This is particularly problematic for the lungs because the thick mucus impairs clearance of invasive particles and infectious agents to maintain a sterile environment.
Microbial contamination of airway surfaces triggers an inflammatory response, including a massive invasion by neutrophils (Rodrigues et al., 2008). As the neutrophils react to bacterial contamination of the lung tissue they generate considerable amounts of cellular debris that increases the viscosity of the mucous, primarily by the deposition of genomic DNA and elastase proteins. The result of this process is chronic microbial lung infection, chronic immune-mediated inflammation, and progressive tissue damage. Because cystic fibrosis lung disease is so severe the life expectancy used to be late teens or early adulthood, but the development of more effective methods for disease management has almost doubled life expectancy in recent years (Cystic Fibrosis Foundation, n.d.).
Haematology
There is increasing evidence that CFTR is expressed in polymorphonuclear leukocytes and may be required for proper phagosome acidification and bacterial killing (Conese et al., 2011). Impaired phagolysosomal function would explain why microbial lung infections are resistant to an immune response. In addition, platelets play an important role in haemostasis and may mediate some aspects of an inflammatory response. In individuals with cystic fibrosis, platelets display a number of defects and secrete proteins that signal the end of an inflammatory response. These findings have caused some researchers to debate whether stem cell therapy might be an effective treatment for cystic...
Currently, the most promising approach would be to use bone marrow mesenchymal cells to reconstitute 'wild type' function to the lung epithelium. The benefits would be reducing mucus viscosity and inflammation, and promoting tissue repair and an effective immune response.
References
Conese, Massimo, Ascenzioni, Fiorentina, Boyd, a. Christopher, Coutelle De Fino, Charles, de Smedt, Stefaan, Rejman, Joanna et al. (2011). Gene and cell therapy of cystic fibrosis: From bench to bedside. Journal of Cystic Fibrosis, 10, S114-S128.
Cystic Fibrosis Foundation. (n.d.). About Cystic Fibrosis: What you need to know. CFF.org. Retrieved 26 Feb. 2012 from http://www.cff.org/AboutCF/.
Li, Chunying and Naren, Anjaparavanda P. (2005). Macromolecular complexes of cystic fibrosis transmembrane regulatory and its interacting partners. Pharmacology & Therapeutics, 108, 208-223.
Rodrigues, Roberta, Gabetta, Carmen S., Pedro, Karla P., Valdetaro, Fabio, Fernandes, Maria I.M., Magalhaes, Patricia K.R. et al. (2008). Cystic fibrosis and neonatal screening. Cadernos Saude Publica, 24, s475-484.
