Corticosteroid treatment is associated with increased filamentous fungal burden in
allergic fungal disease

Fraczek, MG; Chishimba, L; Niven, RM; Bromley, M; Simpson, A; Smyth, LJC; Denning, DW; Bowyer, P

Abstract

Background
Allergic diseases caused by fungi are common. The best understood conditions are allergic
bronchopulmonaryaspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS).
Our knowledge of the fungal microbiome (mycobiome) is limited to a few studies involving
healthy individuals, asthmatics and smokers. No study has yet examined the mycobiome in
fungal lung disease.
Objectives
The main aim of this study was to determine the mycobiome in lungs of individuals with well
characterised fungal disease. A secondary objective was to determine possible effects of
treatment on the mycobiome.
Methods
After bronchoscopy, ITS1 DNA was amplified and sequenced and fungal load determined by
RT-PCR. Clinical and treatment variables were correlated with the main species identified.
ABPA (n=16), SAFS (n=16), severe asthma not sensitised to fungi, (n=9), mild asthma
patients(n=7) and 10 healthy controls were studied.
Results
The mycobiome was highly varied with severe asthmatics carrying higher loads of fungus.
Healthy individuals had low fungal loads, mostly poorly characterised Malasezziales.The
most common fungus in asthmatics was Aspergillus fumigatus complex and this taxon
accounted for the increased burden of fungus in the high level samples. Corticosteroid
treatment was significantly associated with increased fungal load (p<0.01).
Conclusions
The mycobiome is highly variable. Highest loads of fungus are observed in severe asthmatics
and the most common fungus is Aspergillus fumigatus complex. Individuals receiving steroid
therapy had significantly higher levels of Aspergillus and total fungus in their BAL.

Citation

allergic fungal disease. Journal of Allergy and Clinical Immunology, 142(2), 407-414. https://doi.org/10.1016/j.jaci.2017.09.039

• Journal Article Type: Article
• Acceptance Date: Sep 21, 2017
• Online Publication Date: Nov 6, 2017
• Publication Date: Nov 6, 2017
• Deposit Date: Nov 29, 2017
• Publicly Available Date: Mar 27, 2018
• Journal: The Journal of Allergy and Clinical Immunology
• Print ISSN: 0091-6749
• Publisher: Elsevier
• Volume: 142
• Issue: 2
• Pages: 407-414
• DOI: https://doi.org/10.1016/j.jaci.2017.09.039
• Publisher URL: http://dx.doi.org/10.1016/j.jaci.2017.09.039
• Related Public URLs: http://www.jacionline.org/
• Additional Information: Projects : FP7-2007-2013; Grant Number: MR/M02010; Grant Number: HEALTH-F2-2010-260338 ''ALLFUN.''