Background and objectives Poor linear growth is a frequent complication of CKD. This study evaluated the effect of kidney transplantation on age-related growth of linear body segments in pediatric renal transplant recipients who were enrolled from May 1998 until August 2013 in the CKD Growth and Development observational cohort study.Design, setting, participants, & measurements Linear growth (height, sitting height, arm and leg lengths) was prospectively investigated during 1639 annual visits in a cohort of 389 pediatric renal transplant recipients ages 2-18 years with a median follow-up of 3.4 years (interquartile range, 1.9-5.9 years). Linear mixed-effects models were used to assess age-related changes and predictors of linear body segments.Results During early childhood, patients showed lower mean SD scores (SDS) for height (21.7) and a markedly elevated sitting height index (ratio of sitting height to total body height) compared with healthy children (1.6 SDS), indicating disproportionate stunting (each P,0.001). After early childhood a sustained increase in standardized leg length and a constant decrease in standardized sitting height were noted (each P,0.001), resulting in significant catch-up growth and almost complete normalization of sitting height index by adult age (0.4 SDS; P,0.01 versus age 2-4 years). Time after transplantation, congenital renal disease, bone maturation, steroid exposure, degree of metabolic acidosis and anemia, intrauterine growth restriction, and parental height were significant predictors of linear body dimensions and body proportions (each P,0.05). ConclusionsChildren with ESRD present with disproportionate stunting. In pediatric renal transplant recipients, a sustained increase in standardized leg length and total body height is observed from preschool until adult age, resulting in restoration of body proportions in most patients. Reduction of steroid exposure and optimal metabolic control before and after transplantation are promising measures to further improve growth outcome.

Our findings demonstrate a marked improvement of growth and maturation in paediatric patients on RRT during the past 20 years.

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This study was designed to compare three urinary protein expert systems for profiling proteinuria in children with kidney diseases. Freshly voided urine specimens were collected from 61 children with glomerular diseases, 19 children with tubular diseases and 25 healthy children aged 3-16 years. The urinary protein expert systems were: (1) albumin/total protein ratio (APR), (2) alpha-1-microglobulin/alpha-1-microglobulin + albumin algorithm (AAA), and (3) the complex urine protein expert system (UPES, PROTIS) algorithm. APR correctly identified glomerular proteinuria in 47/61 children, tubular proteinuria in 16/19 children and normal proteinuria in 23/25 healthy children. AAA correctly identified glomerular proteinuria in 61/61 children and tubular proteinuria in 18/19 children, and 25/25 healthy children were characterized as having no abnormal proteinuria. AAA was not influenced by the stage of chronic kidney disease. UPES differentiated the type of proteinuria in children with glomerular diseases into glomerular (50/61 patients) and mixed glomerulo-tubular (6/61 patients). Tubular proteinuria was identified in 16/19 patients and described as mixed glomerulo-tubular proteinuria in 3/19 patients. Mixed glomerulo-tubular proteinuria was found only in children with chronic kidney disease stages 2-5 of glomerular and tubular diseases. In conclusion, the AAA and UPES had the highest accuracy levels.

Children with congenital CKD had the highest rate of prematurity, a significantly lower birth weight, length, head circumference and Apgar score than newborns with hereditary or acquired CKD. Irrespective of the aetiology of CKD, all of the children had a significantly higher rate of SGA and prematurity than the reference population. We conclude that both SGA and prematurity predispose for advanced renal disease in childhood and that fetal kidney disease impairs fetal growth.