Urinary NGAL-Positive Acute Kidney Injury and Poor Long-term Outcomes in Hospitalized Patients

Area of Science:

• Nephrology
• Biomarker Discovery
• Renal Medicine

Background:

• Neutrophil gelatinase-associated lipocalin (NGAL) is a recognized biomarker for acute kidney injury (AKI).
• Urinary NGAL (uNGAL) predicts short-term adverse outcomes in AKI patients.
• The long-term predictive capability of uNGAL in AKI has remained largely uninvestigated.

Purpose of the Study:

• To investigate the long-term predictive value of urinary NGAL (uNGAL) in patients diagnosed with hospital-acquired acute kidney injury (AKI).
• To assess the association between uNGAL levels at AKI diagnosis and composite outcomes of mortality and end-stage renal disease (ESRD).

Main Methods:

• Prospective observational study involving 145 patients with hospital-acquired AKI.
• Assessment of long-term predictive value of uNGAL using Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) criteria.
• Defined composite outcome as all-cause mortality or development of ESRD within a 6-month follow-up period.

Main Results:

• Higher uNGAL levels correlated significantly with poorer long-term outcomes.
• Patients in the highest uNGAL quartile (≥362 μg/l) had a 3.7-fold increased risk of adverse outcomes.
• Elevated uNGAL independently predicted mortality and ESRD development, even in AKI survivors not requiring dialysis.

Conclusions:

• Elevated urinary NGAL levels at the time of AKI diagnosis are a significant predictor of adverse long-term outcomes.
• uNGAL serves as a robust independent prognostic marker for mortality and progression to ESRD post-AKI.
• These findings highlight the utility of uNGAL in risk-stratifying AKI patients for long-term prognosis.