Cystic Fibrosis: Bugs, Drugs and Lung Transplantation

Written by Rosadelle Tirados, edited by Lucy Eland

For our final SciBar of the year, Advanced Biomedical Scientist Audrey Perry, from the Freeman Hospital in Newcastle, shared with us some fascinating insights into cystic fibrosis (CF) and its current therapies. This genetic condition brings about a build-up of sticky mucus in the lungs and pancreas and difficulty in breathing which, along with frequent lung infections, can be very challenging for a CF patient. With over 10,000 people affected in the UK, is there hope for a more effective management of this condition?

It has been found that mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene can wreak havoc on the normal transport of epithelial fluid in our lungs, pancreas and other organs. There are six classes of mutations affecting the CFTR gene and it is important to recognise which one a patient has in order to select the most suitable therapy. CF manifests in many different ways across the whole body including heart disease, hypertension, bronchitis and pneumonia. Unlike in normal lungs, mucus in the CF lung is very thick, persistent and difficult to remove. Detecting the faulty gene early is therefore critical, so treatments can be started as soon as possible. Since 2007, all new-borns in the UK have been screened, using a genetic ‘heel prick’ test.

Treatments for CF include inhaled drugs that help to clear the airways, antibiotics for lung infections, physiotherapy and nutritional feeding among others. Kalydeco (Ivacaftor) is the first precision medicine for CF that is available in the NHS. It is a ‘personalised’ medicine, specifically targeted to CF patients with a gating mutation such as G551D and allows for the normal balance of salt and water in the cells in the lungs. Orkambi (Ivacaftor/Lumacaftor) is another precision combination therapy that is used to help get more proteins in the surface of cells and to maintain the normal flow of salt and water in the lungs – although at the moment it is not available in the NHS. With ongoing research into other drugs and therapies, who knows what new drugs will be introduced in the near future. Watch this space!

For those who are unable to get any benefits from these drugs, a double lung transplant is another option. It is not to be taken lightly, however, as specific criteria (such as very poor lung function and high burden of care) must be met by those considering undergoing this procedure. Tests must also be performed to ensure you do not have Burkholderia cenocepacia or Mycobacterium abscessus complex in your lungs. Having these bugs in your lungs before the transplant may contribute to the failure of the transplant and death due to infection. These bugs can remain in the throat or chest cavity and infect the new transplanted lung, which is a huge problem when the patient’s immune system is already compromised by the transplant. Freeman Hospital survival rates are 84% at 1 year post transplant, 70% at 3 years, 60% at 5 years and 53% at 10 years, which is relatively high, but obviously worth improvement!

Is it just the advances in lab testing and therapies that contribute to the safe management of this condition? Of course not! We have specialist CF teams to thank for their hard work, in addition to the expert microbiologists who tailor specific treatments to the patient, to the biomedical scientists who test patient samples, nurses, social workers and other healthcare professionals that deliver care at the bedside. It truly is a team effort and just as important is the commitment and compliance of the patient to their therapy.

CF is a life-limiting inherited disease and there is currently no cure, however, with advances in testing and personalised medicine, there are high hopes for a better life expectancy and ultimately a world without CF.

For more information on CF and lung transplantation, please visit:

https://www.cysticfibrosis.org.uk/

https://www.ishlt.org/publications-resources/standards-guidelines/guidelines,-consensus-documents,-and-standards-sta

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s