NGAL is the abbreviation of Neutrophil gelatinase-associated lipocalin, and NGAL is one of the lipid carrier proteins. Recent studies have found that NGAL is an early marker of acute kidney injury as well as an early marker of diabetic nephropathy. NGAL has many functions, including binding and transporting hydrophobic small molecules, participating in inflammation, embryonic development, immune response, signal transduction, and the occurrence and development of various tumors. NGAL can be detected using blood and urine tests.
Different from the diagnostic method of grading standard, NGAL is a single molecule to diagnose AKI. Many studies have reported that NGAL is the most effective predictor of AKI among many markers. In healthy individuals, the average concentration of NGAL in urine was 5.3ng/mL (range 0.7-9.6ng/mL) and the average concentration of NGAL in plasma was 63ng/mL (range 3-106ng/mL). NGAL levels increased sharply after renal injury (within 2h). The concentration of NGAL in urine of randomly selected ICU patients was 110ng/mL to 40000 ng/mL, and the mean concentration of NGAL in plasma was 25ng/mL to 3491ng/mL. Acute renal failure is diagnosed when urine NGAL levels are higher than 350ng/mL or plasma NGAL levels are higher than 400ng/mL.
