Fifty years ago, most babies born with cystic fibrosis (CF) died in childhood. Today, Canadian kids with CF can expect to live well into middle age.
This dramatic increase in survival is one of the great medical success stories of the last few decades. However, CF remains the most common fatal genetic disease in Canadian children, and kids with this incurable condition face a lifetime of time-consuming treatments, painful and debilitating symptoms, and the spectre of death in the prime of their lives.
Dr. Jonathan Rayment recently joined BC Children’s Hospital as an investigator, pediatrician and respirologist. Dr. Rayment is also a Clinical Assistant Professor in the UBC Department of Pediatrics. As both a researcher and a doctor caring for patients, Dr. Rayment is working to develop more sensitive and accurate tests of lung function in children. This could help doctors monitor children with CF and other lung conditions and provide them with treatment earlier, when it’s most effective.
Why is it important to improve tests that monitor lung function?
People with cystic fibrosis have a genetic mutation that causes secretions throughout the body to be unusually sticky and thick. These thick secretions negatively affect a number of organs and bodily systems including the pancreas, digestive system and sinuses, but have a particularly devastating impact on the lungs. In people with CF, this thick, sticky mucus causes the lungs to become infected and inflamed more easily. Over time, their lungs become more and more damaged, making it difficult for them to participate in everyday activities. Eventually, many people with CF need lung transplants, which can extend life but aren’t a cure, and most ultimately pass away due to lung disease.
Thanks to the incredible progress we’ve made in treating CF over the past fifty years, the traditional tests we use to measure lung function are usually normal in Canadian children with CF. However, we know that lung damage is occurring. If we do a CT scan for instance, we can see evidence of lung damage, but CT scans expose children to radiation, so we can’t use them on a regular basis.
Having a safer and more effective way to monitor lung function in children with CF would allow us to treat lung damage earlier, keeping kids healthier longer, and giving them the best chance to reach their full potential as adults.
This research also has implications for children with other serious health conditions. Some children who have bone marrow transplants to treat cancer or serious immune deficiencies develop lung damage as a complication. By the time we can see this damage on traditional test of lung function, it’s fairly advanced. It’s not too late to treat it, but it’s later than we would like. Early detection and sensitive monitoring are key to giving these children the most effective care.
What are you currently working on in your research?
I’m currently working on refining two types of tests that can measure lung function without exposing children to radiation, like x-rays and CT scans do. One is called multiple breath washout (MBW), and it’s existed in some form for decades. The lungs take in air, extract the oxygen that keeps us alive, and expel carbon dioxide, which the body can’t use. In people with lung damage, there may be pockets of the lungs that can do this efficiently, and other pockets of the lungs that don’t work as well. MBW can measure how effectively gases mix inside the lungs and how evenly this mixing is distributed throughout the lungs. MBW is a very sensitive test, so it has a lot of potential to help us detect lung damage earlier than traditional tests. We’re working to refine and improve its use for monitoring children with CF and other diseases that affect lung function.
I’m also working on developing the use of magnetic resonance imaging (MRI) technology to test for lung damage. Specifically, I’m studying a technique where we scan children while they breathe in tracer gas, a harmless gas that is visible on the MRI. We then look at the distribution of the gas in the lungs to see how effectively they’re working. Similar to the MBW test, the MRI can help us see if there are pockets of the lungs that aren’t working well.
Why did you decide to work with children with CF?
I decided to go into pediatrics after working in a CF clinic while I was in medical school – that’s how special the CF community is to me. Caring for a child with CF is a team effort. You have doctors with different specialities, nurses, social workers, pharmacists and physiotherapists all working together to support these children. I was drawn to being part of such a dynamic group of caregivers, and I think the multi-disciplinary support we provide for children with CF is really exemplary – it’s a paradigm of what the care of children with complex medical conditions can be.
The other thing that made me decide to work with children with CF is the amazing patient community. Families affected by this condition have really gotten behind advancing care and supporting research to develop new therapies. I think the success we’ve seen in improving the care for CF over the last few decades is due in large part to commitment of these families, working in concert with an amazing, multi-disciplinary clinical community.
How does your work with patients inform your research?
It’s hard to talk to a family in the clinic and have to tell them that I just don’t know or I just don’t have the answer to their question. These moments drive my research. I use research to answer the questions that I’m faced with every day when I treat patients.
It’s one of the advantages of working in a centre like BC Children’s Hospital that combines research and clinical care – I’m able to take dilemmas from the clinic and go tackle them in my research.
There’s a lot we still don’t know about the best way to provide care for children with CF, and it’s a great privilege to work in a place where I can use research to work towards a better future for my patients.
What is something people don’t realize about CF?
The therapies that have been developed for CF in the last few decades have made an enormous difference in survival rates, but they require a huge commitment from children and their families. A lot of these new treatments focus on reducing the sticky secretions the build up in the lungs and cause them to get infected and inflamed, leading to lung disease. A child might need to do five or six rounds of inhalation therapy, plus chest physiotherapy every single day. Cumulatively these therapies can take hours. These treatments work but they do require a significant sacrifice.
There is exciting research being done now to tackle the underlying problem that causes CF – a faulty protein involved in salt transport in cells. If we could fix this protein so it worked properly, the hope is that the other problems associated with CF might improve - or never start. These drugs are currently being tested in clinical trials, and have shown very promising results. With these emerging therapies, we hope to be able to save kids from facing a future of difficult therapies, debilitating symptoms and premature death. We do have a long way to go in caring for children with CF, but this is an exciting and hopeful time.