Eosinophils, Urine (Sendout)

Reference Value: 0%

Interpretation: Results of greater than 5% eosinophils are indicative of acute interstitial nephritis; results between 1% and 5% eosinophils are indeterminant.

Collect 10 mL random urine in a sterile, leak-proof container.

• Clean catch, mid-stream samples are preferred to minimize contamination and improve accuracy.
• Collect Monday - Friday only. Expedite transport to the lab. Samples must be processed within 2 hours of collection.

Outside Laboratories: Prepare unstained slides within 2 hours of collection. Random urine specimens will not be accepted.

Processing Instructions:

1. Collect a random urine specimen.
2. Centrifuge 10 mL of a random urine collection.
3. Pour off supernatant. Assess urine sediment for presence of white blood cells (WBC). If no WBCs are seen, the eosinophil test can't be performed. If WBCs are present, prepare slides using the centrifuged sediment.
4. Unstained slide should be prepared within 2 hours of collection.
5. Centrifuge urine in cytospin centrifuge at speed of 750 rpm for 5 minutes.
6. Guidelines for slide preparation. Use the sediment to prepare slides as follows:
   
   • 150 mcL of sample for 1 to 3 WBC/high power field (hpf)
   • 100 mcL of sample for moderate to normal sediment (<50 cell/hpf)
   • 50 mcL of sample for heavier sediment (>50 cells/hpf)
   • 25 mcL for packed fields of sediment

Stability:

• Unpreserved Urine: Ambient: 2 hours; Refrigerated: Unacceptable; Frozen: Unacceptable.
• Prepared Slides: Ambient (preferred): 14 days; Refrigerated: 14 days; Frozen: 14 days.

Forward sample to Hematology for processing as soon as possible.

Hematology:

1. Centrifuge 10 mL of a random urine collection.
2. Pour off supernatant. Assess urine sediment for presence of white blood cells (WBC). If no WBCs are seen, the eosinophil test can't be performed. If WBCs are present, prepare slides using the centrifuged sediment.
3. Unstained slide should be prepared within 2 hours of collection.
4. Centrifuge urine in cytospin centrifuge at speed of 750 rpm for 5 minutes.
5. Guidelines for slide preparation. Use the sediment to prepare slides as follows:
   • 150 mcL of sample for 1 to 3 WBC/high power field (hpf)
   • 100 mcL of sample for moderate to normal sediment (<50 cell/hpf)
   • 50 mcL of sample for heavier sediment (>50 cells/hpf)
   • 25 mcL for packed fields of sediment
6. Forward prepared slides to Sendouts.

Sendouts: Order Mayo Test: EOSU1.

Stability:

• Unpreserved Urine: Ambient: 2 hours; Refrigerated: Unacceptable; Frozen: Unacceptable.
• Prepared Slides: Ambient (preferred): 14 days; Refrigerated: 14 days; Frozen: 14 days.