What are the guidelines for managing Allergic Bronchopulmonary Aspergillosis (ABPA)?

Guidelines for Managing Allergic Bronchopulmonary Aspergillosis (ABPA)

For patients with ABPA, oral prednisolone (0.5 mg/kg/day for 2-4 weeks, tapered over 4 months) or oral itraconazole for 4 months are the recommended first-line treatments for acute ABPA, with treatment decisions based on disease classification and symptom severity. 1

Initial Assessment and Classification

• ABPA should be classified as either ABPA with bronchiectasis (ABPA-B) or ABPA without bronchiectasis (ABPA-S) to guide treatment decisions 1
• Asymptomatic ABPA patients should not receive systemic therapy 1
• ABPA-S should be managed like asthma without specific ABPA treatment unless there is poor asthma control or recurrent exacerbations despite optimal asthma management 1

First-Line Treatment Options for Acute ABPA

Oral Corticosteroids

• Recommended dosage: 0.5 mg/kg/day of prednisolone for 2-4 weeks, tapered and completed over 4 months 1
• Preferred initial therapy for most patients with symptomatic ABPA-B 1
• Monitor for side effects including osteopenia (correct vitamin D deficiency to minimize this risk) 1

Oral Itraconazole

• Recommended as initial therapy when systemic glucocorticoids are contraindicated 1
• Standard course: 4 months of treatment 1
• Therapeutic drug monitoring should be performed (target trough itraconazole levels ≥0.5-1 mg/L) 1
• Note that itraconazole increases plasma levels of methylprednisolone but not prednisolone 1

Treatment Approaches to Avoid as First-Line

• Combination of itraconazole and glucocorticoids is not recommended as first-line therapy for acute ABPA 1
  • However, a short course of glucocorticoids (<2 weeks) may be used initially along with oral itraconazole 1
• High-dose inhaled corticosteroids should not be used as primary therapy for acute ABPA 1
• Newer azoles (voriconazole, posaconazole, isavuconazole) should not be used as first-line agents 1
  • These may be considered if there are contraindications to systemic glucocorticoids or intolerance/failure/resistance to itraconazole 1
• Biological agents are not recommended as first-line therapy for acute ABPA 1
• Nebulized amphotericin B has poor efficacy in acute ABPA 1

Management of ABPA Exacerbations

• ABPA exacerbations occur in approximately 50% of patients after treatment cessation 1
• Exacerbations are characterized by:
  • Sustained worsening (≥2 weeks) of clinical symptoms or new infiltrates on chest imaging
  • Increase in serum total IgE by ≥50% above the "new baseline" IgE during clinical stability 1
• Treat acute ABPA exacerbations in the same manner as newly diagnosed ABPA (oral prednisolone or itraconazole) 1
• For recurrent exacerbations (≥2 in the last 1-2 years), especially in patients with extensive bronchiectasis, use a combination of oral prednisolone and itraconazole 1
• Biological agents and nebulized amphotericin B are not recommended for treating acute ABPA exacerbations 1

Monitoring Treatment Response

• Monitor response after 8-12 weeks using:
  • Clinical symptoms (using a semiquantitative Likert scale)
  • Serum total IgE levels
  • Chest radiographs 1
• A good response is indicated by:
  • Significant improvement in symptoms (≥50% improvement on Likert scale)
  • Improvement on imaging
  • At least a 20% reduction in serum total IgE levels 1

Special Considerations

• Differentiate between ABPA exacerbations, asthma exacerbations, and infective exacerbations of bronchiectasis using chest radiographs, serum total IgE, and sputum bacterial cultures 1
• Patients with blood eosinophil count ≥1000 cells/μL and extensive bronchiectasis (≥10 segments) may benefit from combination therapy with prednisolone and itraconazole 1
• Early diagnosis and treatment is essential to prevent permanent airway damage and bronchiectasis 2