NGAL (neutrophil gelatinase-associated lipocalin) has become hot news as an early marker of renal injury. However, like many other endogenous biomarker molecules, it is not produced by just one cell type and different pathologies in different tissues can all provoke responses. Results must be interpreted with due regard to concurrent conditions in the individual patient to make the optimal use of this sensitive marker.

Renal expression of neutrophil gelatinase-associated lipocalin (NGAL) increases dramatically after renal ischemia or exposure to nephrotoxic agents. This is reflected by the rapid rise in urinary NGAL reported in children who developed acute renal failure (ARF) after cardiac surgery. The aim of the present study was to ascertain whether urine or plasma NGAL levels, determined by a recently developed ELISA, are useful for diagnosing renal injury leading to ARF in unselected critically ill patients admitted to intensive care.

NGAL (also known as neutrophil gelatinase-associated lipocalin or lipocalin-2) is a new early marker for acute renal injury. Increased levels of NGAL from acute renal injury can be detected in both urine and blood within two hours of the insult.

NGAL, or neutrophil gelatinase-associated lipocalin, is a small, robust protein expressed by neutrophils and various epithelia, including the renal proximal tubules. While initially proposed as a marker for infections and certain adenocarcinomas, it is now apparent that its early and dramatic rise in urine after renal injury may make it a useful marker of such injury.