Utility of Trend of Nephrocheck® (IGFBP7 × TIMP-2) Biomarker for Early Identification of Acute Kidney Injury in Critically Ill Patients with Sepsis or Respiratory Failure

Introduction: Many studies have shown the association between acute kidney injury (AKI) and morbidity and mortality in the Intensive Care Unit (ICU). Traditional measures of AKI, such as serum creatinine and urine output, fail to show dynamic changes in renal function. A feasibility study was performed to evaluate the Nephrocheck® test system which comprises of two biomarkers (Insulin-like growth factor binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP-2)) to screen for patients at risk for AKI in the ICU and to guide management. Methods: Patients were enrolled between November 2016 and March 2017 with respiratory failure or sepsis with no pre-existing elevation in the creatinine admitted to the ICU. In patients with an initial Nephrocheck® value ≥ 0.3, the primary team was notified and a kidney protective bundle was suggested. A repeat Nephrocheck® test was performed within 24 hours in those patients with initial value ≥ 0.3. Results: Twenty patients were enrolled. Six (30%) patients developed AKI during first week of ICU stay. All six patients had initial Nephrocheck® values ≥ 0.3 that subsequently increased with the second Nephrocheck® test at 24 hours. Seven patients had normal Nephrocheck® values on admission and did not develop AKI. Interestingly, seven patients who had initial Nephrocheck® values ≥ 0.3 that decreased at 24 hours did not develop AKI. Conclusion: The trend of the Nephrocheck® values was more significant than the initial value for the development of AKI. The Nephrocheck® test may be used as an early indicator of development of AKI. However, further studies are needed to determine if nephron-protective interventions can be helpful in mitigating this risk.