Clinical characteristics and outcomes of children with stage 3–5 chronic kidney disease

The aim of this study was to report on the clinical characteristics and outcomes of Belgian children with chronic kidney disease (CKD). Between 2001 and 2005, we followed 143 new successive patients younger than 20 years of age with a glomerular filtration rate of <60 ml/min/1.73 m² prospectively in a Belgian department of pediatric nephrology. The incidence of diagnosed CKD was 11.9 per million child population (pmcp), and the incidence of renal replacement therapy was 6.2 pmcp. There were 67% patients in CKD stage 3, 19% in CKD stage 4 and 14% in CKD stage 5. Patients with congenital anomalies of the kidney and urinary tract (CAKUTs), hereditary diseases and glomerular diseases were diagnosed at a median age of 1, 2 and 10 years, respectively. CAKUTs were the main causes of CKD, accounting for 59% of all cases. After 3, 4 and 5 years of follow-up, 27, 31 and 38% of patients treated conservatively, respectively, reached end-stage renal failure (ESRF). The progression rate to ESRF was eightfold higher in patients with CKD stage 4 than in those with CKD stage 3. Among our patient group, hereditary diseases progressed more rapidly to ESRF than CAKUTs. Transplantation was performed preemptively in 22% of these children. Infections and cardiovascular diseases were the main causes of death.