group. The prednisolone dosage at relapse was reduced in subsequent relapses after cyclophosphamide and chlorambucil treatment, but tended to be higher in later relapses after the initiation of cyclosporin A. These findings suggest that the effects of cyclophosphamide are long lasting, while those of chlorambucil and cyclosporin A are of short duration. Children who relapse after cyclosporin A treatment may experience a worse relapsing course.