How to diagnose children with asthma when there is no standard test? That’s the question Dr Robert Lethbridge from Telethon Kids Institute is seeking to answer in his Metabolomic Asthma Profile study (MAP) currently underway.
It has had the clinician/researcher focusing on urine as the possible marker.
“We can work out differences in chemical composition of the urine from kids that we see with asthma verses kids that don’t have asthma or who never wheezed,” he said.
Currently, there is no clinically viable methods to identify if a child under six has asthma, or is wheezing. Earlier studies have found differences between asthma and non-asthma but looked at adults and older children, so MAP is the first time young children (2-4 years old and 6-10 years) have been studied.
“It’s probably the youngest cohort on which this testing has been done. Their age is salient due to the difficulty in differentiating asthma from wheezing, especially given the specific tests necessary for diagnosis.”
The accuracy of asthma diagnosis in children is problematic, Robert says.
“Children just can’t do spirometry and lung function testing even at six or so, let alone younger.”
“It’s a lot of educated guessing when it comes to deciding on what child will benefit from medication, and with asthma it’s mostly inhaled steroids. That means there is probably a group of kids who are on therapy without any real benefit and being unnecessarily exposed to medication with potential side effects.”
“There might also be children experiencing wheezing who are not on medication and might genuinely benefit from it.”
The potential of a diagnostic urine test for asthma diagnosis is significant. Currently, doctors rely on self-report data from patients’ parents and medical history.
“There’s not much more GPs can do and they do it amazingly, that is, take a good history, investigate family history and put all of these presentations and clinical findings together to come up with a picture about how this child’s respiratory health is. There is nothing fancier that you can really do,” Robert said.
If this study can identify asthma in urine, it will lead to a paradigm shift in how GPs diagnose the condition.
“Often by the time patients have hit a GP or hospital, they are actually better, or at least they are not in that flare-up, which makes things more difficult to diagnose. Hopefully a more objective test will be useful for making those calls.”