Management of Acute Allergic Bronchopulmonary Aspergillosis (ABPA)

Initial First‑Line Therapy

• For newly diagnosed acute ABPA, either oral prednisolone 0.5 mg/kg/day for 2–4 weeks followed by a taper to complete a 4‑month course, or oral itraconazole 400 mg/day (divided twice daily) for 4 months is recommended by the European Respiratory Society (ERS) guideline. 1

• The prednisolone regimen (0.5 mg/kg/day for 2–4 weeks, then gradual taper to a total of 4 months) is endorsed as a primary monotherapy option. 2

• The itraconazole regimen (400 mg/day in two divided doses with meals for 4 months) is endorsed as an alternative first‑line monotherapy, particularly when systemic glucocorticoids are contraindicated. 3

Critical Drug‑Interaction Warning

• Co‑administration of systemic corticosteroids (e.g., methylprednisolone) with itraconazole should be avoided because it markedly increases the risk of exogenous Cushing’s syndrome and adrenal insufficiency, according to the ERS guideline. 1
• High‑dose inhaled corticosteroids (e.g., budesonide or fluticasone) should also not be combined with itraconazole due to cytochrome P450 inhibition that can cause adrenal suppression. 2

Use of Combination Therapy

• Combination therapy (prednisolone + itraconazole) is not recommended as first‑line treatment for acute ABPA. 3

• Combination therapy may be considered in patients who have any of the following:

• When initiating itraconazole, a short (< 2‑week) course of oral glucocorticoids can be added to achieve rapid symptom control, after which treatment can be transitioned to high‑dose inhaled corticosteroids once symptoms improve. 2

Management According to ABPA Classification

• Asymptomatic ABPA: No systemic therapy is advised; management focuses on optimizing asthma control with high‑dose inhaled corticosteroids and periodic monitoring (clinical review, chest radiograph, serum total IgE every 3–6 months). 3

• Serological ABPA without bronchiectasis (ABPA‑S): Treat as asthma with standard inhaled therapies; systemic ABPA‑directed therapy is reserved for patients with poor asthma control despite optimal management or recurrent exacerbations despite appropriate therapy. 3

• Acute ABPA with bronchiectasis or mucus plugging: Systemic treatment (prednisolone or itraconazole as described above) is required even if the patient is otherwise asymptomatic, to prevent progression to irreversible bronchiectasis. 2

Definition and Management of ABPA Exacerbations

• An ABPA exacerbation is defined by all of the following:

• Exacerbations are distinguished from pure asthma exacerbations (no IgE rise, no new infiltrates) and from bronchiectasis infective exacerbations (no IgE rise, positive sputum cultures). 4

• Treatment of an ABPA exacerbation mirrors that of newly diagnosed disease: use either prednisolone monotherapy or itraconazole monotherapy. 4

• For patients with recurrent exacerbations (≥ 2 in 1–2 years), especially those with extensive bronchiectasis, combination therapy with prednisolone + itraconazole is recommended. 4

Second‑Line Antifungal Options

• Voriconazole, posaconazole, and isavuconazole are not first‑line agents; they should be reserved for patients who cannot receive systemic glucocorticoids or who have intolerance, failure, or resistance to itraconazole. 3

Monitoring Treatment Response

• Response should be assessed at 8–12 weeks after therapy initiation using the following criteria (ERS guideline):

• Ongoing monitoring is advised every 3–6 months with clinical review, serum IgE measurement, lung‑function testing, and chest imaging as clinically indicated.

Steroid‑Sparing and Adjunctive Therapies

• Biological agents (omalizumab or dupilumab) are not first‑line but may be employed as steroid‑sparing options in patients who are treatment‑dependent or experience frequent exacerbations. 3

• High‑dose inhaled corticosteroids alone do not achieve immunological control or reduce ABPA exacerbations when used as primary therapy. 3

• Nebulized amphotericin B has poor efficacy for both acute ABPA and ABPA exacerbations and should be avoided. 4

Relapse After Treatment Cessation

• Approximately 50 % of patients experience ABPA exacerbations after discontinuation of therapy, necessitating retreatment. This relapse rate is highlighted in the ERS guideline. 4

Treatment of Allergic Bronchopulmonary Aspergillosis (ABPA)

Introduction to ABPA Treatment

• The European Respiratory Society recommends the first-line treatment for acute Allergic Bronchopulmonary Aspergillosis (ABPA) to be either oral prednisolone (0.5 mg/kg/day for 2-4 weeks, then tapered over 4 months) or oral itraconazole for 4 months 5, 6

Treatment Algorithm Based on ABPA Classification

• For asymptomatic ABPA patients, systemic therapy is not recommended, according to the European Respiratory Society 5, 6
• The European Respiratory Society suggests managing ABPA-S (serological ABPA without bronchiectasis) like asthma with appropriate asthma medications, and using systemic therapy only if there is poor asthma control or recurrent exacerbations despite optimal asthma management 5, 6, 7

Acute ABPA Treatment Options

• The European Respiratory Society recommends oral prednisolone (0.5 mg/kg/day for 2-4 weeks, then tapered and completed over 4 months) as a first-line option for acute ABPA treatment 5, 6
• The European Respiratory Society also recommends oral itraconazole (400 mg/day in two divided doses for 4 months) as a first-line option, especially when systemic glucocorticoids are contraindicated, with therapeutic drug monitoring (target trough level ≥0.5 mg/L) 5, 6, 8
• Combination of itraconazole and glucocorticoids is not recommended as first-line therapy by the European Respiratory Society, but a short course of glucocorticoids (<2 weeks) may be used initially with oral itraconazole 5, 6

Management of ABPA Exacerbations

• The European Respiratory Society suggests treating ABPA exacerbations the same way as newly diagnosed ABPA, and using a combination of oral prednisolone and itraconazole for recurrent exacerbations (≥2 in the last 1-2 years), especially in patients with extensive bronchiectasis 5, 6, 8

Monitoring Treatment Response

• The European Respiratory Society recommends assessing response after 8-12 weeks using clinical symptoms, serum total IgE levels (should decrease by ≥35% from baseline), and chest radiographs 5, 6, 8
• Continued monitoring with clinical review, serum total IgE levels, and lung function tests every 3-6 months is suggested by the European Respiratory Society 8, 9

Special Considerations

• Patients with blood eosinophil count ≥1000 cells/μL and extensive bronchiectasis (≥10 segments) may benefit from combination therapy, according to the European Respiratory Society 7
• Liver function tests should be performed monthly in patients on itraconazole, as recommended by the European Respiratory Society 8
• Methylprednisolone should not be used with itraconazole due to higher risk of Cushing's syndrome, according to the European Respiratory Society 8

Role of Biological Agents

• Omalizumab may be considered for treatment-dependent ABPA (patients who continue to have symptoms despite conventional therapy) by the European Respiratory Society 9
• Biological agents are not first-line treatments but may be options for steroid-dependent patients, according to the European Respiratory Society 9

Duration of Dupilumab Treatment for ABPA

Treatment Algorithm for ABPA

• The European Respiratory Society recommends initial treatment duration for both oral glucocorticoids and itraconazole to be 4 months for newly diagnosed acute ABPA 10, 11
• Response to treatment should be assessed after 8-12 weeks using clinical symptoms, serum total IgE levels, and chest radiographs, as recommended by the European Respiratory Society 11

Treatment-Dependent ABPA

• Approximately 10-25% of ABPA patients become treatment-dependent, requiring ongoing therapy, according to the European Respiratory Society 12, 11
• For treatment-dependent ABPA, biological agents including dupilumab are recommended options by the European Respiratory Society 12, 11

Dupilumab in ABPA Management

Duration of Treatment

• There is no established fixed duration of treatment with dupilumab for ABPA in current guidelines from the European Respiratory Society 10, 12, 11

Monitoring During Dupilumab Treatment

• A good response to dupilumab treatment is indicated by major improvement in symptoms and chest radiographs, along with at least a 20% reduction in serum total IgE, as suggested by the European Respiratory Society 11

Guideline for Oral Prednisolone and Antifungal Management of Adult ABPA

Initial Prednisolone Dosing

• For a 70 kg adult, prescribe prednisolone 35 mg (0.5 mg/kg) orally once daily for 2–4 weeks; the dose should be taken in the morning with food to reduce gastric irritation【13】.

Tapering Strategies (British Thoracic Society & European Respiratory Society)

• Option 1 – Shorter taper (recommended for most patients):
  
  • Weeks 1‑2: 0.5 mg/kg/day (≈35 mg daily)【14】.
  • Weeks 3‑10: Alternate‑day dosing at the same total weekly dose (≈35 mg every other day)【15】【14】.
  • Weeks 11‑16: Reduce by 5–10 mg every 2 weeks until discontinuation【15】【14】.
  • Total treatment duration: 3–5 months【15】【13】.
• Option 2 – Prolonged taper (severe disease or extensive bronchiectasis):
  
  • Weeks 1‑6: 0.75 mg/kg/day (≈50 mg daily)【15】.
  • Weeks 7‑12: Reduce to 0.5 mg/kg/day (≈35 mg daily)【15】.
  • Weeks 13 and beyond: Decrease by 5 mg every 6 weeks, aiming for a total course of 6–12 months【15】.

Monitoring During Steroid Therapy

• Check serum total IgE every 6–8 weeks; a ≥35 % reduction from baseline indicates good response, while a ≥50 % rise above the stable baseline suggests exacerbation【15】【14】.
• Track peripheral blood eosinophil count alongside IgE levels【14】.
• If IgE plateaus or rises during taper, slow the taper or briefly increase the dose before resuming a gradual reduction【15】【14】.

Definition of Remission

• Remission is achieved when the patient remains free of pulmonary infiltrates and eosinophilia for at least 6 months after complete steroid withdrawal【15】【14】.

Steroid‑Related Adverse‑Effect Monitoring

• Metabolic: monitor blood pressure and fasting glucose regularly for hyperglycemia, weight gain, and hypertension【13】.
• Bone health: prescribe calcium 1000–1500 mg/day and vitamin D 800–1000 IU/day from day 1 of therapy【13】.
• Other: watch for Cushingoid features, mood changes, gastritis, cataracts, and opportunistic infections【13】.

Alternative First‑Line Antifungal Therapy (When Steroids Contraindicated)

• Itraconazole 400 mg/day (200 mg twice daily with meals) for 4 months【13】.
• Use conventional itraconazole capsules (200 mg twice daily with meals) to improve absorption【13】.
• Perform therapeutic drug monitoring after 2 weeks; target trough ≥0.5 mg/L (ideal 1–2 mg/L)【13】.
• Monitor liver function tests monthly due to hepatotoxicity risk【13】.
• Maximum dose may be increased to 600 mg/day if needed【13】.

Critical Drug‑Interaction Warning

• Do not combine itraconazole with methylprednisolone, as this markedly raises the risk of exogenous Cushing’s syndrome and adrenal insufficiency【13】.
• Itraconazole does not significantly affect prednisolone levels, making prednisolone the preferred corticosteroid when combination therapy is required【13】.

Indications for Adding Itraconazole to Prednisolone (Combination Therapy)

• Steroid‑dependent disease characterized by difficulty weaning from corticosteroids or relapse upon dose reduction【15】【14】.

Second‑Line Antifungal Options (Reserved for Itraconazole Failure or Intolerance)

These agents are not first‑line and should be used only in specific circumstances【13】.

Role of Inhaled Corticosteroids

• High‑dose inhaled corticosteroids alone do not control ABPA and should not be used as primary therapy【15】【14】.
• They may be employed as an adjunct to oral steroids for improved asthma symptom control【15】【14】.

Steroid‑Sparing Biological Agents (For Treatment‑Dependent ABPA)

• Omalizumab: dose based on body weight and serum IgE, not exceeding 375 mg subcutaneously twice monthly【13】.
• Mepolizumab: 100 mg subcutaneously monthly【13】.
• Dupilumab: 600 mg loading dose subcutaneously, then 300 mg every 2 weeks【13】.
• Biologics are not first‑line but may be considered when conventional therapy cannot be discontinued without relapse【13】.

Common Pitfalls to Avoid

• Tapering too quickly leads to relapse; reduce the dose by 5 mg increments every 2–6 weeks【15】【14】.
• Ignoring rising IgE trends during taper signals impending exacerbation; slow or reverse the taper accordingly【15】【14】.
• Using methylprednisolone with itraconazole precipitates severe Cushing’s syndrome; prefer prednisolone when combination therapy is needed【13】.
• Neglecting bone protection: always prescribe calcium and vitamin D at steroid initiation【13】.

Guideline Recommendations for Management of Allergic Bronchopulmonary Aspergillosis (ABPA)

1. Diagnosis, Classification, and Monitoring

• Asymptomatic ABPA should not receive systemic therapy; instead, patients are monitored with clinical review, chest radiograph, and serum total IgE every 3–6 months. (European Respiratory Society) 16
• Serological ABPA without bronchiectasis (ABPA‑S) is managed as standard asthma using high‑dose inhaled corticosteroids (ICS) and bronchodilators; systemic steroids or antifungals are reserved for poor asthma control or recurrent exacerbations. (European Respiratory Society) 16
• High‑dose ICS alone does not achieve immunological control or reduce ABPA exacerbations and should never be used as primary ABPA therapy. (European Respiratory Society) 16

2. First‑Line Acute Treatment

• Oral prednisolone 0.5 mg/kg/day for 2–4 weeks, followed by a taper over a total of 4 months, is a first‑line monotherapy for acute ABPA. (European Respiratory Society) 16
• Oral itraconazole 400 mg/day (divided twice daily with meals) for 4 months is an alternative first‑line monotherapy when steroids are contraindicated. (European Respiratory Society) 16

3. Critical Drug‑Interaction Warning

• Co‑administration of itraconazole with methylprednisolone markedly increases the risk of exogenous Cushing’s syndrome and adrenal insufficiency; prednisolone should be used instead. (European Respiratory Society) 16

4. Combination Therapy (Prednisolone + Itraconazole)

• Combination therapy is not recommended as first‑line treatment. (European Respiratory Society) 16
• A short course (< 2 weeks) of oral glucocorticoids may be added when initiating itraconazole to achieve rapid symptom control, after which high‑dose inhaled corticosteroids can be continued. (European Respiratory Society) 16
• Indications for combination therapy include ≥ 2 ABPA exacerbations in the previous 1–2 years. (European Respiratory Society) 16

5. Assessment of Treatment Response

• Response should be evaluated at 8–12 weeks using the following criteria:
  
  • Clinical improvement ≥ 50 % reduction in symptom score.
  • Serum total IgE reduction ≥ 20 % from baseline (≥ 35 % preferred).
  • Resolution of infiltrates on chest imaging.
  • Spirometric improvement in FEV₁ ≥ 158 mL (minimal clinically important difference).
    (All criteria endorsed by the European Respiratory Society) 16
• After initial assessment, patients are monitored every 3–6 months with clinical review, serum IgE, lung‑function testing, and imaging as needed. (European Respiratory Society) 16

6. Definition and Management of Exacerbations

• An ABPA exacerbation requires all three of the following:
  (European Respiratory Society) 16

• Exacerbation types and treatment:

  • Asthma exacerbation – no IgE rise, no new infiltrates; treat with a short‑course oral glucocorticoid. (European Respiratory Society) 16
  • Bronchiectasis infective exacerbation – no IgE rise, positive sputum cultures; treat with appropriate antibiotics. (European Respiratory Society) 16
  • ABPA exacerbation – IgE rise ≥ 50 % plus new infiltrates; treat as newly diagnosed acute ABPA with either prednisolone or itraconazole monotherapy. (European Respiratory Society) 16
• Recurrent exacerbations (≥ 2 in 1–2 years), especially with extensive bronchiectasis, warrant combination therapy (prednisolone + itraconazole). (European Respiratory Society) 16
• Approximately 50 % of patients experience an exacerbation after treatment cessation, often requiring retreatment. (European Respiratory Society) 16

7. Second‑Line Antifungal Options

• Voriconazole, posaconazole, and isavuconazole are not first‑line agents; they are reserved for patients who cannot receive systemic glucocorticoids or who have intolerance, failure, or resistance to itraconazole. (European Respiratory Society) 16

(European Respiratory Society) 16

8. Role of Biological Agents

• Biological agents (omalizumab, mepolizumab, dupilumab) are not first‑line therapy; they may be considered for treatment‑dependent ABPA (patients requiring ongoing therapy after the initial 4‑month course or who relapse upon dose reduction). (European Respiratory Society) 16

9. Common Pitfalls to Avoid

• Using methylprednisolone with itraconazole can precipitate severe Cushing’s syndrome; prednisolone should be used instead. (European Respiratory Society) 16
• High‑dose inhaled corticosteroids alone should never be used as primary ABPA therapy because they do not control disease immunologically. (European Respiratory Society) 16
• Failure to differentiate between asthma, ABPA, and infective bronchiectasis exacerbations (by assessing IgE trends, imaging, and sputum cultures) can lead to inappropriate treatment. (European Respiratory Society) 16