Clinical trials involving very young children with cystic fibrosis may now be possible as researchers from Western Australia have developed a CT outcome measure that is sensitive to detecting the early progression of lung disease.
Chest CT is the gold standard for for demonstrating cystic fibrosis related structural lung disease but there are no validated quantitative outcomes based on CT that are appropriate for monitoring early lung disease in very young children, said the researchers led by Tim Rosenow from the Telethon Kids Institute in Perth.
“In an era that promises new disease modifying therapies an accurate and sensitive assessment tool is urgently needed both for monitoring disease progress and for clinical trials,” they wrote in the American Journal of Respiratory and Critical Care Medicine.
Using CT scans from the AREST CF cohort in Western Australia the researchers developed the Perth-Rotterdam Annotated Grid Morphometric Analysis Method (PRAGMA-CF) as a quantitative measure of airways disease.
They used a grid overlaid on ten axial slices to detect the presence of bronchiectasis mucous plugging or other airway abnormalities (inspiratory scans) and trapped air (expiratory scans). Thirty scans were used for observer reliability and thirty paired scans at 1 and 3 years old were used as a comparison.
Their findings confirmed that although the prevalence of SLD early in life is high, the extent is relatively low with a median proportion of lung volume affected being 0.87% and 1.86% at ages one and three respectively.
Quantitative PRAGMA-CF outcomes also showed high intra and interobserver agreement, were better correlated to neutrophillic inflammation than CF-CT scores and showed stronger relationships between structural changes and trapped air progression.
The data using PRAGMA-CF demonstrate that reliable quantitative estimates of lung disease can be obtained in young children, they said.
“We believe that the circumstances now exist to make CT a rationale choice as a primary outcome measure in clinical trials involving very young children with CF,” they concluded.