Urinary Biomarkers for Screening High-Risk Urodynamic Phenotypes in Early Spinal Cord Injury: A Pilot Study.

INTRODUCTION

Neurogenic bladder (NB) following spinal cord injury (SCI) is associated with significant morbidity, yet early characterization remains limited. Urodynamic studies (UDS), the gold standard for evaluation, are not routinely performed early after SCI due to unclear guidelines and limited access. We evaluated whether urinary biomarkers could identify high-risk bladder phenotypes early after SCI.

MATERIALS AND

METHODS

We conducted a prospective cohort study of 45 individuals with acute SCI (≤ 6 weeks post-injury), including 35 catheter-dependent participants who underwent UDS and 10 spontaneously voiding controls without UDS. Urine samples were analyzed by nine biomarkers using ELISA. High-risk bladder was defined as detrusor overactivity (DO), detrusor sphincter dyssynergia (DSD), elevated detrusor pressure (≥ 40 cm H2O), or low compliance (< 15 mL/cm H2O). Biomarker performance was assessed using penalized regression with bootstrap-corrected metrics.

RESULTS

Individual biomarkers demonstrated moderate discrimination, including NGAL for DO (AUC 0.75), NGAL for DSD (AUC 0.84), and RANTES/CCL5 for elevated detrusor pressure (AUC 0.73). A multivariable panel improved detection of high-risk bladder (AUC 0.73, 95% CI 0.59-0.89). At a sensitivity-optimized threshold, the model achieved sensitivity 0.94, negative predictive value 0.92, and negative likelihood ratio 0.16. Model discrimination was preserved after accounting for urinary inflammation, although individual biomarkers showed differential sensitivity.

CONCLUSIONS

Urinary biomarkers show promise as a noninvasive approach to identify individuals with early SCI at risk for adverse urodynamic findings. This approach may support earlier risk stratification and targeted use of UDS during inpatient rehabilitation. Larger studies are needed to validate these findings and define their clinical role.

TRIAL REGISTRATION: This study was conducted as part of a registered clinical trial (ClinicalTrials.gov Identifier: NCT04350359).