229 - Trends of urinary biomarkers in preterm newborns from birth to 4 months corrected age and the effect of gestational age and birth weight

Saturday, April 29, 2023

3:30 PM – 6:00 PM ET

Poster Number: 229
Publication Number: 229.242

Arwa Nada, Le Bonheur Children's Hospital, Memphis, TN, United States; John D. Mahan, John D Mahan, Professor of Pediatrics, Nationwide Children's/The Ohio State University, Columbus, OH, United States; Elizabeth Bonachea, Nationwide Children's Hospital, Dublin, OH, United States; Susan E. Ingraham, Kapi'olani Medical Center for Women and Children, Honolulu, HI, United States

Presenting Author(s)

Arwa Nada, MD, MSc. (she/her/hers)

Associate Professor of Pediatric Nephrology
Le Bonheur Children's Hospital & St. Jude Children’s Research Hospital. UTHSC
Memphis, Tennessee, United States

Background:

Urinary biomarkers are promising noninvasive tool to diagnose neonatal AKI specifically in preterm (PT) newborns. Yet, using the urinary biomarkers in PT can be challenging due to the population heterogenicity & the ongoing nephrogenesis that can affect the urinary biomarkers levels. There is limited data on the postnatal trends of urinary biomarkers in PT & the effect of gestational age (GA) & birth weight (BWT) on these biomarkers’ levels

Objective: 1. Examine trends of urinary biomarkers in PT from birth to 4 months corrected age (CA) in comparison to full term (FT)
2. Examine effect of GA & BWT on these levels

Design/Methods: Prospective study

We collected urine from 2 cohorts:

1. Group I: PT group (25 to < 33 weeks GA)
Urine samples were collected at 3 time points from the same cohort and the group was subdivided into 3 groups
1st: urine collected from 30 PT around postnatal day 14 (Group IA)
2nd: urine collected from 27 PT when they reached FT corrected age (FT-CA) (group IB)
3rd: urine collected from 21 PT when they reached 4 months CA (group IC)

2. Group II: 20 FT babies. Urine was collected during the first week of life

Exclusion Criteria:AKI, CAKUT, sepsis, UTI, congenital heart disease with hemodynamic instability, babies on ECMO, babies with chromosomal abnormalities, babies with Bell stage III NEC
All urine samples from PT & FT babies were collected using sterile cotton balls in the diaper

Biomarkers measured using ELISA & normalized values to urine creatinine (Ucr) were calculated

Results:
VEGF, CysC & NGAL levels significantly down trended over time to reach FT level at 4 months CA. B2M levels significantly down trended but levels were significantly lower than group II even after reaching 4months CA. αGST levels continued to uptrend until 4 months CA & were almost undetected in group II. KIM-I & EGF up trended overtime & continued to be significantly higher than group II even at 4 months CA. Calbindin followed an up trending pattern but reached FT levels at 4 months CA (Table I)

In Group IA: EGF had significant positive correlation with GA & BWT. NGAL & VEGF had significant negative correlation with GA & BWT. CysC had significant negative correlation with BWT but no correlation with GA. B2M, αGST, calbindin, and KIM1 had no significant correlation with GA or BWT (Table II)

Conclusion(s):
Urinary biomarkers follow specific trend in PT newborns and some have correlation with BWT & GA. These factors should be taken in consideration when using these biomarkers to diagnose AKI. Additionally, these trends can offer another insight into the ongoing nephrogenesis in PT newborns