Chronic cough in children causes considerable health problems and health care costs. Protracted bacterial bronchitis (PBB), is a common cause of chronic cough in children and was first described by our team in 2006. Even though many children with PBB get better with 2 weeks of antibiotics, we found a group of children in whom PBB recurs. In our preliminary studies, we found that those children with recurrent PBB are more likely to be diagnosed with the debilitating chronic respiratory illness, bronchiectasis, within 2 years.

We have funding from the National Health and Medical Research Council (NHMRC) to investigate the long term clinical outcomes of children with recurrent PBB . We will also investigate possible predictors of recurrent PBB which may help to identify children who are likely to get recurrent PBB disease and therefore are more likely to progress to bronchiectasis.

The CRE funding will allow us to undertake digital gene profiling of blood cells from children with and without PBB and inflammation of the lungs. This may help us further understand the mechanisms of recurrent PBB and to identify biomarkers which may predict PBB recurrence. Our aim is to increase the understanding of PBB and ultimately to improve clinical management of children who suffer from this common condition.

Main findings from the study;

• Interleukin (IL)-1β regulates the immune response to common respiratory pathogens in children with PBB.
• The IL-1β-dominated inflammation in PBB is likely driven by multiple inflammasomes (NLRP3 and AIM2).

These findings have been published in

ERJ Open Res. 2017 Oct 2;3(4):00025-2017 doi: 10.1183/23120541.00025-2017

ERJ Open Res 2018 Mar 3;4(1):00130-2017. doi: 10.1183/23120541.00130-2017