II. Mechanism

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

III. Normal

  1. Negative

IV. Abnormal: Positive

  1. Urinary Tract Infection
  2. Vaginal contaminant

V. Causes: False negative Leukocyte esterase on Urinalysis

  1. Inadequate time allowed for dipstick reading
  2. Increased Urine Specific Gravity
  3. Urine Glucose present (Glycosuria)
  4. Urine Ketones present (Ketonuria)
  5. Proteinuria
  6. Keflex
  7. Nitrofurantoin
  8. Tetracycline
  9. Gentamicin
  10. Vitamin C

VI. Causes: Positive Leukocyte esterase and negative 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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