Real-life evidence of low-dose mepolizumab efficacy in EGPA: a case series.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, small vessel, necrotizing vasculitis. The disease is mainly characterized by hypereosinophilia and asthma with frequent sinonasal involvement, although multiple organs can be affected, including the heart, lungs, skin, gastrointestinal tract, kidneys, and nervous system. IL-5 production is pathogenetically central for the development of the disease by promoting proliferation, transvascular migration and functional activation of eosinophils.