Early Diagnostic and Prognostic Value of the Urinary TIMP-2 and IGFBP-7 in Acute Kidney Injury in Critically Ill Children

Background: Acute kidney injury (AKI) is a hidden complication among children within pediatric intensive care units (PICU). Aim: To evaluate the early predictive and diagnostic value of Urinary [TIMP-2]center dot[IGFBP7] to detect AKI in PICU patients. Methods: A case-control study was conducted on 112 children (72 admitted to PICU and 40 healthy controls) Urinary [TIMP-2]center dot[IGFBP7] was measured within 24 hours of PICU admission. Results: Acute kidney injury developed in 52 (72.2%) out of 72 critically ill patients. The AKI group had significantly higher serum creatinine, CRP, and pediatric sequential organ failure assessment score (pSOFA) score (p = 0.001, 0.01, and 0.001, respectively) and significantly lower estimated creatinine clearance (eCCl) (p = 0.001). Urinary [TIMP-2]center dot[IGFBP7] was significantly higher in the AKI group as compared with the non-AKI group (p = 0.007) . The duration of the PICU stay was 1.8-fold higher in the AKI group (p = 0.004). At the time of study enrollment, 7 (13.5%) patients had normal initial eCCl. 26 patients (50.0%) fulfilled the "Risk," 18 patients (34.6%) the "Injury," 1 patient (1.9%) the "Failure" and 0 patient (0%) the "Loss" criteria. Nine (17%) patients progressed to the next higher pediatrics risk, injury, failure, loss, end-stage renal disease (pRIFLE) stage. Urinary [TIMP-2]center dot[IGFBP7] was significantly higher in the "Failure" stage followed by "Injury," stage then the "Risk," stage (p = 0.001). Hypovolemia/ dehydration had the highest [TIMP-2]center dot[IGFBP7] values followed by sepsis. Urinary [TIMP-2]center dot[IGFBP7] was significantly increased in mechanically ventilated and patients who received inotropic medications. Conclusions: [TIMP-2]<middle dot>[IGFBP7] was higher in AKI patients compared with non-AKI ones especially cases with hypovolemia and sepsis. It may predict severe morbidity and mortality because its higher levels in mechanically ventilated children and those on positive inotropic support.