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

ISHAM Guidelines for Allergic Bronchopulmonary Aspergillosis (ABPA) Treatment

The European Respiratory Society recommends treating acute ABPA with either oral prednisolone (0.5 mg/kg/day for 2-4 weeks, tapered over 4 months) or oral itraconazole for 4 months as first-line therapy, with treatment decisions based on ABPA classification and symptom severity. 1, 2, 3

Classification and Initial Treatment Approach

• ABPA should be classified as either ABPA with bronchiectasis (ABPA-B) or ABPA without bronchiectasis (ABPA-S) to guide treatment decisions 2
• Asymptomatic ABPA patients should not receive systemic therapy 1, 2, 3
• 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, 2, 3

First-Line Treatment Options for Acute ABPA

• Oral prednisolone at 0.5 mg/kg/day for 2-4 weeks, tapered and completed over 4 months is recommended as first-line therapy 1, 2, 3
• Oral itraconazole (400 mg/day in two divided doses) for 4 months is an alternative first-line option, especially when systemic glucocorticoids are contraindicated 1, 2, 3
• Therapeutic drug monitoring for itraconazole is recommended with a target trough level ≥0.5 mg/L 3
• Combination of itraconazole and glucocorticoids is not recommended as first-line therapy, though a short course of glucocorticoids (<2 weeks) may be used initially with oral itraconazole 1, 3

Treatment Contraindications and Cautions

• High-dose inhaled corticosteroids (ICS) alone should not be used as primary therapy for acute ABPA 1
• Biological agents are not recommended as first-line therapy for acute ABPA 1, 3
• Oral voriconazole, posaconazole, and isavuconazole should not be used as first-line agents but may be considered if there are contraindications to systemic glucocorticoids and intolerance, failure, or resistance to itraconazole therapy 1
• Vitamin D deficiency should be corrected as it can aggravate osteopenia due to long-term glucocorticoid usage 1

Management of ABPA Exacerbations

• ABPA exacerbations occur in approximately 50% of patients after treatment cessation 1, 2
• ABPA exacerbations are characterized by sustained worsening (≥2 weeks) of clinical symptoms or new infiltrates on chest imaging, along with an increase in serum total IgE by ≥50% above the "new baseline" IgE 1, 2, 3
• ABPA exacerbations should be treated like newly diagnosed ABPA using either prednisolone or itraconazole 1, 3
• Combination therapy with oral prednisolone and itraconazole should be considered for patients with recurrent exacerbations (≥2 in the last 1-2 years), especially in those with extensive bronchiectasis 1, 2, 3

Monitoring Treatment Response

• Response to treatment should be assessed after 8-12 weeks using clinical symptoms, serum total IgE levels, and chest radiographs 2, 3
• A good response is defined as significant improvement in symptoms (≥50% improvement on Likert scale), improvement on imaging, and at least a 20% reduction in serum total IgE levels 2
• Continued monitoring with clinical review, serum total IgE levels, and lung function tests every 3-6 months is recommended 3

Special Considerations

• It's important to differentiate between ABPA exacerbations, asthma exacerbations, and infective exacerbations of bronchiectasis using chest radiographs, serum total IgE, and sputum bacterial cultures 1, 2
• Patients with blood eosinophil count ≥1000 cells/μL and extensive bronchiectasis (≥10 segments) may benefit from combination therapy 3
• Liver function tests should be performed monthly in patients on itraconazole 3
• Methylprednisolone should not be used with itraconazole due to higher risk of Cushing's syndrome 3
• Omalizumab may be considered for treatment-dependent ABPA (patients who continue to have symptoms despite conventional therapy) 3