Urine Test Assesses Risk of Developing Acute Kidney Injury

A first-of-a-kind laboratory test to help determine if certain critically ill hospitalized patients are at risk of developing moderate to severe acute kidney injury (AKI) has been approved for marketing.

Current laboratory tests can only assess whether a patient may already have AKI; often, the patient has progressed to moderate to severe AKI before the test results confirm the clinical diagnosis, and critically ill patients are the most at risk for AKI, particularly patients who meet certain factors such as advanced age, diabetes and high blood pressure.

The US Food and Drug Administration (FDA; Silver Springs, MD, USA) review included two clinical studies evaluating the test’s safety and effectiveness. The two studies compared the clinical diagnoses of more than 500 critically ill subjects at 23 hospitals to the test results. The test accurately detected 92% of AKI patients in one study and 76% in the other. In both studies, the test incorrectly gave a positive result in about half of patients without AKI. No other tests currently on the market are FDA-approved or cleared to assess the risk of developing AKI in at-risk patients.

The test, called NephroCheck Test System (Astute Medical; San Diego, CA, USA) detects the presence of insulin-like growth-factor binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases (TIMP-2) in the urine, which are associated with acute kidney injury. Within 20 minutes, the test provides a score based on the amount of the proteins present that correlates to the patient’s risk of developing AKI within 12 hours of the test being performed. The test procedure involves the operator applying a fresh or thawed clinical urine sample mixed with labeled fluorescent conjugate to the NephroCheck Test Cartridge, and then inserting the test cartridge into the Astute140 Meter for incubation, reading, result calculation, and result display.

Alberto Gutierrez, PhD, director of the Office of In Vitro Diagnostics and Radiological Health at the FDA, said, “Early assessment and timely treatment for AKI can help prevent kidney damage and potential associated complications. The NephroCheck provides health care providers with a quick, validated method of assessing a patient’s AKI risk status which may inform patient management decisions.” The FDA reviewed the data for NephroCheck through the de novo premarket review pathway, a regulatory pathway for some low- to moderate-risk medical devices that are not substantially equivalent to an already legally marketed device.

Related Links:
US Food and Drug Administration
Astute Medical