Allergic bronchopulmonary aspergillosis

ABPA is a hypersensitivity reaction to the opportunistic mold Aspergillus, most commonly Aspergillus fumigatus.

The pathophysiology of ABPA involves a dominant Th2 immune response to antigens derived from Aspergillus fumigatus. The disease is characterized by marked local and systemic eosinophilia, an adaptive immune response with elevated levels of Aspergillus fumigatus-specific IgG, IgA, and IgE antibodies, and a profound nonspecific IL-4-dependent elevation in total IgE.

The prevalence of ABPA is estimated at around 2.5% in adult patients with asthma. The incidence of ABPA in Spain is estimated at 126 per 100,000 person-years.

The main risk factors for developing ABPA are having asthma or cystic fibrosis. Less common risk factors include other lung diseases associated with immunocompromise, such as tuberculosis, chronic granulomatous disease, and hyper-IgE syndrome.

Clinically, ABPA manifests with recurring episodes of asthma, pulmonary infiltrates, and central bronchiectasis. It may progress to fibrosis if not properly managed.

The prognosis of ABPA is largely dependent on the severity of the disease and the patient's response to treatment. While some patients may experience a complete resolution of symptoms with appropriate treatment, others may have recurrent exacerbations or progress to more severe forms of the disease.