Normal values of urine total protein- and albumin-to-creatinine ratios in term newborns.
It is important to have an accurate assessment of urinary protein when glomerulopathy or kidney injury is suspected. Currently available normal values for the neonate population have limited value, in part because they are based on small populations and obsolete creatinine assays. We have performed a prospective study with the aim to update the normal upper values of the urinary total protein-to-creatinine and albumin-to-creatinine ratios in term newborns.



Urine samples were collected from 277 healthy, full-term newborns within the first 48 hours (D0-1) and between 72 and 120 h of life (D3-4). Total protein, albumin, creatinine and osmolality were measured and the upper limit of normal (upper-limit) values determined.



At D0-1 and D3-4, the upper-limit values for the total protein-to-creatinine ratio were 1431 and 1205 mg/g (162 and 136 g/mol) and those for the albumin-to-creatinine ratio were 746 and 301 mg/g (84 and 34 g/mol), respectively. The upper-limit values were significantly higher at D0-1 than at D3-4 only for the albumin-to-creatinine ratio.



This study determined the upper limit of normal values for urinary total protein-to-creatinine and albumin-to-creatinine ratios in the largest population of newborns studied to date. These values can therefore be considered as the most clinically relevant data currently available for the detection and diagnosis of glomerular injury in daily clinical practice in this population.
Collection Biologique, Hôpital de la Mère et de l'Enfant (CB-HME), CHU Limoges, Limoges, France. chahrazed.elhamel@unilim.fr.|Service de pédiatrie, Hôpital de la mère et de l'enfant, CHU Limoges, Limoges Cedex, France. chahrazed.elhamel@unilim.fr.|Comité de l'hôpital de la mère et de l'enfant pour la recherche clinique (CHREC), CHU Limoges, Limoges, France. chahrazed.elhamel@unilim.fr.
Chahrazed
C
El Hamel
Laboratoire de biochimie, CHU Limoges, Limoges, France.
Thierry
T
Chianea
Service de pédiatrie, Hôpital de la mère et de l'enfant, CHU Limoges, Limoges Cedex, France.
Séverine
S
Thon
Service d'obstétrique, CHU Limoges, Limoges, France.
Anne
A
Lepichoux
Collection Biologique, Hôpital de la Mère et de l'Enfant (CB-HME), CHU Limoges, Limoges, France.|Comité de l'hôpital de la mère et de l'enfant pour la recherche clinique (CHREC), CHU Limoges, Limoges, France.|Laboratoire de cytogénétique, CHU Limoges, Limoges, France.
Catherine
C
Yardin
Collection Biologique, Hôpital de la Mère et de l'Enfant (CB-HME), CHU Limoges, Limoges, France.|Service de pédiatrie, Hôpital de la mère et de l'enfant, CHU Limoges, Limoges Cedex, France.|Comité de l'hôpital de la mère et de l'enfant pour la recherche clinique (CHREC), CHU Limoges, Limoges, France.
Vincent
V
Guigonis
D000419:Albuminuria / Q000652:urine*; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000652:urine; D008297:Male; D009994:Osmolar Concentration; D011446:Prospective Studies; D011507:Proteinuria / Q000652:urine*; D012016:Reference Values; D020711:Threshold Limit Values; D016482:Urinalysis
D003404:Creatinine
Albuminuria; Creatinine; Normal limits; Osmolality; Proteinuria; Term neonates