Leukocyte esterase in urine is an enzyme released by white blood cells (leukocytes) and its presence in a urine sample often indicates a urinary tract infection (UTI). In essence, a test for leukocyte esterase is a screening tool for detecting white blood cells in urine.
Understanding Leukocyte Esterase
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What it is: Leukocyte esterase itself isn't a disease or infection, but rather an indicator. It's an enzyme produced by leukocytes.
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What it indicates: Its presence in urine suggests inflammation in the urinary tract, most commonly due to a bacterial infection.
How the Test Works
The leukocyte esterase test is usually performed as part of a urine dipstick test (urinalysis). A dipstick with chemical pads is dipped into a urine sample. If leukocyte esterase is present, the pad will change color, indicating a positive result.
Interpreting the Results
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Positive Result: A positive leukocyte esterase test suggests the presence of white blood cells in the urine. This often points to a UTI, but can also be caused by other conditions, such as kidney infections or bladder inflammation. A positive test usually prompts further investigation, like a microscopic examination of the urine to count white blood cells and look for bacteria.
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Negative Result: A negative result suggests that there aren't significant numbers of white blood cells in the urine. However, it's important to remember that a negative test doesn't completely rule out an infection, especially if symptoms are present.
Considerations
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False Positives and Negatives: Certain factors can lead to inaccurate results. For example, contamination of the urine sample, medications, or diluted urine can affect the test.
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Further Testing: If the leukocyte esterase test is positive, your doctor will likely order a urine culture to identify the specific bacteria causing the infection and determine the best antibiotic treatment.
In summary, the leukocyte esterase test is a valuable screening tool for detecting potential urinary tract infections. A positive result usually warrants further investigation to confirm the diagnosis and identify the underlying cause.
