BAL surveillance has taught us a lot about early drivers of CF lung disease but there’s an urgent need to find less invasive biomarkers of pulmonary inflammation, the conference has heard.
Taking the audience through the results from AREST CF study Professor Peter Sly a paediatric respiratory physician from Brisbane in Australia said BAL surveillance had shown that neutrophil dominated inflammation and infection were important.
But BAL was not suitable as a true surveillance of disease because it was too invasive and could only be used infrequently, he told delegates.
There was a need to discover new and less invasive biomarkers but this would take time.
Biomarkers of inflammation, infection and structural damage could all be considered but if you think of early life then there’s a need to consider the matrix, he said.
For instance exhaled breath was possible but it wasn’t easy to do in infants. Sputum in early disease was not really an option, and children tend to not like blood tests.
“Our preferred matrix is urine and that’s where we’re putting in a lot of effort,” he told the audience.
“The ideal would be that when kids come to clinic they can bring a urine sample that we can dip stick and tell them how much their inflammation is playing up.”
However it was important to keep in mind that a biomarker that works in adults may not necessarily work in children.
A few years ago there was a lot of interest in measuring cyanide in sputum as a marker of Pseudomonas aeruginosa (P.a) infection, he explained.
When they looked at this in children using BAL they detected cyanide in two-thirds of the cohort despite only 16% being infected with P.a.
“So a biomarker that was thought to be promising in sputum from adults with chronic infection doesn’t work in children.. I guess that’s my cautionary tale.”
Sly and his team are using matched BAL blood and urine to try and validate potential biomarkers along with the clinical characterisation.
“I guess the message is watch this space and invite me back in a few years and I’ll tell you the answer,” he said.
In the mean time, he tells the audience to not be complacent.
“The fact that a child has no respiratory symptoms or signs of disease doesn’t mean they haven’t got infection or developing structural lung damage.”
“Be vigilant, if a kid is not growing as well as they should, if the parents tell you things are going on that you can’t see, be a bit careful and investigate those kids a little more aggressively than you would have in the past,” he concluded.