Allergic Bronchopulmonary Aspergillosis (ABPA) for Expert Patients and non-Specialist Clinicians

Expert Information for Patients, GPs, and Specialist Nurses

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🔎 What Is ABPA?

ABPA is a complex hypersensitivity reaction to Aspergillus fumigatus colonising the airways. It is not a fungal infection in the classic sense, but rather an exaggerated immune response — particularly involving IgE and eosinophils — seen in people with asthma or cystic fibrosis (CF).

It leads to recurrent inflammation, mucus plugging, and bronchial damage (including central bronchiectasis) if untreated.

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🧬 Disease Mechanism

• Type I and III hypersensitivity to A. fumigatus

• Chronic airway inflammation causes mucus impaction and permanent lung damage

• Associated with elevated total and specific IgE, eosinophilia, and recurrent flares

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👥 Who Is at Risk?

• Moderate to severe asthma

• Cystic fibrosis

• Rarely, patients with bronchiectasis or other chronic airway disease

ABPA is often underdiagnosed, especially in adults with difficult-to-control asthma.

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⚠️ Common Symptoms

• Worsening asthma control

• Wheeze and chest tightness

• Cough with thick mucus plugs

• Shortness of breath

• Intermittent low-grade fever

• Haemoptysis (less common, usually mild)

• Fatigue and poor response to inhaled steroids alone

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🧪 Diagnosis

Diagnosis is based on a combination of clinical, radiological, and immunological features.

Core Investigations:

1. Total IgE ≥1000 IU/mL (or >500 in treated patients)

2. Aspergillus-specific IgE positive

3. Aspergillus-specific IgG (or precipitating antibodies)

4. Blood eosinophilia (>0.5 x10⁹/L typically)

5. Chest CT: central bronchiectasis, mucus plugging (“finger-in-glove”), fleeting infiltrates

6. Sputum culture or PCR positive for A. fumigatus

Diagnostic Criteria:

Use updated ISHAM criteria (2024 version preferred) combining major and minor features.

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💊 Treatment

First-Line:

• Oral corticosteroids (e.g. prednisolone) – cornerstone of flare management

  • Typically tapered over 3–6 months

Adjunct:

• Itraconazole or posaconazole – reduces antigen burden and steroid need

  • 3–6 months or longer; monitor liver function and drug levels

Steroid-Sparing Options:

• Biologics (increasingly used, especially in steroid-dependent or relapsing patients):

  • Omalizumab (anti-IgE)

  • Mepolizumab, Benralizumab (anti-IL-5)

  • Dupilumab, Tezepelumab (emerging options)

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🧾 Monitoring

• Total IgE every 1–3 months (a 25–50% rise may indicate relapse)

• Pulmonary function tests (FEV1, peak flow)

• Repeat CT if clinical deterioration or poor steroid response

• Sputum cultures in persistent symptoms (to exclude Aspergillus bronchitis)

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⚠️ Complications

• Progression to bronchiectasis

• CPA (if antifungals are stopped prematurely in chronic cases)

• Recurrent flares leading to irreversible damage

• Steroid side effects (weight gain, osteoporosis, adrenal suppression)

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📚 More Information

• Specialist referral: patients should be considered for referral to the National Aspergillosis Centre (NAC) or local respiratory immunology team for persistent/recurrent ABPA.

• Patient support: aspergillosis.org, CF Trust, Asthma + Lung UK

• Key guidelines: Guidance

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