Laboratories Validate New Clinical Test for Acute Kidney Injury

Using clinical adjudication, a multicenter prospective study validates a simple new urine test for two biomarkers identified for acute kidney injury.

The study validated the performance of the NephroCheck Test, from Astute Medical (San Diego, CA, USA), in assessing critically ill patient risk of developing acute kidney injury (AKI). The abrupt loss of kidney function in AKI usually occurs within 48 hours, making currently used AKI markers insufficient, as they are not detected until several hours after AKI has already begun.

The NephroCheck Test utilizes fluorescence immunoassay technology to detect and measure two urine biomarkers of AKI: tissue inhibitor of metalloproteinase 2 (TIMP-2) and insulin-like growth factor binding protein 7(IGFBP-7) released by kidney cells during acute stress. When assessed together they enable clinicians to begin treating AKI much earlier than current standards. In the study, 420 critically ill patients in 23 medical centers were enrolled. The primary analysis was the ability of the biomarkers to predict moderate to severe AKI within 12 hours of test measurement. AKI was adjudicated by a committee of three independent expert nephrologists who were blinded to the results.

“This first-of-its-kind study utilized clinical adjudication, the most rigorous standard, to prospectively validate two biomarkers for risk assessment of AKI,” said first author Dr. Azra Bihorac of the University of Florida (USA). “Our study found that the product of the two biomarkers can identify a high risk for near-term AKI in a wide range of critically ill patients. These are the very patients needing improved delivery of recommended interventions, such as those included in the KDIGO [Kidney Disease Improving Global Outcomes] guideline.” Unlike heart attack, AKI lacks clinical symptom warning signs in the early stages when intervention is most beneficial. In addition, AKI has been especially associated with higher cost-of-care and length-of-stay in intensive care units.

The validation study was reported by Bihorac A. et al. in the American Journal of Respiratory and Critical Care Medicine, February 21, 2014, online, ahead of print. The Jortani Clinical Trials Laboratories (JCTL) at the University of Louisville (Louisville, KY, USA) were among the independent labs that tested the trial results. As a Clinical Laboratories Improvement Amendments (CLIA)-certified lab, the JCTL has undergone a rigorous review of its facilities and processes to ensure quality in laboratory testing and analyses. Other main laboratories involved included those at the University of California (San Diego, CA, USA), ARUP Laboratories (Salt Lake City, UT, USA), University of Pittsburgh, (Pittsburgh, PA, USA), and University of Florida (Gainesville, FA, USA).

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