Pre-dialysis chronic kidney disease in children: results of a nationwide survey in Japan

Background. Chronic kidney disease (CKD) in children is a progressive and intractable condition that may severely impair the child's growth, development and quality of life. Epidemiological information on pediatric CKD, particularly in Asians, is scant. Methods. We conducted a nationwide, population-based survey of Japanese children aged 3 months to 15 years with pre-dialysis CKD to examine the prevalence of pediatric CKD in Japan. CKD was classified according to newly established criteria derived from reference serum creatinine levels in Japanese children. Surveys were sent to 1190 institutions across Japan to report on cases of pediatric CKD managed as of 1 April 2010. Results. A total of 925 institutions (77.7%) responded. Information on 447 children was collected. When subdivided according to our diagnostic criteria, 70.5% of children had stage 3 CKD, 23.9% stage 4 and 5.6% stage 5. The estimated prevalence of Japanese children with CKD was 2.98 cases/100 000 children. Of 407 CKD cases with non-glomerular disease, 278 (68.3%) had congenital anomalies of the kidney and urinary tract (CAKUT). The newly established criteria showed good validity compared with existing criteria, including the abbreviated Schwartz equation. Conclusions. Findings from the first nationwide survey of predialysis CKD in Asian children indicate that the prevalence of stage 3-5 CKD in children in Japan aged 3 months to 15 years is 2.98 cases/100 000 children. Most children with CKD presented with non-glomerular disease, most frequently CAKUT. Improved management of CAKUT, including renoprotective treatment and urological intervention, is required.