Prognostic Biomarker Detects Acute Kidney Injury

A renal injury biomarker in urine or blood detects early subclinical acute kidney injury (AKI) and its adverse outcomes in critically ill patients.

Early testing for the biomarker, neutrophil gelatinase-associated lipocalin (NGAL) may therefore allow earlier conventional medical interventions or introduction of novel therapies to improve the prognosis of AKI.

In a retrospective study, involving 13 international medical organizations, data from 2,322 critically ill adult and pediatric patients was pooled. These same patients did not have diagnostic increases in serum creatinine, which is considered the current gold standard for detecting AKI. The critically ill patients whose data was analyzed primarily had Type 1 cardiorenal syndrome, a common condition in which heart dysfunction causes kidney injury.

The scientists recorded that 40% of the patients showed unexpected early increases in urine or blood NGAL levels, but no increases in serum creatinine. These early increases in NGAL concentration had a much greater risk of adverse medical outcomes than patients who tested negative for NGAL. NGAL positive patients were 16 times more likely to need dialysis, three times more likely to die during hospitalization, and on average, they spent three extra days in intensive care and eight extra days in the hospital.

Prasad Devarajan, MD, is one of the lead authors of the study, and a departmental director at Cincinnati Children's Hospital Medical Center, (Cincinnati, OH, USA). He said, "This study describes a new biomarker (NGAL) that completely outperforms the current serum creatinine-based criteria for the early detection of AKI and its devastating clinical outcomes. We concluded that a substantial numbers of patients might reasonably be classified as having subclinical AKI, even though they do not fulfill current creatinine-based criteria for AKI." The researchers now plan to pursue a prospective multicenter study to further verify the effectiveness of the NGAL test as a prognostic biomarker in a large population of patients in critical care settings. The study was published on April 26, 2011, in the Journal of the American College of Cardiology (JACC).

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Cincinnati Children's Hospital Medical Center