Question

Why is there an increased risk for infections and other diseases with cystic fibrosis?

Answer 1

Cystic fibrosis patients have an increased risk of microbial infections. In normal healthy patients, the upper respiratory tract is colonized by normal flora of pathogens a while the lower respiratory tract is maintained in a sterile state by the various innate defenses of the host. Failure of any of these innate defenses results in susceptibility to pulmonary infection. One of the major infection associated with cystic fibrosis patient is microbes like  Pseudomonas aeruginosa .

The most prominent of the innate defenses of the airway is the mucociliary action of the airway epithelium. This clearance mechanism relies on the concerted action of two anatomic features: (i) the ciliated apical surface of the airway epithelium and (ii) a mucus layer that lines the airway lumen. When functioning normally, this clearance system traps foreign bodies in the mucus and subsequently carries them to the nasopharynx. while there is a mutation in CFTR gene results in increased mucus secretion from CF cells and it alters the viscosity of the airway. The abnormal mucus secretion results in the accumulation of foreign particles including microbes. The microbes further form a biofilm, which increases the chance of further infection.

This is the basic mechanism by which the microbial infection occurs in Cystic fibrosis patients.