Cystic fibrosis (CF) is a common genetic disease that is inherited from your biological parents and occurs because of abnormalities in our genes. The CF gene is the instructions on how to build a channel (or pore) in our cells that allows salt to move into and out of the cell. This salt channel is called CFTR, the cystic fibrosis transmembrane regulator. A mutation in this gene means that this salt channel does not work properly.
The lungs are the most commonly affected organ in patients with cystic fibrosis. As a result, patients with CF can have a chronic cough, phlegm production, shortness of breath, chest tightness, sinus problems and occasionally cough up blood.
A standard treatment regimen includes:
- airway clearance and exercise,
- chest physiotherapy,
- anti-inflammatory agents,
- supplemental oxygen, and
- nutritional support.
Nearly half of CF sufferers report poor sleep quality. Your oxygen levels may lower during an exacerbation and this is most noticeable during sleep. In some people these changes in breathing and oxygen during sleep can affect their performance during the day. They may have difficulties with concentration, memory and feeling tired during the day. People who have low oxygen levels while awake will usually also have low oxygen levels during sleep. In some cases, patients who may not require oxygen while awake may need extra oxygen while sleeping.
Individuals with CF can have low levels of oxygen in their bodies and some need to use supplemental oxygen to bring their oxygen levels up to a healthier level. Supplemental oxygen protects the body from the effects of low oxygen levels. It also helps your body to function better and allows you to stay more active. Some individuals only need oxygen when they are active or while sleeping, however, in most cases, oxygen should be used 24 hours a day.
A team led by UC San Francisco professor of medicine John Fahy, MD, has discovered why mucus in the lungs of people with cystic fibrosis (CF) is thick, sticky and difficult to cough up, leaving these patients more vulnerable to lung infection.
They found that inflammation causes new molecular bonds to form within mucus which transforms it from a liquid to a sludge.
This research has implications for other lung conditions characterized by thickened mucus, such as chronic obstructive pulmonary disorder (COPD) and asthma.
The scientists also made headway in the lab in exploring a potential new therapeutic approach to dissolve those bonds and return the mucus to a liquid that is easier for the lungs to clear.
Polymers – naturally-occurring molecules in mucus that form long chains – are the key to the discovery. Originally it was thought that there was just an increased concentration of these polymers with CF sufferers but now they know that more bonds form they just need to develop a drug that will break down and dissolve these extra bonds safely.
Fahy likened the polymers to logs floating down a river. “The logs can float down the river as long as they are floating independently,” he said. “But if you bolt them together side to side, they will clog the river.”
The researchers found that inflammation causes the extra disulphide bonds to form, when mucin polymers are exposed to highly reactive oxygen molecules released by inflammatory cells in a process called oxidative stress. Patients who are treated with pure oxygen have long been known to develop sticky mucus and this could be an unfavourable side-effect of the oxygen that’s used to treat them.
A new drug called TDG has been developed to target these mucin polymer bonds to re-liquefy a patient’s mucus but it is still going through the testing stages at present and will be at least 5 years away.
This new finding that explains the reason behind mucus thickening will not only help CF sufferers but other patients with lung diseases such as COPD and asthma. This potential new treatment in the pipeline could help millions of patients enjoy an easier more comfortable life if this drug can eliminate the problems of thickened mucus. It not only clogs up the lungs and makes breathing difficult and coughing it up distressing but also increases the risk of harmful infections taking hold, which could also be reduced with this new treatment.