Timing of relapse as a key indicator of steroid-sparing requirements in childhood idiopathic nephrotic syndrome.

BACKGROUND: Managing children with frequent relapses or steroid-dependent nephrotic syndrome poses challenges due to recurrent relapses necessitating prolonged steroid exposure, thus increasing susceptibility to long-term complications. Identifying those at risk of poor response to steroid therapy may be helpful to guide timely intervention with steroid-sparing agents. This study aimed to identify factors associated with steroid-sparing agent needs in children with frequent relapses or steroid-dependent nephrotic syndrome.

METHODS: A retrospective multicenter cohort study was conducted by reviewing the medical records of children with idiopathic nephrotic syndrome treated between 2006 and 2023. Cox proportional regression analyzed prognostic factors for steroid-sparing agent requirements in children with frequent relapses or steroid-dependent nephrotic syndrome. The time-to-event analysis utilizing the Kaplan-Meier estimate examined the proportion of children needing steroid-sparing agents after diagnosis.

RESULTS: Medical records of 121 children (85 males) diagnosed with idiopathic nephrotic syndrome at a median age of 4.5 years (range 1.3-12.8) were reviewed over a median follow-up of 3.7 years (range 1.0-15.0). Time to subsequent relapse post-frequent relapses or steroid-dependent nephrotic syndrome diagnosis (at 3-month threshold) emerged as the sole significant predictor of steroid-sparing agent requirement, adjusted hazard ratio (aHR) = 2.26, 95% confidence interval (CI) 1.26-4.05. Kaplan-Meier analysis indicated that an earlier first relapse (< 3 months) led to earlier steroid-sparing agent requirement (log-rank p = 0.005). Children who relapsed within 3 months post-frequent relapses or steroid-dependent nephrotic syndrome diagnosis exhibited a higher frequency of relapses, a greater incidence of steroid-related adverse events, and were more likely to develop steroid dependency.

CONCLUSIONS: Early subsequent relapse following diagnosis of frequent relapses or steroid-dependent nephrotic syndrome was linked to earlier requirement of steroid-sparing agent therapy. Further prospective research is necessary to confirm this observation.