Background: Aspergillus fumigatus (Af) sensitization and persistent carriage are deleterious to lung function, but no consensus has been reached defining these medical entities. This work aimed to identify possible predictive factors for patients who become sensitized to Af, compared to a control group of non-sensitized Af carriers.
Methods: Between 1995 and 2007, 117 pediatric patients were evaluated. Demographic data, CFTR gene mutations, BMI, and FEV1 were recorded. The presence of Af in sputum, the levels of Af-precipitin, total IgE (t-IgE), and specific IgE to Af (Af-IgE) were determined. Patients were divided into 2 groups: (1) "sensitization": level of Af-IgE > 0.35 IU/mL with t-IgE level < 500 IU/mL, and (2) "persistent or transient carriage": Af-IgE level <= 0.35 IU/mL with either an Af transient or persistent positive culture. A survival analysis was performed with the appearance of Af-IgE in serum as an outcome variable.
Results: Severe mutation (HR=3.2), FEV1 baseline over 70% of theoretical value (HR=4.9), absence of Pa colonization, catalase activity and previous azithromycin administration (HR=9.8, HR=4.1, HR=1.9, respectively) were predictive factors for sensitization. We propose a timeline of the biological events and a tree diagram for risk calculation.
Conclusion: Two profiles of CF patients can be envisaged: (1) patients with non-severe mutation but low FEV1 baselines are becoming colonized with Af or (2) patients with high FEV1 baselines who present with severe mutation are more susceptible to the Af sensitization then to the presentation of an ABPA event.
(C) 2014 by Lippincott Williams & Wilkins, Inc.