Allergic Bronchopulmonary Aspergillosis

KEY FEATURES

• A bronchopulmonary hypersensitivity disorder caused by allergy to fungal antigens

• Usually occurs in response to antigens of Aspergillus species in atopic asthmatic individuals or those with cystic fibrosis

CLINICAL FINDINGS

• Symptoms

  • Dyspnea

  • Wheezing

  • Cough

• Relapses after therapy are common

• Complications

  • Hemoptysis

  • Severe bronchiectasis

  • Pulmonary fibrosis

DIAGNOSIS

• Primary criteria

  • Clinical history of asthma or cystic fibrosis

  • Elevated serum total IgE levels (typically > 1000 IU/mL; a value < 1000 IU/mL may be accepted if all other criteria are met

  • Immediate cutaneous hypersensitivity to Aspergillus antigens or elevated serum IgE levels specific to A fumigatus

  • At least two of the following:

    • Precipitating serum antibodies to Aspergillus antigen or elevated serum Aspergillus IgG by immunoassay

    • Radiographic pulmonary abnormalities consistent with ABPA

    • Peripheral blood eosinophil count > 500 cells/mcL (0.5 × 10⁹/L)

• Radiographic abnormalities include

  • Transient opacities

  • Mucoid impaction

  • Proximal or central bronchiectasis

TREATMENT

• High-dose corticosteroids (eg, prednisone 0.5–1 mg/kg orally per day) for at least 2 weeks with gradual taper is the treatment of choice

• Patients with corticosteroid-dependent disease may benefit from itraconazole or voriconazole

• Relapses are frequent

• For those who have frequent exacerbations or who are unable to wean off corticosteroids, the use of biologic agents (eg, anti-IgE [omalizumab], anti-interleukin [IL]-5 [mepolizumab, benralizumab], or anti-IL4 receptor [dupilumab]), has been shown to improve outcomes

• Bronchodilators may also be helpful