MPO-ANCA-positive eosinophilic granulomatosis with polyangiitis complicated by alveolar hemorrhage treated with mepolizumab as an induction therapy: Case report

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis preceded by bronchial asthma or allergic sinusitis and accompanied by peripheral blood eosinophilia. Immunosuppressive drugs, such as cyclophosphamide in addition to high-dose glucocorticoids, are recommended for induction of remission in patients with severe EGPA. Although mepolizumab is widely recognized as remission induction therapy in non-fatal/non-organ disabling or relapsed/refractory EGPA, its efficacy and safety in induction of remission for severe cases have been ambiguous. In this context, we report a case of MPO-ANCA-positive severe EGPA in which the patient had a favorable course using mepolizumab as an induction remission therapy. The patient, a 74-year-old man, had MPO-ANCA-positive severe EGPA with alveolar hemorrhage. High-dose glucocorticoids and intravenous cyclophosphamide were started as remission induction therapy. However, after the initiation of intravenous cyclophosphamide, alveolar hemorrhage worsened, and there was development of opportunistic infections, such as aspergillus and cytomegalovirus antigenemia. Treatment with the antifungal drug voriconazole and the antiviral drug ganciclovir was started for opportunistic infection, and the treatment for EGPA was switched from intravenous cyclophosphamide to mepolizumab. As a result, alveolar hemorrhage improved, glucocorticoids were reduced, and the infection also improved. Mepolizumab as remission induction therapy for severe EGPA were thought to be appropriate and effective treatment in this case. However, the efficacy and safety of mepolizumab for this purpose require comprehensive evaluation.