FDA allows marketing of the first test to assess risk of developing acute kidney injury

The U.S. Food and Drug Administration has allowed marketing of the NephroCheck test, 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) in the 12 hours following the administration of the test. Early knowledge that a patient is likely to develop AKI may prompt closer patient monitoring and help prevent permanent kidney damage or death.

The kidneys filter waste and extra water out of the blood and are important in controlling blood pressure and other essential body functions. When kidneys are not functioning properly, waste builds up in the body and can cause serious health problems.

AKI is a sudden decline in kidney function, often without early signs or symptoms, following an injury to the kidney caused by a co-existing disease, infection, or other condition. AKI can cause fluid to build up in the body, chest pain, muscle weakness, and permanent kidney damage or chronic kidney disease (the gradual loss of kidney function). 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.

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. NephroCheck 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. No other tests currently on the market are FDA-approved or cleared to assess the risk of developing AKI in at-risk patients.

"Early assessment and timely treatment for AKI can help prevent kidney damage and potential associated complications," said Alberto Gutierrez, director of the Office of In Vitro Diagnostics and Radiological Health at the FDA's Center for Devices and Radiological Health. "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.

The FDA's 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 NephroCheck test results. NephroCheck accurately detected 92 percent of AKI patients in one study and 76 percent in the other. In both studies, NephroCheck incorrectly gave a positive result in about half of patients without AKI.

The NephroCheck Test System is manufactured by Astute Medical based in San Diego, California.