Timing and predictive factors of developing chronic kidney disease in childhood-onset idiopathic nephrotic syndrome: an Asian experience

INTRODUCTION: Idiopathic nephrotic syndrome (INS) is the commonest type of nephrotic syndrome in children, and a majority of cases have favourable outcomes. A small proportion of INS cases progress to chronic kidney disease (CKD). We investigated the time to CKD and predictive risk factors associated with progression of CKD in these children.

METHODS: A retrospective review of medical records was done to investigate the demographic variables, and biochemical and histological changes in children with INS aged 12 months to 18 years between 2001 and 2016 at Hospital Universiti Sains Malaysia. The median renal survival time for progression to CKD stage III or higher was determined using survival curve analysis. Multiple Cox regression analysis was used to identify predictive factors for CKD.

RESULTS: The total number of participants was 112 (boys: n = 71; girls: n = 41) and a majority had steroid-sensitive INS. Only about 10% of INS progressed to CKD Stage III or higher, with an overall median renal survival time of 19 years. Median renal survival time in steroid-resistant nephrotic syndrome (SRNS) was 13 years. Focal segmental glomerulosclerosis was predominant in SRNS. The predictors of progression to CKD were steroid resistance (adjusted hazard ratio [HR] [95% confidence interval (CI)] 23.8 [2.8-200.9]) and the presence of hypertension at presentation (adjusted HR [95% CI] 8.1 [1.2-55.7]).

CONCLUSION: The median renal survival time in our study was comparable to other studies. SRNS and the presence of hypertension at presentation were the main predictors for developing CKD in our population.