Hansel’s Stain for Detection of Urinary Eosinophils

Purpose

To detect eosinophils in urine

Materials and Reagents
Hansel’s Stain (prepared as below)

Preparation of Hansel’s Stain Solution (if preparing manually)

1. Eosin Y Solution (0.5%)

• Eosin Y: 0.5 g
• Distilled water: 100 mL
  Mix until dissolved.

2. Methylene Blue Solution (0.25%)

• Methylene blue: 0.25 g
• Distilled water: 100 mL
  Mix thoroughly and filter if needed.

3. Hansel Stain Working Solution

• Mix 3 parts Eosin Y with 1 part Methylene Blue
• Let stand for 24 hours before use
• Filter before use

Specimen Collection and Handling

• Sample Type: Fresh, midstream clean-catch urine or body fluid
• Volume: At least 10 mL
• Storage: Process within 1 hour; if delayed, refrigerate at 2–8°C NOT MORE THAN 12 hours

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🔬 Staining Procedure

1. Centrifuge 10–15 mL urine at 1500–2000 rpm for 5 minutes
2. Decant the supernatant, leaving ~0.5 mL of sediment
3. Place one drop of sediment on a clean glass slide
4. Air dry the smear completely
5. Add 2–3 drops of Hansel’s stain to the dried smear
6. Let it stain for 2–3 minutes
7. Gently rinse with distilled water
8. Air dry and observe under light microscope using 40× and 100× (oil) objective

Microscopy and Interpretation

• Eosinophils appear with:
  • Bright red to orange cytoplasm
  • Blue-purple bilobed nuclei
• Count eosinophils per 100 white blood cells
• Report as % eosinophils in urine WBCs
• Hansel’s stain is more sensitive and specific than Wright stain

🟢 Normal: 0–1%
🔴 Significant eosinophiluria: >1%
🔴 Highly suggestive of AIN/CES: >5%

Clinical Significance

1. Acute Interstitial Nephritis (AIN)

• 📌 Most common cause of eosinophiluria
• Often drug-induced (e.g., NSAIDs, antibiotics like penicillin, rifampin)
• Eosinophils infiltrate the interstitium and spill into urine
• Usually accompanied by:
  • Fever
  • Rash
  • Eosinophilia in blood
  • Renal dysfunction (↑creatinine)

2. Allergic (Hypersensitivity) Reactions

• Drug-induced hypersensitivity
• Systemic allergic responses

3. Urinary Tract Infections (UTIs)

• Especially chronic or complicated UTIs
• Eosinophils may appear as part of inflammatory response

4. Eosinophilic Cystitis

• Rare inflammatory bladder condition
• Presents with:
  • Dysuria
  • Hematuria
  • Bladder wall thickening on imaging

5. Prostatitis or Prostatovesiculitis

6. Parasitic Infections (e.g., Schistosomiasis)

• Urinary tract involvement may lead to eosinophiluria
• Common in endemic areas

7. Systemic Disorders

• Churg-Strauss Syndrome (EGPA)
• Loeffler’s syndrome if kidneys are involved
• Other hypereosinophilic syndromes

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References

1. Kleinknecht D, et al. Eosinophiluria in allergic interstitial nephritis. Kidney Int. 1980;17(1):28–33.
2. Vanholder R, et al. Diagnostic value of urinary eosinophils in acute interstitial nephritis. Am J Nephrol. 1989;9(5):402–7.
3. Henry JB. Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Elsevier Saunders; 2011.
4. Brenner & Rector’s The Kidney, 11th Edition, Elsevier, 2020.
5. Kumar & Clark’s Clinical Medicine, 10th Edition, Elsevier.