Eosinophilic Asthma

Abstract

Eosinophilic asthma is known as a main phenotype of asthma classified on the basis of immune cells involved in inflammatory response in the respiratory airway. Eosinophilic asthma can be related to increased severity of asthma, allergic sensitization, adult onset, and increased resistance to corticosteroids. The prevalence of eosinophilic asthma is 32–40% among asthmatic patients. Different cells and cytokines are involved in its pathogenesis including eosinophil, mast cells, type 2 helper T cells, innate lymphoid cells, IL-4, IL-5, and IL-13. Eosinophil count in induced sputum and bronchoalveolar lavage is the yardstick for recognizing and distinguishing eosinophilic asthma from non-eosinophilic asthma, while various tests which are noninvasive such as fractional exhaled nitric oxide and periostin are arising as possible substitutes. Novel and advanced therapies new and advanced therapies and more convenient biological drugs, Leads to high requirement for particular endotype- and phenotype-related treatment plans. Identification and knowledge of the specific pathophysiology of eosinophilic asthma have great association with disease management and chances for better patient prognosis. Further, Th2 cells also secrete IL-5, which activates and recruits eosinophil. IgE-dependent degranulation of mast cells secretes both immediate and newly formed mediators like leukotriene, prostaglandin cytokines, etc. other important cells contributing to asthma pathobiology are type 2 innate lymphoid cell (ILCs2), producing IL-13 and IL-5 which cause eosinophil recruitment and expansion in nonallergic eosinophilic asthma.