New perspectives of biological therapy for severe asthma in adults and adolescents.

Severe asthma is associated with increased morbidity, mortality, healthcare costs and impaired quality of life. Asthma is no longer considered as a single entity but as a heterogeneous disease with different clinical presentations (phenotypes) and variable underlying mechanistic biological pathways (endotypes). Two different endotypes are based on the inflammatory Type 2 T-helper response: T2-high and T2-low.