Cystic Fibrosis throughout history: how has life expectancy gone from being 14 years old to 40 years old?

calendarOctober 8 2020

Using Cystic Fibrosis as an example, Isobelle Moores discusses how developments in science other the years have impacted on the lives of many people with life changing conditions.

What is Cystic Fibrosis?

Cystic Fibrosis is a genetic disease that affects approximately 10,500 people in the UK. The disease is characterised by the body producing thick sticky mucus which can lead to a number of different health problems such as lung infections and digestive system issues. It is caused by there being a genetic defect (mutation) and there is no current cure. However, the disease is managed typically with several different approaches, such as airway clearance techniques and antibiotics, which can demand a lot of time each day.

Cystic Fibrosis treatment has come a long way throughout history, in the 1930s and 40s survival beyond childhood was rare. By 1969 the average survival age was 14 years old, which then doubled by 1990 to 28 years old. Now the life expectancy is between 35-40 years old for those in the UK and US, and death rates decreased annually by 2% during 2006 to 2015! So, what occurred for this to happen? In this blog we will explore how scientific advances and better understanding of the disease changed Cystic Fibrosis sufferer’s lives and how this provides hope for the future, not just for Cystic Fibrosis.

A Salty Brow

References to Cystic Fibrosis can be seen throughout history, such as this line from a Swiss 17th century song- ‘the child will soon die whose brow tastes salty when kissed’. Salty sweat is a classic symptom of Cystic Fibrosis but it was not identified until 1959.  In fact, Cystic Fibrosis was first described in 1938 by Dorothy Andersen. She was a pathologist in New York who, through autopsies of children, noticed a particular pattern of organ damage. Once the disease was named, treatment in the 1940s focused on tackling the symptoms with antibiotics such as penicillin, discovered in 1928. Changes to diet were also prescribed, including consuming a pancreatic extract to undo the damage Cystic Fibrosis does to the pancreas.

Up until the 50’s, diagnosis still involved relatively invasive testing and the presence of many symptoms. This was until the sweat test was introduced in 1959, and which is still used today. This test was born from just a simple observation in a New York hospital in 1948. During a heatwave, five infants with Cystic Fibrosis brought in with dehydration, had high salt (chloride) levels in their sweat. This was later confirmed for a larger population of Cystic Fibrosis sufferers and the test was created.

Simple Observations make all the difference

Meanwhile in England, physiotherapy was developing which involved breathing exercises and mechanical drainage. This requires placing the patient in different positions to allow mucus to drain out of the body.

By 1957, US paediatrician Leroy Matthews proposed a comprehensive treatment programme. It involved early diagnosis with the sweat test, regular physiotherapy and antibiotics chosen specifically for each patient. The method greatly reduced annual mortality in Cleveland, where Matthews was practicing, and showed the importance of multi-faceted symptom-focused care. This is still the bed rock of Cystic Fibrosis treatment now, and all of it stems from simple scientific observations.

Screening Newborns

In the 1970s diagnosis was further developed and allowed for neonatal screening whereby newborn babies are tested through the Guthrie Heel Prick test at a few days old. There were also advances in physiotherapy, antibiotic and pancreatic enzyme administration in the 70s and 80s, improving on existing treatments. 

A major breakthrough

However, in 1989 the gene that causes Cystic Fibrosis was discovered. More accurately, the gene that when faulty leads to the person having Cystic Fibrosis. The possibilities then seemed extremely exciting. It was suddenly possible to imagine the disease could be treated (through gene therapy), instead of treating the individual symptoms. This would be life changing for Cystic Fibrosis sufferers, who were already living longer but still spending many hours a day completing their medical regime.

The statistics show that since 1989 survival for Cystic Fibrosis sufferers has continued to improve. However, there are disagreements over the impact of the gene discovery. Although the discovery allowed for detection of carriers and highly accurate screening, there has been no major progression in the field of gene therapy. Improvements seen in life expectancy can be attributed to improved management of the symptoms and more people being able to access good care. This is despite huge amounts of research into gene therapy and drugs targeting the ‘root cause’, but this shows the difficulty in creating these types of treatments. It is also important to remember that almost 90% of clinical trials fail. This can be due to safety issues, the drug not being effective, or even lack of funding.

Still moving forward

However, after all these years there is still hope that lives can be further improved. Two new drugs were made available in 2012, that are small molecular drugs that target the root cause of Cystic Fibrosis. There was further good news in August 2020 that a new ground-breaking drug is to be made available on the NHS, once a European licence has been granted. This drug can treat 90% of Cystic Fibrosis sufferers!

This goes to show that progress is still very much occurring, but that these next steps may take a lot longer than the fast progression of the 1940’s to the 1980’s as the ‘low hanging fruit’ is gone and much more research is needed.

Cystic Fibrosis is an excellent example for showing how better scientific understanding leads to better treatment and then better lives. This scientific understanding can be anything from simple observations, like the observation of how Cystic Fibrosis targets the lungs and pancreas from the 1938 autopsies, to the discovery of the gene that causes Cystic Fibrosis. It is promising to see from Cystic Fibrosis that although it took 3 decades from gene discovery to producing a drug that targets this ‘root cause’, it still only took 3 decades for such a monumental achievement. This gives hope for further progression. Also, as these small molecular drugs are targeting the cause of the condition. They can hopefully cut down on the time spent by patients undergoing physiotherapy and other time-consuming treatments that target symptoms.

In addition, Cystic Fibrosis can also serve as a useful reminder that even when there is perhaps a lull in progress in developing new therapies for other conditions, there is still hope. Revolutionary drugs take time to be developed and as long as research continues, progress will eventually be made…

You can find out more about Cystic Fibrosis at the Cystic Fibrosis Trust.

About Isobelle

Biochemistry graduate from the University of Southampton. Isobelle has particular interests in treatments for genetic disease and nutrition.

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