Urinary TIMP-2 and IGFBP7 as Prognostic Biomarkers in Non-Critically Ill children with Acute Kidney Injury

Background Early biomarkers of acute kidney injury (AKI) in children may help predict outcomes beyond traditional measures. We evaluated the prognostic value of urinary TIMP-2 and IGFBP7 in hospitalized children with AKI who were not critically ill. Methods In this prospective cohort, 40 children with AKI admitted to Cairo University Children’s Hospital were enrolled. Urinary TIMP-2 and IGFBP7 were measured within 24 hours of AKI diagnosis. Endpoints included recovery, development of acute kidney disease (AKD), progression to chronic kidney disease (CKD), length of hospital stay, ICU admission, and mortality. Results Mean age of the cohort was 6.8 ± 3.8 years, with 55% males. The most frequent cause of AKI was poststreptococcal glomerulonephritis (35%%). AKI was stage 1 in 12.5%, stage 2 in 22.5%, and stage 3 in 65%. Median TIMP-2 and IGFBP-7 levels were not significantly different across AKI stages. Oliguric patients had significantly higher IGFBP7 with a p-value of 0.018. Higher urinary TIMP-2 and TIMP2*IGFBP7/1000 were significantly associated with AKD and prolonged hospitalization. Mortality was 10% and was associated with lower TIMP-2 values. Conclusion Urinary TIMP-2 and IGFBP7 are promising prognostic biomarkers in children with AKI, even outside critical care settings. While not related to AKI stage, progression to CKD or ICU admission, their association with short-term outcomes like progression to AKD and hospital stay highlights their potential role in pediatric risk stratification.