The Detection of Leukocyte Esterase Activity in Urine with a New Reagent Strip

Abstract

An evaluation of the Ames Leukostix reagent strips for the detection of leukocyte esterase activity in urine was undertaken to determine the interlot precision and between reader reliability, to compare Leukostix and Chemstrip LN results, and to determine if the Ames Leukostix reagent strip provides an alternative to, or supplement for, the microscopic detection of leukocytes. A total of 412 urines were analyzed with the Ames and Bio-Dynamics reagent strips. The sensitivity and specificity of Leukostix results, relative to a quantitative chamber count, were 89.4% and 90.4%, respectively. Chemstrip LN provided essentially the same results with a sensitivity of 88.8% and specificity of 92.4%. The between-reader and between-lot reproducibility was excellent, with 99% of the results agreeing within half a color block of each other. The sensitivity of the sediment count relative to the chamber count was 68.9% and the specificity, 97.7%. Performance of the sediment count in addition to use of the reagent strip provided little additional information. On the basis of these results, the Ames Leukostix reagent strip is considered to be a suitable alternative to sediment microscopic examination for the detection of leukocytes in urine.

Urine proteomics: the present and future of measuring urinary protein components in disease

“…27 Neutrophil esterase hydrolyses the dipstick substrate (3-hydroxy-5-phenyl-pyrrole esterified with an indoxyl carbonic acid ester) into 3-hydroxy-5-phenyl-pyrrole and indoxyl, which react with a diazonium salt to yield an azo dye.…”

Novel diagnostic method of testing for Helicobacter pylori infection using the rapid leukocyte strip test, Leukostix

“…The rapid leukocyte detection system, Leukostix, which makes use of the property of strips to specifically bind to neutrophil esterase, is a simple and rapid test to detect leukocytes and has been widely used for the diagnosis of urinary tract infection 15 . The use of this system, however, has not been reported for homogenate samples of gastric mucosa.…”

“…After completion of the endoscopic procedure, homogenates (50 µL) of biopsy samples of gastric mucosa made for the quantitative cultivation method to detect H. pylori were dropped onto Leukostix strips (Bayer, Elkhart, IN, USA) to detect tissue neutrophils semiquantitatively. The strips were observed 2 min later and scored by five grades (–), (+/–), (1+), (2+), and (3+) 15 . Samples that were scored (+/–) or higher were judged to be positive.…”

“…The rapid leukocyte strip test, Leukostix, is a simple and easy detection system for leukocytes and uses a strip that has the property to bind to neutrophil esterase. It has been used worldwide to diagnose urinary tract infection 15 . The authors noted the inflammation of gastric mucosa caused by H. pylori infection, which is mainly detected as infiltration of neutrophils, and tried to detect neutrophils in homogenates of biopsy mucosa samples semiquantitatively using Leukostix.…”

“…It has been used worldwide to diagnose urinary tract infection. 15 The authors noted the inflammation of gastric mucosa caused by H. pylori infection, which is mainly detected as infiltration of neutrophils, and tried to detect neutrophils in homogenates of biopsy mucosa samples semiquantitatively using Leukostix. The present study compared results obtained with the presence or absence of H. pylori infection and the amount of H. pylori bacilli in biopsy samples.…”