Urinary Presepsin Level Predicts Acute Kidney Injury in the Emergency Room-Comparative Evaluation of Three Urinary Biomarkers: NGAL, L-FABP, and Presepsin-

Background Acute kidney injury (AKI) is a critical complication in emergency medicine. The novel renal biomarker presepsin, when measured in urine, holds promise for improving the specificity of renal injury detection and facilitating the early diagnosis of AKI. This study aimed to directly compare the diagnostic performance of various urinary AKI biomarkers. Methods This single-center, prospective cohort study included 19 unselected adult patients diagnosed with AKI between May 2023 and August 2023. Non-AKI patients were enrolled to establish a baseline for comparison. Urinary levels of neutrophil gelatinase-associated lipocalin (uNGAL), liver fatty acid-binding protein (uL-FABP), and presepsin (uP-SEP) were measured throughout the treatment period. The primary outcome was the diagnosis of AKI based on the Kidney Disease: Improving Global Outcomes (KDIGO) criteria, with a comparative analysis of urinary P-SEP, NGAL, and L-FABP. Results Urinary P-SEP, NGAL, and L-FABP levels were significantly elevated in AKI patients. Notably, uP-SEP demonstrated a positive correlation with uNGAL in the absence of infection. Time-course analyses indicated that the predictive performance of uP-SEP for assessing AKI status was superior to that of other urinary biomarkers, including NGAL and L-FABP. Moreover, urinary P-SEP levels were associated with disease severity. However, in septic patients with AKI, uP-SEP levels did not correlate with KDIGO criteria or the Sequential Organ Failure Assessment (SOFA) score. Conclusions This study highlights the potential utility of uP-SEP as a biomarker for AKI detection. Our findings suggest that uP-SEP exhibits superior discriminatory and monitoring capabilities compared to urinary NGAL and L-FABP. Nevertheless, further research is warranted to elucidate the clinical significance of elevated uP-SEP levels in septic patients.