An airway inflammation biomarker scale demonstrated potential to predict asthma attacks, new research found.
The novel ORACLE scale (Oxford Asthma Attack Risk Scale) demonstrated potential to predict — and subsequently prevent — asthma attacks using biomarkers of type 2 airway inflammation, according to new research.
Researchers sought to develop an effective risk scale to predict asthma attacks based on blood eosinophil count and exhaled nitric oxide. Trial-level data from 4 clinical trials — Novel START, CAPITAN, LIBERTY ASTHMA QUEST, and DREAM — were used to develop the scale.
Investigators analyzed and stratified attack rates for patients who received placebo (n=1989) by blood eosinophil and exhaled nitric oxide levels in a 3×3 grid with cut-off points of 0.15-0.30×109 cells/L and 25 to 50 ppb, respectively. From there, rate ratios and relative risks were used to derive biomarker-stratified multipliers for Global Initiative for Asthma (GINA) treatment step attack rates from 222,817 patients.
Biomarker-stratified asthma attack rates were then multiplied by 0.64 and 1.96 in the lowest and highest type 2 biomarker combination groups, respectively. History of a previous asthma attack and/or the presence of concurrent risk factors led to independently increased rates of 2.8-fold and/or 1.4-fold, respectively.
In the lowest biomarker step 1 and 2 patients, predicted annual attack rates were 0.06; in the highest biomarker step 5 patients, this risk was 2.4. Investigators noted a close agreement between observed and predicted asthma attack rates (intraclass correlation coefficient, 0.80; 95% CI, 0.56-0.90). “Our prototype scale based on biomarkers of type 2 airway inflammation proves feasibility and shows potential to predict asthma attacks which can be prevented by anti-inflammatory treatment, the researchers concluded.”