A researcher from the Faculty of Medicine, Shiraz University of Medical Sciences, in Iran, has suggested the unconventional idea that people with cystic fibrosis (CF) could be more resilient to cholera and, vice versa, that people who contract cholera could develop resistance to cystic fibrosis. The work, titled “Cystic fibrotics could survive cholera, choleraics could survive cystic fibrosis”; hypothesis that explores new horizons in treatment of cystic fibrosis,” appeared Oct. 26, 2015, in the journal Medical Hypotheses.
This journal presents ideas from investigators before they have conducted actual research to confirm them.
The idea behind Dr. Arsalan Azimi’s paper is that cholera may cause loosening of the thick mucus that builds up in people with CF.
Cystic fibrosis is one of the most commonly occurring chronic lung diseases in children and young adults, and can be a life-threatening disorder. Breathing is often difficult for people with cystic fibrosis due to a sticky mucus that builds up in the lungs and all too often leads to serious, even fatal, bacterial infections.
Mutations in the CFTR gene are the major cause of this mucus buildup in cystic fibrosis. Scientists have identified over 2,000 mutations in the CFTR gene that are associated with the disease, which normally presents in patients at birth. CFTR, which stands for Cystic Fibrosis Transmembrane Conductance Regulator, helps shuttle chloride ions in and out of cells, balancing salt and water in the cells that line the lungs. When CFTR is mutated, there is a dysfunction in this process and an overproduction of thick mucus.
Cholera is an infection caused by contaminated food or water that contains the bacterium Vibrio cholerae. It symptoms appear rapidly, between two hours and five days.
In his somewhat controversial paper, Dr. Azimi “hypothesized that cholera toxin (CT) could ameliorate symptoms of cystic fibrosis as CT could dilute the thickened mucus, improve mucociliary clearance and alleviate airway obstruction. CT strengthens immunity of airway mucosa and it could [attenuate] bacterial growth and reduce persistency of infection. CT also modulates cellular immune response and it could decrease airway inflammation, hinder airway remodeling and prevent respiratory deterioration.”
Naturally, this idea requires extensive testing before it could potentially be realized in humans. In addition, for cholera toxin to be an effective treatment for CF, its dangerous properties would need to be experimentally reduced. However the idea is not completely unprecedented, since the botulinum toxin, for example, is used in low doses for medical and cosmetic purposes.