Urinary tissue inhibitor of metalloproteinase-2 as an early predictor for acute kidney injury in critically ill children

Abstract

Objectives: Acute kidney injury (AKI) is one of the most devastating complications
of critical illness in children. Serum creatinine (Scr) is considered the gold standard
for AKI diagnosis yet noted to be late and inaccurate. This raises the need for an early
and accurate biochemical parameter for the early detection of AKI. This research
aimed to explore the role of urinary tissue inhibitor metalloproteinase 2 (TIMP-2) in
the early prediction of AKI, compared to standard biomarkers, in critically ill children
admitted to pediatric intensive care unit (PICU). Urine TIMP2 was previously explored
in multiple adult studies and showed promising results; however, the study of its role
in pediatric population was limited.
Methods: This study was a prospective cohort study including 42 critically ill children
who are at increased risk of AKI. Cases were recruited from the PICU in the Children’s
Hospital of Ain-Shams University, Cairo – Egypt over 10 months’ duration. Urine
samples were collected to measure urinary TIMP-2 and blood samples were taken to
measure the levels of Scr, creatinine clearance, and blood urea nitrogen. Urine output
in 24 h was also calculated.
Results: Urinary TIMP-2 showed considerably higher levels in AKI compared to
non-AKI patients as early as day 1, whereas increased levels of Scr and decreased
urine output were noticed later (day 3 and day 5, respectively). A notable correlation
existed between TIMP-2 at day 1 and creatinine at day 3.
Conclusion: The present study revealed that urinary TIMP-2 could have an important
role in the early prediction of AKI before the increase in Scr and more deterioration
in kidney functions.