Interleukin-5, Eosinophils, and Interleukin-5 Pathway Inhibitors in Eosinophilic Granulomatosis With Polyangiitis.

Interlukin-5 (IL-5) plays a crucial role in the pathogenesis of eosinophilic granulomatosis with polyangiitis (EGPA) by promoting eosinophil differentiation, activation, and survival. We present here a typical case of EGPA in which treatment with IL-5 pathway inhibitors is prescribed, showing to be beneficial for the patient. We discuss available evidence proving the association between IL-5 and clinical activity in EGPA and review the clinical efficacy and safety of currently approved IL-5 pathway inhibitors (i.e. mepolizumab and benralizumab) that improve disease control, reduce relapse rates, and have significant glucocorticoid-sparing effects in EGPA by reducing eosinophilic inflammation.