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Developmental characteristics of urinary coproporphyrin I/(I + III) ratio
Author(s) -
Kunikata Jun,
Okada Hitoshi,
Itoh Susumu,
Kusaka Takashi
Publication year - 2016
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1111/ped.12965
Subject(s) - medicine , urinary system , urine , gestational age , renal function , pediatrics , physiology , gastroenterology , endocrinology , pregnancy , genetics , biology
Background The ratio of urinary coproporphyrin (UCP) I to total urinary coproporphyrin I and III [UCP {I/(I + III)]] serves as a biomarker of the ATP‐binding cassette, sub‐family C, member 2 ( ABCC2 ) function. The aim of this study was to clarify the characteristics of the developmental pattern of UCP [I/(I + III)] in order to estimate ABCC2 function in children, especially in the neonatal period, by measuring it throughout the entirety of childhood. Method Measurement of UCP [I/(I + III)] was done high‐performance liquid chromatography, using urine samples collected from children from 1 day to 15 years old, involving one sample per child. Urine samples from children with liver and kidney disease and urinary tract infection were excluded. Results UCP [I/(I + III)] varied widely in infants younger than 6 months old, and was ≥0.3 in 80% of the infants. In contrast, it decreased to <0.30, the lowest, at 1–2 years old. In the 0–6‐month‐old group, no significant correlation was noted between postnatal age and UCP [I/(I + III)], but a moderate inverse correlation was noted between corrected gestational age and UCP [I/(I + III)]. Conclusion UCP [I/(I + III)] is inversely correlated with corrected gestational age and is lowest at 1–2 years old. This suggests that ABCC2 activity is correlated with corrected gestational age and is highest at 1–2 years old.