Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology
Pulmonary Infiltrates with Eosinophilia (PIE) Syndromes are a heterogeneous group of lung diseases.
Pulmonary Infiltrates with Eosinophilia (PIE) (click to enlarge the image).
Allergic Bronchopulmonary Aspergillosis (ABPA)
There remains a lack of agreement on diagnostic criteria and approaches to treatment of patients with allergic bronchopulmonary aspergillosis (ABPA). http://buff.ly/1zJUpyk
ABPA occurs in patients with severe asthma who are often steroid-dependent. It occurs in 10% of patients with cystic fibrosis according to some studies ABPA is caused by the spores of Aspergillus fumigatus and is characterized by peripheral eosinophilia and high IgE (greater than 1,000 ng/mL (417 IU/ml)). ABPA is due to fungal colonization, not to local invasion.
T cell predominance in lung diseases:
CD8: hypersensitivity pneumonitis (HP) and COPD
Th2, CD4: Asthma, ABPA, pulmonary eosinophilia
Th1, CD4: granulomatous TB, sarcoid, berylliosis
Allergic Bronchopulmonary Aspergillosis (ABPA) (click to enlarge the image).
ABPA occurs in 1-2% of patients with asthma and 1-15% of patients with cystic fibrosis (CF).
Untreated ABPA rapidly progresses to severe central bronchiectasis and pulmonary fibrosis.
Diagnosis of ABPA
Essential diagnostic criteria for ABPA:
- high IgE (greater than 1,000 ng/mL (417 IU/ml))
- immediate skin test reactivity to A. fumigatus (skin prick test)
- elevated specific IgE to A. fumigatus
- chest CT with central bronchiectasis
Untreated ABPA evolves through 5 stages:
1. acute phase
4. steroid-dependent asthma
5. pulmonary fibrosis
ABPA treatment is with oral corticosteroids (CS) long term. The typical dose is daily prednisone at 0.5-1 mg/kg until there is a clinical improvement and a resolution of infiltrates on CXR.
The antifungal medication itraconazole can be also be helpful.
The treatment goal is to prevent the development or progression of bronchiectasis and worsening of pulmonary function.
Monitoring of ABPA therapy
Rising IgE levels can predict an ABPA recurrence. Doubling of the baseline IgE often indicates an ABPA exacerbation.
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Allergic Bronchopulmonary Aspergillosis. MK Cheezum, CJ Lettieri. Medscape Allergy & Clinical Immunology, 2008.
Allergic Bronchopulmonary Aspergillosis (ABPA). Russell Blair, MD; Jeremy S. Breit, MD; Stephen P. Peters, MD, PhD. Merck Manual, 2008
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