Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a common complication of cystic fibrosis (CF), occurring in similar to10% of patients and accompanying/accounting for similar to10% of pulmonary exacerbations. ABPA pathogenesis is dependent upon impaired clearance and dense respiratory epithelial exposure to A. fumigatus (Af) spores with subsequent chemotactic recruitment of CD4+ Th2 lymphocytes specific for Af to lung tissue. Susceptibility to ABPA appears to involve risk factors including atopy and defined major histocompatibility complex-restricted alleles. Distinct cytoplasmic Af molecules (Af2, 4, and 6), now available as recombinant allergen reagents, appear to be associated with ABPA. Minimal criteria for diagnosis of ABPA in CF include clinical deterioration, elevated total serum IgE, positive immediate Af skin test or serum IgE antibodies, and Af serum precipitins/IgG antibodies or radiographic changes. Annual screening of total serum IgE is recommended from age 6 yr. Systemic glucocorticosteroids remain the mainstay of treatment. Itraconazole has an established role as a steroid-sparing agent if the patient has a slow or poor response to steroids, relapses, or is at risk for or develops steroid toxicity. Monitoring of clinical, radiographic and laboratory responses (especially total serum IgE) is essential.