FeNO helps identify responders to steroid therapy
MedWire News: Exhaled nitric oxide (FeNO) can identify patients with difficult-to-treat asthma and potential responders to high doses of inhaled corticosteroids or systemic steroids, research shows.
"This study adds to previous research showing a clinical utility of FeNO measurements in asthmatic patients," report Luis Pérez de Llano (Hospital Xeral-Calde, Lugo, Spain) and colleagues in the European Respiratory Journal.
The researchers add that FeNO measurements might help identify individuals with persistent eosinophilic inflammation in which a steroid response is more likely.
In patients with poorly controlled asthma, there is wide heterogeneity in the response to oral and inhaled corticosteroid treatment.
With this varied response, say researchers, some patients might be exposed to ineffective, and potentially harmful, therapy.
FeNO, an indirect marker of eosinophilic airway inflammation, has been proposed as a possible biomarker to assess disease, and has been shown capable of guiding asthma treatments.
In this study, the Spanish researchers evaluated the accuracy of FeNO for recognizing patients who have the potential to control their asthma with a guidelines-based stepwise strategy.
In total, 102 patients with suboptimal asthma control were treated with the maximal fluticasone-salmeterol combination dose for 1 month. Individuals who remained uncontrolled received oral corticosteroids for an additional month.
FeNO was "an excellent marker for predicting therapeutic response," according to researchers, with an area under the ROC curve of 0.925.
Baseline FeNO values >30 ppb had a sensitivity of 87.5% and a specificity of 90.6% for the identification of patients who will achieve control of their asthma. The negative predictive value was 90.6% and the positive predictive value was 87.5%.
In a multivariate analysis, FeNO was independently and significantly correlated with the achievement of asthma control.
The results, according to Pérez de Llano and colleagues, could help identify patients who are less responsive to steroid treatment and who might be at risk for developing persistent airway obstruction.
"These patients should be closely monitored and considered for novel anti-asthma drugs in order to prevent progression of the disease," they write.
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