Leukocyte esterase
Encyclopedia
Leukocyte esterase is a urine test for the presence of white blood cell
s and other abnormalities associated with infection
.
White blood cells in the urine usually indicate a urinary tract infection
. The leukocyte esterase (LE) test detects esterase
, an enzyme released by white blood cells. Positive test results are clinically significant. The LE test is also used to screen for gonorrhea
and for amniotic fluid
infections. The combination of the LE test with the urinary nitrite test
provides an excellent screen for establishing the presence of a urinary tract infection (UTI). A urine sample that tests positive for both nitrite and leukocyte esterase should be cultured for pathogenic bacteria
.
"It has been proposed that the reagent strip for leukocyte esterase designed for the testing of urine (Combur test UX) could be a useful tool for diagnosing [spontaneous bacterial peritonitis] SBP." Braga et al. concluded that the Combur test UX urine screening test is a very sensitive and specific method for diagnosing SBP in cirrhotic patients with ascites."
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...
s and other abnormalities associated with infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
.
White blood cells in the urine usually indicate a urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
. The leukocyte esterase (LE) test detects esterase
Esterase
An esterase is a hydrolase enzyme that splits esters into an acid and an alcohol in a chemical reaction with water called hydrolysis.A wide range of different esterases exist that differ in their substrate specificity, their protein structure, and their biological function.- EC classification/list...
, an enzyme released by white blood cells. Positive test results are clinically significant. The LE test is also used to screen for gonorrhea
Gonorrhea
Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...
and for amniotic fluid
Amniotic fluid
Amniotic fluid or liquor amnii is the nourishing and protecting liquid contained by the amniotic sac of a pregnant woman.- Development of amniotic fluid :...
infections. The combination of the LE test with the urinary nitrite test
Nitrite test
A nitrite test is a chemical test used to determine the presence of nitrite ion in solution.-Chemical method:A common nitrite test can be performed by adding 4 M sulfuric acid to the sample until acidic, and then adding 0.1 M iron sulfate to the solution...
provides an excellent screen for establishing the presence of a urinary tract infection (UTI). A urine sample that tests positive for both nitrite and leukocyte esterase should be cultured for pathogenic bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
.
"It has been proposed that the reagent strip for leukocyte esterase designed for the testing of urine (Combur test UX) could be a useful tool for diagnosing [spontaneous bacterial peritonitis] SBP." Braga et al. concluded that the Combur test UX urine screening test is a very sensitive and specific method for diagnosing SBP in cirrhotic patients with ascites."