leukocitaesteráz

Leukocyte esterase, often abbreviated as LE, is an enzyme found in leukocytes, commonly known as white blood cells. Specifically, it is a serine esterase. The presence of leukocyte esterase in biological fluids, such as urine, is a significant indicator of inflammation, particularly when it is associated with the presence of white blood cells.

In clinical diagnostics, leukocyte esterase testing is primarily performed on urine samples. A positive result suggests that leukocytes are present in the urine, a condition known as pyuria. Pyuria can be caused by a variety of conditions, most commonly urinary tract infections (UTIs). It can also indicate other inflammatory processes in the urinary tract, kidney infections, or even certain non-infectious inflammatory conditions.

The test is typically performed using a dipstick that contains a chemical reagent. When the dipstick is dipped into a urine sample, the leukocyte esterase enzyme, if present, reacts with the reagent, causing a color change. The intensity of the color change corresponds to the amount of enzyme present and thus the degree of leukocyte presence.

While a positive leukocyte esterase test is a strong indicator of inflammation, it is not specific to any single cause. Therefore, it is usually interpreted in conjunction with other urinalysis findings, such as the presence of nitrites or bacteria, and clinical symptoms to arrive at a diagnosis. A negative test generally suggests the absence of significant inflammation or infection in the urinary tract.