Predictive factors of chronic kidney disease in primary focal segmental glomerulosclerosis

Renal histological features of focal segmental glomerulosclerosis (FSGS) are found in 75% of pediatric patients with steroid-resistant nephrotic syndrome. In order to evaluate the predictive factors of chronic kidney disease (CKD), we retrospectively reviewed the records of 110 children with biopsy-proven FSGS admitted between 1972 and 2004. Renal survival was analyzed by the Kaplan-Meier method and Cox's regression model. Two multivariate models were developed: (1) from the onset of symptoms to the occurrence of CKD and (2) from the time of renal biopsy to CKD. Mean follow-up time was 10 years [standard deviation ((SD) 5.5], and 24 patients (21.8%) progressed to CKD. At baseline, after adjustment three variables remained as independent predictors of CKD: age > 6.5 years (RR=3.3, 95% CI=1.3-7.8), creatinine > 1 mg/dl (RR=2.5, 95% CI=0.97-6.5), and non-response to steroids (RR=7.3, 95% CI=2.7-19.7). In a model with continuous variables only age and non-response to steroids were associated with CKD. At the time of renal biopsy, after adjustment two variables remained as independent predictors of CKD: hematuria (RR=3.0, 95% CI=1.2-7.3) and creatinine > 0.8 mg/dl (RR=4.3, 95% CI=1.7-10.6). In a model with continuous variables four factors predicted CKD: age, creatinine, hematuria, and percentage of global sclerosis.