What is the treatment for Allergic Bronchopulmonary Aspergillosis (ABPA)?

Treatment of Allergic Bronchopulmonary Aspergillosis (ABPA)

The first-line treatment for acute Allergic Bronchopulmonary Aspergillosis (ABPA) is either oral prednisolone (0.5 mg/kg/day for 2-4 weeks, then tapered over 4 months) or oral itraconazole for 4 months. 1, 2

Treatment Algorithm Based on ABPA Classification

• Asymptomatic ABPA: Systemic therapy is not recommended 1, 2
• ABPA-S (Serological ABPA): Manage like asthma with appropriate asthma medications; use systemic therapy only if poor asthma control or recurrent exacerbations despite optimal asthma management 1, 2
• ABPA with bronchiectasis (ABPA-B): Requires systemic therapy with either glucocorticoids or antifungals 1, 2
• ABPA with mucus plugging (ABPA-MP) or high-attenuation mucus (ABPA-HAM): Requires systemic therapy similar to ABPA-B 1
• ABPA with chronic pleuropulmonary fibrosis (ABPA-CPF): Requires more aggressive management with possible combination therapy 1

First-Line Treatment Options for Acute ABPA

Oral Glucocorticoids

• Low-to-moderate dose oral prednisolone: 0.5 mg/kg/day for 2-4 weeks, then tapered and completed over 4 months 1, 2
• Provides effective control of immune responses against Aspergillus antigens 1, 3
• Lower doses have fewer adverse events compared to higher doses while maintaining similar efficacy in preventing exacerbations 1

Oral Antifungals

• Itraconazole: 400 mg/day in two divided doses for 4 months 2
• Recommended as first-line therapy when systemic glucocorticoids are contraindicated 1
• Requires therapeutic drug monitoring with target trough level ≥0.5 mg/L 2
• Decreases airway fungal colonization 1

Important Cautions

• Combination of itraconazole and glucocorticoids is not recommended as first-line therapy 1
• Short course of glucocorticoids (<2 weeks) may be used initially with oral itraconazole if needed 1
• Care should be taken when using methylprednisolone with itraconazole due to higher risk of exogenous Cushing's syndrome 1, 2
• High-dose inhaled corticosteroids (ICS) alone should not be used as primary therapy for acute ABPA 1, 4

Management of ABPA Exacerbations

• ABPA exacerbations are characterized by worsening clinical symptoms for ≥2 weeks, new infiltrates on chest imaging, and increase in serum total IgE by ≥50% above baseline 1
• Treat exacerbations the same way as newly diagnosed ABPA with either prednisolone or itraconazole 1
• Consider combination of oral prednisolone and itraconazole for recurrent exacerbations (≥2 in 1-2 years), especially in patients with extensive bronchiectasis 1, 2
• Differentiate between ABPA exacerbation, asthma exacerbation, and infective bronchiectasis exacerbation 1

Monitoring Treatment Response

• Assess response after 8-12 weeks using:
  • Clinical symptoms improvement
  • Serum total IgE levels (should decrease by ≥35% from baseline)
  • Chest radiographs 2
• Continue monitoring with clinical review, serum total IgE levels, and lung function tests every 3-6 months 2
• Liver function tests should be performed monthly in patients on itraconazole 2

Special Considerations

• Patients with blood eosinophil count ≥1000 cells/μL and extensive bronchiectasis (≥10 segments) may benefit from combination therapy 2
• Second-line antifungals (voriconazole, posaconazole, isavuconazole) may be used if there are contraindications to systemic glucocorticoids and intolerance, failure, or resistance to itraconazole therapy 1
• Biological agents (e.g., omalizumab) are not first-line treatments but may be options for steroid-dependent patients 1, 2
• Early diagnosis and treatment are essential to prevent progression to fibrotic lung disease 3

Common Pitfalls and Caveats

• Failing to differentiate between asthma exacerbation and ABPA exacerbation 1
• Using high-dose ICS alone for ABPA treatment, which has been shown to be ineffective 1, 4
• Not monitoring for drug interactions between azoles and corticosteroids 1, 2
• Combination of inhaled budesonide or fluticasone and itraconazole can cause exogenous Cushing's syndrome 1
• Delaying treatment in symptomatic patients, which can lead to irreversible lung damage 3