Inflammatory markers as exacerbation risk factors after asthma therapy switch from inhaled steroids to montelukast

BackgroundAsthma guidelines allow anti-leukotriene medications to be used as an alternative to inhaled corticosteroids (ICS) in second-step intensity therapy. The aim of the study was to analyze the risk factors of exacerbations, particularly inflammatory markers, during the 12-month period following therapy reduction from an ICS to montelukast in young patients with mild asthma.MethodsA total of 84 patients (aged 7–18 years old) with mild asthma controlled by low-dose ICS, had their treatment switched to montelukast. Exhaled nitric oxide (eNO), sputum eosinophils (sEos), and bronchial hyperreactivity (BHR) were assessed at the beginning and then every three months throughout the one-year period. The patients with asthma exacerbations (first severe or third mild) were discontinued from the study.ResultsOver the study period, 22 patients (26%) discontinued montelukast due to asthma exacerbations. An increased risk of exacerbations was noted among patients with initial sEos above 2.5% (relative risk, RR 36.6; 95% CI: 7.1–189.3; p < 0.001), as well as those with augmented BHR (RR 9.5; 2.8–31.6; p < 0.001), or eNO greater than 20 ppb (RR 3.7; 95% CI: 1.3–10.7; p = 0.013). An increase in BHR and eNO was observed during the last visit before exclusion.ConclusionsAfter switching treatment from a low-dose ICS, montelukast maintained control of asthma symptoms in 75% of patients. High sEos before the treatment change was the strongest exacerbation risk factor. In patients with asthma controlled by low-dose ICS and low inflammatory markers, treatment could be safely switched to montelukast.