A predictive model of progressive chronic kidney disease in idiopathic nephrotic syndrome.

BACKGROUND

There are limited data on the risk factors for chronic kidney disease (CKD) in children with idiopathic nephrotic syndrome (INS). This retrospective cohort study aimed to develop a predictive model for CKD progression in children with INS.

METHODS

Between 1970 and 2012, a total of 294 patients with INS were followed up. The primary outcome was progression to CKD stage 3 or higher. A predictive model was developed using a Cox proportional hazards model. A score was calculated using b-coefficients and summing up points assigned to each significant variable. Prognostic score was grouped into categories: low risk, medium risk, and high risk.

RESULTS

Median follow-up was 6.9 years. Median renal survival was 26.1 years and probability of CKD stage 3 or higher was 8% in 10 years. Multivariate analysis showed that the most accurate model included initial age, hematuria, and steroid resistance. Accuracy was high with a c-statistic of 0.95 (95% confidence interval [CI] 0.91-0.99), 0.92 (95% CI 0.88-0.96), and 0.92 (95% CI 0.87-0.97) at 2, 5, and 10 years of follow-up respectively. By survival analysis, 10-year renal survival was 100% for the low-risk and 95% for the medium-risk group, while 40% of high-risk patients would exhibit CKD stage 3 or higher (P < 0.001).

CONCLUSIONS

Our predictive model of CKD may contribute to the early identification of a subgroup of INS patients at a high risk of renal dysfunction.