Leukocyte esterase

Leukocyte esterase is an enzyme released predominantly by neutrophils (a type of white blood cell) during immune activation at sites of infection or inflammation[1][3]. It hydrolyzes ester bonds in various substrates, and its activity serves as an indicator of the presence of leukocytes in bodily fluids, such as urine or ascitic fluid[1][3]. Leukocyte esterase testing is widely used in clinical laboratories as a rapid, non-invasive biomarker for detecting urinary tract infections, spontaneous bacterial peritonitis, and other inflammatory conditions, due to its strong correlation with leukocyte infiltration in fluids[1][3]. However, the molecular identity of "leukocyte esterase" is imprecise, as it represents a group of related ester-hydrolyzing enzymes rather than a single, specifically characterized protein or gene. As a result, leukocyte esterase is not a discrete molecular therapeutic target, receptor, or defined enzyme; instead, it is a test reagent and functional marker for white blood cell activity[1][3]. - Because "leukocyte esterase" refers to an enzymatic activity rather than a single, structurally unique molecule, it is not a drug target, receptor, or protein family—this makes the entity “not a therapeutic target” and thus is_incorrect=true for structured databases requiring specific molecular targets. - There is no defined mechanism of action or safety concern directly associated with targeting leukocyte esterase. Its clinical role is as a diagnostic biomarker for inflammation/infection, not as a molecular target for therapeutics[1][3].

Other names

White blood cell esteraseWBC esterasegranulocyte esteraseunsonicated white blood cell elastase