Change in biomarkers of type-2 inflammation following severe exacerbations of asthma.

We investigated the time course of change of type-2 asthma biomarkers after a severe asthma exacerbation. Blood eosinophils were lowest immediately after treatment was initiated (0.07 vs 0.33x10(9)/L, p<0.001) while serum IgE levels were at their highest (339 vs 249 U/L, p<0.001). Fractional exhaled Nitric Oxide levels were lowest 2 weeks after treatment (23 vs 33 ppb, p=0.06) and serum periostin levels were lowest 1 week after treatment (45 center dot 9 vs 50 center dot 9 ng/mL, p<0.001). A delay of 4-8 weeks following a severe exacerbation is required if these biomarkers are used to guide the ongoing management of patients with asthma.