Neutrophil gelatinase-associated lipocalin (NGAL): a promising biomarker of contrast-induced nephropathy after computed tomography.

Contrast-induced nephropathy (CIN) is a common cause of hospital-acquired acute kidney injury (AKI) and a source of significantly increased short- and long-term mortality. Studies of large cohorts have revealed that more than half of these cases are in subjects undergoing cardiac catheterization and intra-arterial coronary angiography, and nearly a third follow computed tomography (CT) scans. Neutrophil gelatinase-associated lipocalin (NGAL) represents an early predictive troponin-like biomarker for AKI. Its role in the timely diagnosis of CIN has already been examined in adults and children undergoing coronary angiography and a meta-analysis revealed a very good performance of plasma or urine NGAL in the prediction of CIN. Much of these data have been extrapolated to patients receiving intravenous (IV) contrast agent for CT scans, although major differences in patient populations, contrast volume administered and intra-procedural complications between the two settings exist. In this context, a recent prospective study by our group evaluated plasma NGAL, measured using standardized Τriage® NGAL test (Biosite Incorporated, San Diego, CA) at baseline and 6-h post-procedure, for early detection of CIN among hospitalized patients undergoing elective contrast-enhanced CT. CIN, defined as an increase in serum creatinine (SCr) of >25% or >0.5 mg/dL from baseline within 48-h post-procedure, was found in 8.51% of subjects. In contrast, significant elevation of plasma NGAL was found at 6-h post-procedure with excellent performance characteristics. This review presents the current status of NGAL in the prediction of CIN after IV contrast administration among hospitalized patients undergoing elective contrast-enhanced CT.