Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 76

A positive nitrite test and a negative leukocyte esterase test is an indication of a:

A. Dilute random specimen

B. Specimen with lysed leukocytes

C. Vaginal yeast infection

D. Specimen older than 2 hours

Step 1 of 2

Nitrite reagent strip test:

Nitrate is the normal component of urine which is reduced to nitrite.

• Nitrite is not normally present in urine.

• The test is to detect capability of some bacteria to reduce nitrate to nitrite.

Leukocyte esterase:

• Leukocytes are immune bodies accumulate when there is infection in body.

• Leukocyte esterase (LE) test detects the presence of esterase in WBC (granulocytes) that is eosinophils, basophils, neutrophils which are immune cells.

• Erythrocytes, bacteria, renal tissue cells and lymphocytes do not have esterase.

Negative LE and positive nitrite test indicates that specimen is older than 2 hours.

• Bacteria tend to form in the unpreserved specimen.

• If time exceeds more than 2 hours and its presence is noticeable.

Therefore, “specimen older than 2 hours” indicates negative leukocyte esterase test and positive nitrite test .Hence, the correct answer is option .