Effect of allergic bronchopulmonary aspergillosis on lung function in children with cystic fibrosis.
BACKGROUND
The relationship between sensitization to Aspergillus fumigatus and progression of pulmonary function is not yet established in cystic fibrosis (CF).


OBJECTIVE
We aimed to evaluate onset of A. fumigatus sensitization and development of allergic bronchopulmonary aspergillosis (ABPA), as well as to determine the physiologic factors of lung function influencing these mechanisms in CF.


METHODS
Serial annual lung function tests performed in 122 children with CF (62 males; 60 females; age: 6-18 yr) provided data pertaining to FRC measured by plethysmography, lung clearance index, volume of trapped gas, effective specific airway resistance, and forced expiratory indices (FEV1, FEF at 50% VC). Specific IgE to recombinant A. fumigatus allergens, rAspf1 and rAspf3, served as marker for sensitization, and to rAspf4 and rAspf6 as indications for a serologic ABPA, were clinically diagnosed (Nelson criteria). By linear mixed-effect model analysis, five patient groups, (1) not sensitized and free from Pseudomonas aeruginosa, (2) intermittently P. aeruginosa colonized, (3) chronically P. aeruginosa infected, (4) sensitized, and (5) with ABPA, were retrospectively evaluated.


RESULTS
A. fumigatus sensitization was best reflected by increased rAspf1+3-specific IgE levels, whereas, in most patients, sensitization was preceded by P. aeruginosa infection. Patients with ABPA demonstrated the most severe progression in all lung function parameters, and FEF at 50% VC, volume of trapped gas, and effective specific airway resistance were the best predictors (p < 0.0001). However, regarding distinction between sensitization to A. fumigatus and development of ABPA in the course of CF, chronic P. aeruginosa infection has to be taken into account.


CONCLUSIONS
Airway narrowing, gas trapping, and small airway disease are the major targets for functional derangement in ABPA.
Kraemer
Richard
R
Division of Human Genetics, Department of Paediatrics, University of Bern, Inselspital, CH-3010 Bern, Switzerland. richard.kraemer@insel.ch
Deloséa
Natascha
N
Ballinari
Pietro
P
Gallati
Sabina
S
Crameri
Reto
R
D000293:Adolescent; D000485:Allergens / Q000276:immunology; D052179:Antigens, Plant; D001229:Aspergillosis, Allergic Bronchopulmonary / Q000453:epidemiology* / Q000276:immunology / Q000503:physiopathology*; D002648:Child; D002908:Chronic Disease; D015897:Comorbidity; D003550:Cystic Fibrosis / Q000453:epidemiology* / Q000276:immunology / Q000503:physiopathology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics; D018450:Disease Progression; D005260:Female; D005656:Fungal Proteins / Q000276:immunology; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008297:Male; D011552:Pseudomonas Infections / Q000453:epidemiology; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
C081947:ASPF1 protein, Aspergillus fumigatus; D000485:Allergens; D052179:Antigens, Plant; C115315:Asp f 3 allergen; C505032:CFTR protein, human; D005656:Fungal Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator