Reference ranges and impact of selected confounders on classic serum and urinary renal markers in neonatal period.
OBJECTIVE
Renal injury in term and pre-term neonates may be an antecedent to chronic kidney disease in the child's further life. The aim of the paper was to compile a reference range for selected serum and urinary renal markers in the neonatal period for full-term (FT) and pre-term (PT) newborns.


METHODS
The prospective study included 23 FT infants (birth weight - BW≥2500g and gestational age - GA≥37Hbd) and 32 PT children (BW<2500g and GA<37Hbd) in good general condition, without acute kidney injury (AKI) or sepsis. Between the 4th and 28th DOL, urinary concentrations of the studied renal markers (uCr, uNa, uOsm) were determined on a daily basis, while serum creatinine (SCr) was assessed minimum every 48-72h.


RESULTS
The mean GA and BW of the FT and PT infants were respectively as follows: 38.5±1.7Hbd; 3433±495.2g and 32.7±2.6Hbd; 1836.7±419.8g. For serum glomerular (SCr, eGFR) and tubular markers (FENa, RFI), the median values with normal ranges were compiled. For urinary renal markers (uCr, uNa, uOsm) and those values standardized for kg of body weight, percentile tables for 4-28DOL were elaborated.


CONCLUSIONS
The study has resulted in determining the normal ranges of serum glomerular and tubular renal markers, as well as percentile tables of selected urinary renal parameters during the neonatal period. The percentile tables may prove to be helpful for further standardization of other urinary parameters per urinary creatinine in neonatal population.
Department of Pediatric Nephrology, Faculty of Medicine, Jagiellonian University Medical College, Cracow, Poland. Electronic address: mmiklasz@wp.pl.
Monika
M
Miklaszewska
AGH University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, Department of Electronics, Cracow, Poland.
Przemysław
P
Korohoda
Department of Pediatrics, Faculty of Medicine, Jagiellonian University Medical College, Cracow, Poland.
Przemko
P
Kwinta
Department of Pediatric Nephrology, Faculty of Medicine, Jagiellonian University Medical College, Cracow, Poland.
Katarzyna
K
Zachwieja
Department of Pediatrics, Faculty of Medicine, Jagiellonian University Medical College, Cracow, Poland.
Tomasz
T
Tomasik
Department of Paediatric Nephrology, Wroclaw Medical University, Wroclaw, Poland.
Katarzyna
K
Kiliś-Pstrusińska
Department of Pediatric Nephrology, Faculty of Medicine, Jagiellonian University Medical College, Cracow, Poland.
Dorota
D
Drożdż
D058186:Acute Kidney Injury / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D015415:Biomarkers / Q000097:blood* / Q000652:urine*; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007677:Kidney Function Tests; D007678:Kidney Glomerulus / Q000378:metabolism* / Q000473:pathology; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012015:Reference Standards
D015415:Biomarkers
Acute kidney injury; Neonate; Percentile tables; Reference range; Renal marker