Eosinophilic Granulomatosis with Polyangiitis (EGPA, Churg–Strauss)

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly called Churg–Strauss syndrome, is a systemic necrotizing vasculitis of small- and medium-sized vessels, characterized by asthma and blood eosinophilia. It usually occurs in individuals with preexisting asthma, and involves the skin, lungs, and peripheral nerves. Anti-myeloperoxidase antineutrophil cytoplasm antibodies are detected in a third of the patients; positivity or negativity of those autoantibodies seems to distinguish two phenotypes, with different clinical characteristics and prognoses. The Five-Factor Score (FFS) is an assessment of poor-prognosis factors, i.e., gastrointestinal tract, heart kidney, and/or central nervous system involvement(s). Although glucocorticoids and immunosuppressants have dramatically improved overall survival, relapse rates remain persistently high. Glucocorticoids should be prescribed to all patients, with adjunction of immunosuppressants (cyclophosphamide for induction and azathioprine or more recently developed agents for maintenance therapy) for those with severe/refractory disease and FFS-defined poor prognoses. And, now, novel advances in EGPA management include immunomodulatory and targeted therapies being evaluated to improve EGPA patients’ prognoses: e.g., rituximab and anti-interleukin-5 agents for remission induction, and mepolizumab has been proven effective as maintenance therapy against relapses.