Int J Biochem Cell Biol. 2014 Mar 10. pii: S1357-2725(14)00073-9. doi: 10.1016/j.biocel.2014.03.001. [Epub ahead of print]

Fungi in the cystic fibrosis lung: Bystanders or pathogens.

Chotirmall SH1, McElvaney NG2.

Author information

• 1Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Beaumont Road, Dublin 9, Ireland.
• 2Respiratory Research Division, Department of Medicine, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Beaumont Road, Dublin 9, Ireland. Electronic address: gmcelvaney@rcsi.ie.

Abstract

Improvement to the life expectancy of people with cystic fibrosis (PWCF) brings about novel challenges including the need for evaluation of the role of fungi in the cystic fibrosis (CF) lung. To determine if such organisms represent bystanders or pathogens affecting clinical outcomes we review the existing knowledge from a clinical, biochemical, inflammatory and immunological perspective. The prevalence and importance of fungi in the CF airway has likely been underestimated with the most frequently isolated filamentous fungi being Aspergillus fumigatus and Scedosporium apiospermum and the major yeast Candida albicans. Developing non-culture based microbiological methods for fungal detection has improved both our classification and understanding of their clinical consequences including localized, allergic and systemic infections. Cross-kingdom interaction between bacteria and fungi are discussed as is the role of biofilms further affecting clinical outcome. A combination of host and pathogen-derived factors determines if a particular fungus represents a commensal, colonizer or pathogen in the setting of CF. The underlying immune state, disease severity and treatment burden represent key host variables whilst fungal type, form, chronicity and virulence including the ability to evade immune recognition determines the pathogenic potential of a specific fungus at a particular point in time. Further research in this emerging field is warranted to fully elucidate the spectrum of disease conferred by the presence of fungi in the CF airway and the indications for therapeutic interventions. This article is part of a Directed Issue entitled: Cystic Fibrosis: From o-mics to cell biology, physiology, and therapeutic advances.