II. Mechanism

  1. Neutrophil Granulocytes contain esterases
  2. Positive test suggests pyuria
    1. Dipstick requires 5 minutes to change color

III. Interpretation: Normal

  1. Negative

IV. Interpretation: Positive (Abnormal)

V. Causes: False NegativeLeukocyte esterase on Urinalysis

  1. Inadequate time allowed for dipstick reading (60 to 120 seconds)
  2. Increased Urine Specific Gravity
  3. Urine Glucose present (Glycosuria)
  4. Urine Ketones present (Ketonuria)
  5. Urine Protein present (Proteinuria)
  6. Vitamin C
  7. Enterococcus UTI
  8. Klebsiella UTI
  9. Antibiotics
    1. Cefalexin (Keflex)
    2. Nitrofurantoin (Macrobid)
    3. Tetracycline
    4. Gentamicin

VI. Causes: Positive Leukocyte esterase and negative Urine Culture

  1. Chlamydia
  2. Ureaplasma urealyticum
  3. Balanitis
  4. Bladder Cancer
  5. Nephrolithiasis
  6. Tuberculosis
  7. Urinary tract foreign body
  8. Glomerulonephritis
  9. Medications (Corticosteroid, Cytoxan)
  10. Methenamine

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Related Studies

Ontology: Urine dipstick for leukocyte esterase (C0430381)

Concepts Laboratory Procedure (T059)
SnomedCT 252385000
English Urine dipstick for leuc ester, Urine dipstick for leucocyte esterase, Urine dipstick for leucocytes, Urine dipstick for white cells, Urine dipstick for leukocyte esterase (procedure), Urine dipstick for leukocyte esterase, Urine dipstick for leukocytes
Spanish detección de esterasa leucocitaria en orina con tira reactiva (procedimiento), detección de esterasa leucocitaria en orina con tira reactiva, tira reactiva para detección de leucocitos en orina