Urine IL-18 is a Biomarker of Early Acute Kidney Injury (AKI)

BUN and serum creatinine are not very sensitive and specific markers for the diagnosis of AKI as they are influenced by many renal and non-renal factors independent of kidney function. IL-18 is released into the urine by the injured kidney, analogous to the troponin release by injured myocardial cells after myocardial infarction, and is a more sensitive and specific early marker of AKI than BUN and serum creatinine. The most recent data on urine IL-18 comes from the Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury (TRIBE-AKI) study. In 311 children and 1219 adults, urine IL-18 was increased in the first 6 hours after cardiac surgery in AKI patients that later developed a doubling of serum creatinine or the need for dialysis. In 2006, a patent was issued to inventors Charles L. Edelstein and Chirag R. Parikh entitled “Methods for detection of IL-18 as an early marker for the diagnosis of acute renal failure and predictor of mortality”. In addition to IL-18, patents have been issued for neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule 1 (KIM-1), Netrin-1, Gro-alpha (also known as CXCL1), heat shock protein-72, mannose- binding lectin (MBL), urinary cytokines and chemokines, aprotinin, and microalbumin as early diagnostic biomarkers of AKI. Also, there is a patent application for using proteomics for the discovery of biomarkers for the early detection of renal disease. Keywords: Acute kidney injury, biomarker, interleukin-18, ischemic AKI, HMGB1, Interstitial inflammation, Cytokines, nephrotic syndrome, urinary tract infections.