Mepolizumab in pulmonary intensive care for eosinophilic granulomatosis with polyangiitis-associated life-threatening asthma: a case report

Abstract Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, characterized by asthma, eosinophilia and granulomatous or vasculitic involvement of several organs. Although biologic therapies targeting the interleukin-5 pathway are approved as maintenance treatment for EGPA, as well as for severe eosinophilic asthma, evidence supporting their use during acute critical illness is limited. We report the case of a 78-year-old Caucasian woman with ANCA-negative EGPA who developed a life-threatening asthma exacerbation leading to acute respiratory failure. Despite maximal conventional therapy, including systemic corticosteroids and intensive bronchodilation, respiratory failure was refractory. Subcutaneous mepolizumab was administered during the pulmonary intensive care unit (PICU) stay alongside systemic corticosteroids. Clinical and laboratory improvement was rapid, but is attributable primarily to systemic corticosteroid therapy; mepolizumab was reintroduced to re-establish long-term control of eosinophilic inflammation and to permit corticosteroid sparing. This case illustrates the diagnostic overlap between EGPA and severe eosinophilic asthma and the consequences of unsupervised discontinuation of anti-IL-5 maintenance therapy.