Summary :
The Leukocyte Esterase urine test is commonly used to screen for urinary tract infections and other conditions that cause inflammation of the urinary tract.
This article explains how the test works, how it is performed, and what the results mean. It also discusses the limitations and potential pitfalls of the test.
Summary :
Leukocyte esterase is an esterase-like enzyme produced by certain types of white blood cells (also called leukocytes). This enzyme is mainly used as a marker to detect the presence of leukocytes in the urine.
It is a simple and rapid screening test that simply requires a clean urine catch to be performed in your home or in a medical setting. A positive leukocyte esterase urine test is often indicative of urinary tract infections (UTIs).
It is usually performed using a test strip or an automated analyzer. Both methods are widely used and can provide reliable results when used correctly.
It is important to note that the leukocyte esterase test is not a definitive diagnostic tool and should be used in conjunction with other tests, such as the nitrite urine test, and the patient's clinical presentation to arrive at a diagnosis.
Measurement of leukocyte esterase using dipstick
If you receive a positive leukocyte esterase result that suggests a high level of leukocytes in your urine, it often indicates inflammation, infection or other urinary system issues (See causes of leucocytes in urine).
A negative Leukocyte Esterase test result is considered normal. This means that leukocytes are not detected in the urine sample and suggests that there is likely no significant inflammation or infection in the urinary tract
The Leukocyte Esterase Test is designed to detect the presence of an enzyme called leukocyte esterase, which is released by certain types of white blood cells, including neutrophils, macrophages, and eosinophils, when they are present in the urine.
The color intensity is proportional to the number of leukocytes in a sample ranging from lavender to purple. Results are reported semi-quantitatively as negative, trace, 1+, 2+, or 3+ (or negative, trace, small, moderate, large).
The Leukocyte Esterase Test is a simple, non-invasive procedure that can be performed in a clinical setting or at home using a test strip. Here are the main steps:
Note : The most accurate results are obtained on fresh, uncentrifuged and well-mixed samples at room temperature.
A leukocyte esterase test is read by comparing the color of the test strip to a color chart provided by the manufacturer. The color of the test strip will change depending on the activity level of leukocyte esterases in the urine sample. As the leukocyte concentration increases, the color of the pad changes from light beige to dark or bright purple.
Leukocyte esterase test results
The number of white blood cells per microliter varies slightly depending on the standardized procedure used. Normally, a few leukocytes are present in the urine: 0 to 8 per high magnification field, or about 10 white blood cells per microlitre.
An increased number of white blood cells in the urine indicates infection or inflammation anywhere in the urinary tract. A combination of positive results for leukocytes and nitrites in urine is a good indicator of urinary tract infections (Cystitis, Kidney infection, etc.).
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