Detection of septic shock in acute kidney injury by endotoxin activity assay (EAA) and plasma neutrophil gelatinase-associated lipocalin (NGAL) measurement

Abstract

Endotoxin activity assay (EAA) is an ex vivo diagnostic test utilizing the biological response of patient neutrophils. Neutrophil gelatinase-associated lipocalin (NGAL) is a new acute kidney injury (AKI) biomarker produced not only by renal tubular epithelial cells but also by neutrophils. To date, several investigations have elucidated the role of neutrophil activation in AKI. Nevertheless, it remains unclear whether these assays are influenced by the condition of AKI. We measured EA values and plasma NGAL in 36 severe AKI patients who needed renal replacement therapy. Results show that the degree of renal dysfunction did not significantly influence EA values. Nine patients who had severe gram-negative rod infections that eventually caused septic shock showed significantly higher EA values and plasma NGAL levels. The combination of EAA and plasma NGAL measurement was able to detect septic shock with high sensitivity and specificity.