#1093 Remission rates and long-term outcomes of relapsed idiopathic nephrotic syndrome children treated with cyclophosphamide vs. cyclosporin A

Abstract

Abstract Background and Aims Approximately seventy percent of nephrotic syndrome (NS) children experience relapse episodes which are classified as frequently-relapsing nephrotic syndrome (FRNS), steroid-dependent nephrotic syndrome (SDNS), or steroid-resistant nephrotic syndrome (SRNS). In such cases, immunosuppressive drugs are combined to reduce the steroid side effects and prolong the remission period. However, the benefit of immunosuppressants and their side effects should be balanced. Objectives This study aimed to determine the remission rates and long-term outcomes of FRNS, SDNS, and SRNS children treated with cyclophosphamide vs. cyclosporin A (Cy A). Methods A retrospective review of medical records of children (aged < 15 years) with relapsed idiopathic nephrotic syndrome at Prince of Songkla University Hospital, southern Thailand during 2010-2021 was conducted. Demographic data, treatment responses, and adverse events were recorded. The remission rates, incidences of infection and acute kidney injury (AKI) in FRNS/SDNS and SRNS were compared between oral cyclophosphamide and Cy A treatments. Results There were 148 relapsed NS children, 102 (68.9%) boys, with a median age of 4.6 (IQR 2.5-8.4) years. FRNS, SDNS, and SRNS accounted for 37 (25.0%), 50 (33.8%), and 61 (41.2%) children, respectively. The cyclophosphamide treatment group (N = 135) had significantly higher remission rates in FRNS/SDNS than SRNS (63/85 (74.1%) vs. 11/50 (22.0%), P < 0.001), while the difference in remission rates in the Cy A treatment group (N = 53) was not statistically significant between FRNS/SDNS and SRNS (14/20 (70.0%) vs. 18/33 (54.5%), P = 0.265). Patients who had the Cy A treatment had significantly higher proportions of infections and AKI than children in the cyclophosphamide treatment group (20/53 (37.7%) vs 10/95 (10.5%), P < 0.001 and 21/53 (39.6%) vs 9/95 (9.5%), P < 0.001, respectively). Of the 148 children, at a median follow-up time of 8.7 (IQR 5.2–12.2) years, 21 (14.2%) and 9 (6.1%) children had developed chronic kidney disease (CKD) stage III or end-stage kidney disease (ESKD), respectively. The mean duration from CKD stage III to ESKD was 5.0+5.5 months. Conclusions Seventy percent of FRNS/SDNS children achieved remission with either Cy A or cyclophosphamide, but the SRNS children achieved remission proportionately better with Cy A than cyclophosphamide. However, the Cy A-treated children had higher proportions of infections and AKI than the cyclophosphamide treatment group. Overall, one-fifth of the relapsed childhood NS children developed CKD.