Taihei Hayashi1, Shuko Tokuriki2, Takashi Okuno2, Genrei Ohta2, Aiko Igarashi2, Yusei Ohshima2. 1. Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan. thayashi@u-fukui.ac.jp. 2. Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, 23-3 Simoaizuki, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 9101193, Japan.
Abstract
BACKGROUND: The number of nephrons at birth is determined during fetal development and is modulated thereafter by postnatal podocyte injury. Hyperfiltration, caused by a reduced number of nephrons, is a risk factor for chronic kidney disease. It is therefore important to monitor the formation of nephrons. METHODS: Urine samples were collected from infants within 1-2 days of birth, with follow-up sampling for preterm infants at 37-39 weeks of corrected age. Urinary levels of podocalyxin (PCX), β2-microglobulin (β2MG), N-acetyl-ß-D-glucosaminidase (NAG), total protein (TP), microalbumin (mAlb) and creatinine were measured and the relationship between these markers evaluated. RESULTS: Seventy-nine neonates were enrolled in this study. Urinary levels of PCX at birth were higher than normal adult reference values, with levels increasing up to a gestational age of 36 weeks (p = 0.0242). At 37-39 weeks corrected age, urinary levels of PCX decreased to adult levels. The levels of PCX in the urine at birth were not correlated to urinary levels of β2MG, NAG, TP and mAlb. CONCLUSIONS: An increased urinary level of PCX may be a marker of both active nephron formation and podocyte injury sustained at birth. As such, changes in urinary levels of PCX are likely to reflect adaptation of renal function to the extra-uterine environment.
BACKGROUND: The number of nephrons at birth is determined during fetal development and is modulated thereafter by postnatal podocyte injury. Hyperfiltration, caused by a reduced number of nephrons, is a risk factor for chronic kidney disease. It is therefore important to monitor the formation of nephrons. METHODS: Urine samples were collected from infants within 1-2 days of birth, with follow-up sampling for preterm infants at 37-39 weeks of corrected age. Urinary levels of podocalyxin (PCX), β2-microglobulin (β2MG), N-acetyl-ß-D-glucosaminidase (NAG), total protein (TP), microalbumin (mAlb) and creatinine were measured and the relationship between these markers evaluated. RESULTS: Seventy-nine neonates were enrolled in this study. Urinary levels of PCX at birth were higher than normal adult reference values, with levels increasing up to a gestational age of 36 weeks (p = 0.0242). At 37-39 weeks corrected age, urinary levels of PCX decreased to adult levels. The levels of PCX in the urine at birth were not correlated to urinary levels of β2MG, NAG, TP and mAlb. CONCLUSIONS: An increased urinary level of PCX may be a marker of both active nephron formation and podocyte injury sustained at birth. As such, changes in urinary levels of PCX are likely to reflect adaptation of renal function to the extra-uterine environment.
Authors: Yashpal S Kanwar; Jun Wada; Sun Lin; Farhad R Danesh; Sumant S Chugh; Qiwei Yang; Tushar Banerjee; Jon W Lomasney Journal: Am J Physiol Renal Physiol Date: 2004-02
Authors: Maria M Rodríguez; Alexander H Gómez; Carolyn L Abitbol; Jayanthi J Chandar; Shahnaz Duara; Gastón E Zilleruelo Journal: Pediatr Dev Pathol Date: 2004 Jan-Feb