Plasma and urinary sTREM-1 as biomarkers of sepsis-associated acute kidney injury in critically Ill children

Early identification of sepsis-associated acute kidney injury (SA-AKI) is important to enable timely supportive management and reduce further renal injury. However, conventional diagnostic criteria for acute kidney injury (AKI), based on serum creatinine and urine output, may delay early detection. Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) has emerged as a potential biomarker in septic conditions. To evaluate the diagnostic value of plasma and urinary soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in children with sepsis-associated acute kidney injury. This prospective observational cohort study included 50 children with sepsis admitted to the Pediatric Intensive Care Unit, Children's Hospital, Ain Shams University, Cairo, Egypt, between October 2023 and March 2024. Plasma and urinary sTREM-1 levels were measured at the time of sepsis diagnosis according to pediatric Sequential Organ Failure Assessment (pSOFA) criteria. Patients were prospectively followed for the development of SA-AKI, and in those who developed AKI according to pediatric Risk, Injury, Failure, Loss, End-stage kidney disease (pRIFLE) criteria, sTREM-1 levels were reassessed at the time of AKI diagnosis. The median age of the study population was 8.5 months (range 3-24), with a slight female predominance (54%). Plasma sTREM-1 levels were significantly higher in children who developed SA-AKI than in septic children without AKI [222.7 (165.2-325.9) vs 130.3 (85.1-206.2) pg/mL, p = 0.006]. Receiver operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.729, with a cutoff value of 159.6 pg/mL, yielding 80% sensitivity and 60% specificity. Urinary sTREM-1 levels were also significantly higher in children who developed SA-AKI [116.3 (53.9-197.3) vs 68.5 (46.7-112.2) pg/mL, p = 0.045]. ROC analysis showed an AUC of 0.666, with a cutoff value of 62.2 pg/mL, yielding 72% sensitivity and 48% specificity. CONCLUSION: Both plasma and urinary sTREM-1 levels were significantly elevated in children who developed sepsis-associated acute kidney injury. Measurement at sepsis diagnosis may aid early risk stratification, while repeat assessment at AKI diagnosis may provide additional prognostic information. WHAT IS KNOWN: • Early recognition of sepsis-associated acute kidney injury in children is challenging, and conventional diagnostic markers may be delayed. sTREM-1 is an inflammatory biomarker with potential value in sepsis-related organ injury. WHAT THIS STUDY ADDS: • Baseline plasma and urinary sTREM-1 levels were higher in septic children who later developed sepsis-associated acute kidney injury, and both rose further after AKI occurrence. Urinary sTREM-1 also showed strong prognostic value for mortality in children with sepsis-associated acute kidney injury.