Study Suggests Expanded Utility for Point-of-Care Biomarker: Plasma NGAL May Predict Renal Recovery in Pneumonia Patients with Acute Kidney Injury

According to a study published in Kidney International, plasma neutrophil gelatinase-associated lipocalin (pNGAL), a biomarker that aids in the early detection of acute kidney injury (AKI), may also be useful in predicting the recovery of renal function in patients suffering from AKI.

Patients hospitalized for community-acquired pneumonia frequently develop complications that lead to AKI, and a number of these patients develop severe AKI that leaves them dependent upon dialysis or renal replacement therapy (RRT). While several recent studies have demonstrated pNGAL’s utility in the prediction and identification of AKI, as well as the assessment of AKI severity, little research exists on the biomarker’s role in predicting recovered renal function in AKI patients.

Consequently, a group of investigators led by John Kellum, M.D., University of Pittsburgh, sought to study whether pNGAL levels could predict recovered renal function in patients with community-acquired pneumonia and severe AKI.

In this study, 1,839 patients were identified with community-acquired pneumonia, and 631 developed AKI. Of the patients who developed AKI, 181 met the criteria for severe AKI (defined as RIFLE-F Failure criteria), and, of those, 93 recovered renal function (51.4%). Patients were considered to have recovered renal function if they remained alive without persistent, severe injury or did not require RRT at the time of hospital discharge. pNGAL concentrations were measured with the Alere Triage® NGAL point-of-care test in patient samples that were collected at the time of severe AKI diagnosis.

Patients who did not recover renal function had significantly higher median concentrations of pNGAL (371ng/mL; IQR 201-519) than patients who met the criteria for recovery (165ng/mL; IQR 113-266). Based on these results, the researchers concluded that pNGAL measurements in patients with severe AKI can predict which patients will recover renal function.

“Today, clinicians have to make severe AKI treatment decisions based on limited data,” said Dr. Kellum, the study’s lead investigator. “A biomarker test that helps clinicians rapidly risk stratify patients on the basis of their likelihood for renal recovery could assist in the more timely and effective management of these patients.”

Severe kidney injury often leads to the need for renal replacement therapy, which is costly, can create serious complications, and is associated with increased mortality. For these reasons, clinicians are reluctant to initiate RRT in patients who may recover renal function without such therapy. Patients who ultimately need RRT, however, have been shown to experience better outcomes the earlier therapy begins. When used at the point of care, the Alere Triage® NGAL test provides critical data that may help clinicians detect AKI early, assess disease severity, predict which patients will recover renal function, and make appropriate treatment decisions.