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 with a control group of non-sensitized Af carriers.
Methods: Between 1995 and 2007, 117 pediatric patients were evaluated. Demographic data, CFTR gene mutations, body mass index 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 (hazard ratio = 3.2), FEV1 baseline over 70% of theoretical value (hazard ratio = 4.9), absence of Pa colonization, catalase activity and previous azithromycin administration (hazard ratio = 9.8, 4.1 and 1.9, respectively) were predictive factors for sensitization. We propose a timeline of the biological events and a tree diagram for risk calculation.
Conclusions: Two profiles of cystic fibrosis patients can be envisaged: (1) patients with nonsevere 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 and then to the presentation of an allergic bronchopulmonary aspergillosis event.
From the *Service de Parasitologie—Mycologie, IFB, Hôpital Purpan; †UMR152, Université Toulouse III; ‡Service de Pneumologie Allergologie, Hôpital des Enfants; §Centre de Ressources et de Compétence pour la Mucoviscidose (CRCM) enfant et adulte; ¶Service de Pneumologie Allergologie, Hôpital Larrey; and ‖Laboratoire de Bactériologie—Hygiène, Hôpital Purpan, Toulouse, France.
Accepted for publication December 3, 2013.
J.F. and S.C. are members of the ISHAM Working Group investigating “Fungal respiratory infection in cystic fibrosis”. F.B. and M.M. are the heads of the Toulouse Cystic Fibrosis Resources and Competence Centre for paediatric and adult cystic fibrosis patients, respectively.
The authors have no conflicts of interest or funding to disclose.
Address for correspondence: Judith Fillaux, MD, PhD, Service de Parasitologie— Mycologie, IFB, Hôpital Purpan, 31059 Toulouse, France. E-mail: email@example.com.