How to manage eosinophilia in patients undergoing dialysis?

Management of Eosinophilia in Dialysis Patients

Eosinophilia in dialysis patients should be evaluated systematically for underlying causes, with treatment directed at the specific etiology when identified, and corticosteroid therapy considered for idiopathic cases or those with evidence of end-organ damage.

Evaluation of Eosinophilia in Dialysis Patients

Initial Assessment

• Define severity of eosinophilia:
  • Mild: >0.5 × 10⁹/L
  • Moderate: >1.5 × 10⁹/L
  • Severe: >5.0 × 10⁹/L 1

Common Causes in Dialysis Patients

1. Dialysis-related reactions:

   • Allergy to dialysis components (membrane, tubing, sterilants)
   • More common with older membranes but still occurs with modern materials 2

2. Parasitic infections:

   • Second most common cause of secondary eosinophilia worldwide 1
   • Particularly important in returning travelers and migrants

3. Medication reactions:

   • New medications, especially antibiotics or ACE inhibitors 2

4. Idiopathic hypereosinophilic syndrome:

   • Diagnosis of exclusion after ruling out other causes 3

Diagnostic Approach

Laboratory Evaluation

• Complete blood count with differential
• Peripheral blood smear
• Comprehensive metabolic panel with liver function tests
• Serum tryptase
• C-reactive protein 1

Specific Tests for Dialysis Patients

• Drug-induced lymphocyte stimulation tests for suspected medication reactions
• Evaluation for dialysis component allergy:
  • Consider changing dialyzer type or sterilization method
  • Monitor eosinophil counts before and after dialysis 4

Tests for Parasitic Infections

• Stool microscopy (concentrated)
• Strongyloides serology (high priority due to risk of hyperinfection)
• Schistosomiasis serology if relevant travel history
• Other parasite-specific serologies based on travel history and symptoms 5

Evaluation for End-Organ Damage

• Cardiac: Troponin levels, echocardiography
• Pulmonary: Chest imaging
• Gastrointestinal: Endoscopy if symptoms present
• Skin: Evaluation of rashes or pruritus 3

Treatment Algorithm

1. Address Specific Causes

For Dialysis-Related Eosinophilia:

• Change dialyzer membrane type
• Consider different sterilization methods
• If silicone allergy is suspected (especially in peritoneal dialysis), consider patch testing 6

For Parasitic Infections:

• Strongyloidiasis: Ivermectin 200 μg/kg/day for 1-2 days
• Schistosomiasis: Praziquantel 40 mg/kg twice daily for 5 days
• Filariasis: Diethylcarbamazine (specialist consultation required)
• Hookworm: Albendazole 400 mg daily for 3 days 1

For Medication-Induced Eosinophilia:

• Discontinue suspected medication
• Consider alternatives if medication is essential 1

2. Management of Idiopathic Hypereosinophilic Syndrome

When specific causes have been ruled out and eosinophilia persists:

• First-line therapy: Prednisolone 30-60 mg/day
• Monitor response with serial eosinophil counts
• Taper dose gradually once eosinophil count normalizes
• For steroid-refractory cases: Consider hydroxyurea or interferon-α 3

3. Management of Dialysis Intolerance with Eosinophilia

For patients experiencing symptoms during dialysis:

• Premedication with antihistamines
• Consider prednisolone before dialysis sessions
• In severe cases, temporary discontinuation of dialysis with steroid treatment may be necessary 4

Monitoring and Follow-up

• Regular monitoring of eosinophil counts
• Assessment for resolution of symptoms
• Vigilance for end-organ damage, particularly cardiac complications
• For persistent eosinophilia, consider bone marrow examination to rule out hematologic malignancy 1, 3

Special Considerations

• Prevalence of eosinophilia in hemodialysis patients appears to be increasing (4.7% vs 1.5% historically) 2
• Patients with eosinophilia may have lower C-reactive protein levels and are more likely to be using arteriovenous fistulas for access 2
• Prognosis for asymptomatic patients with mild eosinophilia appears favorable 2
• Intradialytic hypotension may be a manifestation of dialysis-related eosinophilia 3

Pitfalls to Avoid

• Don't assume all eosinophilia in dialysis patients is benign or dialysis-related
• Don't overlook parasitic infections, especially in patients with travel history
• Don't delay treatment in patients with evidence of end-organ damage
• Don't miss the opportunity to diagnose strongyloidiasis before immunosuppressive therapy, which could precipitate hyperinfection syndrome