Role of Urinary Biomarkers TIMP-2 and IGFBP7 in Predicting Acute Kidney Injury in Critically Ill Trauma Patients: A...

Acute kidney injury (AKI) occurs in 15-50% of trauma patients and worsens outcomes. Early identification of high-risk individuals may enable reno-protective strategies. Urinary tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) have shown promise in predicting AKI in various settings, but their utility in critically ill trauma patients remains unclear. This study aimed to evaluate the combined urinary biomarker product (TIMP-2) × (IGFBP7) for early AKI prediction in this group.

This prospective observational study was conducted at a tertiary care center in India. Critically ill trauma patients aged 18-65 years admitted to the critical care unit were enrolled and followed for AKI development (KDIGO criteria). Injury Severity Score (ISS) and APACHE II scores were recorded at admission. Urine samples collected at admission and 24 hours post-admission were analyzed for TIMP-2 and IGFBP7 using ELISA-based kits. Associations between biomarker levels, AKI occurrence, and need for renal replacement therapy (RRT) were assessed, along with clinical and hemodynamic parameters.

Seventy-nine patients were included; 14 (17.7%) developed AKI. Median APACHE II scores were 11 (7-18) vs 9 (7-11), and ISS scores 34 (25-34) vs 25 (25-34) in AKI and non-AKI groups, respectively. The ROC-AUC for (TIMP-2) × (IGFBP7) was 0.49 at admission and 0.57 at 24 hours. A 24-hour cut-off of 0.008 (ng/mL)²/1,000 yielded 85.7% sensitivity, 27.7% specificity, NPV 90%, and PPV 20.3%.

Urinary (TIMP-2) × (IGFBP7) measured at admission did not show any significant discriminating power. However Urinary (TIMP-2) × (IGFBP7) measured 24 hours after admission may help identify critically ill trauma patients at risk of AKI.

Parthiban M, Cherian A, Kundra P, Priyamvada PS, Bobby Z, Senthilnathan M. Role of Urinary Biomarkers TIMP-2 and IGFBP7 in Predicting Acute Kidney Injury in Critically Ill Trauma Patients: A Prospective Observational Study. Indian J Crit Care Med 2025;29(11):936-941.