# Biomarkers to Predict Acute Kidney Injury in Patients with Trauma

## TL;DR

This study explores using mitochondrial DNA in urine and low hemoglobin levels to predict acute kidney injury in trauma patients, potentially enabling earlier interventions.

## Contribution

The study identifies urinary mitochondrial DNA copy number and hemoglobin as novel independent predictors of AKI in trauma patients.

## Key findings

- 25 out of 65 trauma patients developed acute kidney injury.
- Lower hemoglobin and higher urinary mtDNA copy number at admission were independent predictors of AKI.
- No significant differences in serum mtDNA copy number were found between AKI and non-AKI groups.

## Abstract

Background and Objectives: Acute kidney injury (AKI) is a common complication in patients with trauma and is associated with increased morbidity and mortality rates. Early identification of patients at risk of AKI may enable timely intervention and improved outcomes. Biomarkers such as urinary mitochondrial DNA copy number (mtDNAcn) may play a role in predicting AKI. However, its role as a predictor of AKI has rarely been studied in patients with trauma. Therefore, the aim of this study was to evaluate the utility of mtDNA for early detection of AKI in this patient population. Materials and Methods: This single-center prospective observational study included patients with trauma admitted to a regional trauma center between July 2022 and July 2023. Serum and urine samples were collected at baseline and at 24, 48, and 72 h to measure mtDNAcn using real-time polymerase chain reaction test. Clinical variables, including hemoglobin (Hb) levels, were also recorded. Results: Among 65 enrolled patients, 25 (38.5%) developed AKI. Patients with AKI showed significantly lower Hb levels and higher urinary mtDNAcn at admission. Multivariate logistic regression analysis identified low Hb and elevated urinary mtDNAcn as independent predictors of AKI. The optimal cutoff value was 10.95 g/dL for Hb and 738.0 copies/μL for urinary mtDNAcn. However, no significant temporal differences in serum mtDNAcn were observed between the AKI and no-AKI groups. Conclusions: Both Hb and urinary mtDNAcn may serve as independent biomarkers for early identification of AKI in patients with trauma. Future studies are warranted to determine optimal targets and validate these findings in larger multicenter cohorts.