Asthma is a heterogeneous disease with regard to the inflammatory pathways activated.
In recent years, biologic drugs (monoclonal antibodies) directed towards specific components
of type 2 inflammation have been approved for the treatment of severe asthma. Phenotyping
of patients with severe asthma and evaluation of biomarkers have been recommended
to help identify patients who are candidates for treatment with biologics and to monitor
Fractional exhaled Nitric Oxide (FeNO) is a biomarker of type 2 inflammation in asthma, signaling
activation of Interleukin (IL)-4/IL-13 pathway. FeNO could be useful to assess treatment
response or identify candidates for a specific drug that acts on type 2 inflammation
mechanisms linked to Nitric Oxide (NO) production, such as the IL-4/IL-13 pathway or upstream
The value of FeNO as a biomarker predictive of responses to the biologics available for treating
severe asthma is discussed based on the published studies at the moment of the review.