Which biomarker is commonly used to predict prognosis in AKI and is listed as an early predictor?

• A. Neutrophil gelatinase associated lipocalin
• B. Cystatin C
• C. Procalcitonin
• D. BNP

Answer: (A)

In AKI, an early predictor of prognosis relies on markers that reflect immediate tubular injury rather than overall kidney function. Neutrophil gelatinase-associated lipocalin (NGAL) fits this role because it is produced and released quickly by injured renal tubular cells and by neutrophils in response to renal insult. After a kidney injury from ischemia or nephrotoxicity, NGAL levels rise within a few hours—often detectable in blood and urine long before traditional markers like creatinine change. This rapid rise helps identify patients at higher risk of progression, need for dialysis, or death, enabling earlier risk stratification and management decisions.

Cystatin C is a useful marker for estimating glomerular filtration rate and can detect changes sooner than creatinine in some settings, but its strength is in measuring function rather than providing early prognostic information about AKI progression. Procalcitonin mainly signals systemic infection or inflammation and isn’t specific to kidney prognosis. BNP relates to cardiac wall stress and volume status, not direct AKI prognosis.

So, NGAL stands out as the early biomarker best suited for predicting prognosis in AKI.