Calprotectin and neutrophil gelatinase-associated lipocalin in the differentiation of pre-renal and intrinsic acute kidney injury

BACKGROUND: Urinary calprotectin has recently been identified as a promising biomarker for the differentiation of prerenal and intrinsic acute kidney injury (AKI). The present study compares the diagnostic performance of calprotectin and neutrophil gelatinase-associated lipocalin (NGAL) in this differential diagnosis. METHODS: Urinary calprotectin and NGAL concentrations were assessed in a study population of 87 subjects including 38 cases of intrinsic AKI, 24 cases of prerenal AKI, and 25 healthy controls. Urinary tract obstruction, renal transplantation and metastatic cancer were defined as exclusion criteria. RESULTS: Mean calprotectin concentrations were significantly lower in prerenal (190.2+/-205.7 ng/ml) than in intrinsic AKI (6250.1+/-7167.2 ng/ml, p