Researcher Dr Robert Lethbridge with twins Sarah and Hannah Heyden, who are participating in the MAP study
The Kids Research Institute Australia researchers are investigating whether a simple urine test could predict whether young children with wheezing symptoms will go on to develop asthma.
Asthma is a chronic respiratory disease which begins in children as a wheeze – a whistling sound in the airways during breathing – but not all young children who wheeze go on to develop asthma. Around 70 per cent of pre-schoolers with recurrent wheeze grow out of it by the age of six.
However, because there are currently no clinically viable methods to determine whether children under the age of six have asthma – rather than just a transient wheeze caused by a viral infection or other problem – clinicians are left with little choice but to treat recurrent wheezers with asthma medication.
Dr Robert Lethbridge, a research fellow at The Kids and respiratory clinician at Perth Children’s Hospital, said this meant many children were being unnecessarily exposed to medications such as glucocorticosteroids, which could have significant long-term side effects including growth impairment.
“Almost 50 per cent of pre-schoolers will experience at least one episode of wheeze, with some of those children having symptoms severe enough to warrant medical attention,” Dr Lethbridge said.
“But because we have no way of knowing for sure which of those kids will stop wheezing and which will go on to develop asthma, that leads to us treating some patients that probably there’s no benefit in treating, and giving them medication that we know has side effects but no benefit.
“It puts children at risk and is not cost-effective. On the flipside, the lack of clarity means we end up not treating some children that might actually see an improvement if they started.”
He said although asthma was common – affecting around one in 10 Australians – it remained poorly understood.
“Asthma has had hundreds of millions of dollars poured into it over the decades and we have hints about the mechanisms behind it, however there’s still no one unifying understanding,” Dr Lethbridge said.
“There’s currently no way of firmly diagnosing it until at least two years of age, but really, the first time we are able to get any solid diagnostic test is around six years of age. That’s when kids can do a spirometry test – and even then some kids can’t do it because the test requires a lot of cooperation and breathing more than your body really wants. It can be hard for kids to understand the technique required.”
The Metabolomic Asthma Profile (MAP) study aims to find out whether a urine test could provide clarity much earlier in a child’s life, by revealing metabolic changes which can help predict the child’s likelihood of developing asthma.
Researchers including Dr Lethbridge hope to recruit 260 participants – both children with wheeze and children without wheeze – in two different age groups (2-4 years and 6-10 years).
The children will provide urine samples and will receive an assessment from a respiratory physician as well as lung function testing and allergy testing (skin prick test). Families will be asked to take part in two visits over a couple of months. If there is any exacerbation of the child’s wheezing during the period of the study, they may be asked to make a third visit.
Researchers will analyse the samples using metabolomics – highly sensitive metabolic profiling – to identify changes in the urine. They hope this will help them unlock the mechanisms behind asthma and enable them to tell the difference between asthma and other diseases which may be causing preschool wheeze.
“If we can get information from urine about what the body is doing that causes you to have asthma, then we can look more closely at it,” Dr Lethbridge said.
“The aim is to develop a clinically useful diagnostic test that differentiates transient wheeze from asthma.
“Being able to accurately diagnose asthma means kids will get more appropriate treatment. It’ll also help us understand a lot more about this condition.”
The study is a collaboration between The Kids Research Institute Australia, Perth Children’s Hospital, Murdoch University, and Edith Cowan University.
If you’d like more information or are interested in enrolling your child for this study, please visit the MAP Study page.