Background and objectives: Although the safety and efficacy of cyclosporine in children with frequently relapsing nephrotic syndrome (FRNS) have been confirmed, no prospective follow-up data on relapse after cyclosporine have appeared. This study is a prospective follow-up trial after 2-year treatment with cyclosporine to investigate cyclosporine dependency after its discontinuation.
Design, setting, participants, & measurements: Participants who had undergone 2-year protocol treatment with microemulsified cyclosporine for FRNS between January 2000 and December 2005 were followed for an additional 2 years. The primary end point was relapse-free survival after the complete discontinuation of cyclosporine, and the secondary end point was regression-free survival (time to regression to FRNS).
Results: After exclusion of 7 patients who showed regression to FRNS during the 2-year treatment period, 49 children (median age, 6.5 years) were followed, and classified as children without (n=32; group A) and with (n=17; group B) relapse during the initial cyclosporine treatment. Overall, relapse-free survival probability at 24 months after cyclosporine discontinuation was 15.3% and regression to FRNS-free survival probability was 40.8%. By group, the probability of relapse-free survival was significantly higher in group A (17.9%) than in group B (8.3%) (P<0.001).
Conclusions: Children with FRNS who receive cyclosporine are at high risk of relapse after discontinuation, particularly those who experience relapse during cyclosporine treatment.