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Abstract: FR-PO114

Serum and Urine FGF23 and IGFBP-7 for the Prediction of AKI in Critically Ill Children

Session Information

Category: Acute Kidney Injury

  • 003 AKI: Clinical and Translational


  • Li, Yanhong, children hospital of Soochow University, SuZhou, China

Fibroblast growth factor 23 (FGF23) and insulin-like growth factor binding protein 7 (IGFBP-7) are novel biomarkers of acute kidney injury (AKI). We compared them with proposed AKI biomarker of cystatin C (CysC), and aimed (1) to examine whether concentrations of these biomarkers vary with age, body weight, illness severity assessed by pediatric risk of mortality III score, and kidney function assessed by estimated glomerular filtration rate (eGFR), (2) to determine the association between these biomarkers and AKI, and (3) to evaluate whether these biomarkers could serve as early independent predictors of AKI in critically ill children.


Serum and spot urine samples were collected from 144 patients during the first 24 hours after pediatric intensive care unit admission. The diagnosis of AKI developed within 120 hours of sample collection was based on the AKI network (AKIN) criteria. AKIN stage 1 was defined as mild AKI, and AKIN stages 2 and 3 were defined as severe AKI.


Of the 144 patients, 21 developed AKI within 120 hours of sample collection, including 11 with severe AKI defined as AKI Network stages 2 and 3. All the serum levels of FGF23, IGFBP-7, and CysC and urinary level of FGF23 were highest among children with lowest eGFR. However, only serum FGF23 levels were independently associated with eGFR after adjustment in a multivariate linear analysis (B =-0.557, P <0.001). Urinary IGFBP-7 (AOR =2.94 per 1,000 ng/mg increase, P =0.035), serum CysC (AOR =5.28, P=0.005), and urinary CysC (AOR =1.13 per 1,000 ng/mg increase, P =0.022) remained significantly associated with severe AKI after adjustment for body weight and illness severity. Urinary IGFBP-7 level was predictive of severe AKI and achieved the AUC of 0.79 (P =0.001), but was not better than serum CysC(AUC =0.89, P <0.001) or urinary (AUC =088, P <0.001) CysC in predicting severe AKI. However, the difference between the two AUCs of either urinary IGFBP-7 (AUC =0.79) and serum CysC (AUC =0.89) (P =0.103) or urinary IGFBP-7 and urinary CysC (AUC =0.88) (P =0.225) did not reach statistically significant.


Serum FGF23 levels were inversely related to measures of eGFR, and an increased urinary IGFBP-7 level was independently associated with the increased risk of severe AKI, but not superior to serum or urinary CysC in predicting severe AKI in critically ill children.