Eosinophilic vasculitis of aortic valve in EGPA: a life-threatening onset of disease

Introduction: Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss Syndrome, is an anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis that can manifest with a wide spectrum of clinical presentations. Indeed, EGPA is characterized by eosinophil-rich inflammation and systemic necrotizing vasculitis affecting small-to-medium-size vessels of different organs. Cardiac involvement is associated with a poor prognosis, and it is mainly described in the form of myocardial eosinophilic infiltration. Aortic valve involvement of EGPA is exceedingly rare. Case study: A 51-years-old man with eosinophilic severe asthma and chronic rhinosinusitis with nasal polyps presented to the Emergency Department with worsening dyspnea after a two months history of low-grade fever and malaise; home therapy included anti-IL-5 monoclonal antibody (100 mg every four weeks). At the Emergency Department, the patient developed cardiac arrest and, after advanced life support maneuvers, he underwent surgery for acute torrential aortic regurgitation. Results: Pathological examination of native aortic valve showed widespread vasculitis with eosinophilic inflammatory infiltrate and ANCA antibodies (anti-MPO), previously negative, tested positive. A diagnosis of EGPA was therefore made, despite low blood eosinophils probably due to mepolizumab therapy. Mycophenolate mofetil and high dose mepolizumab (300 mg every 4 weeks) were started and the patient was discharged with full resolution of his clinical picture even at the three months follow-up visit. Conclusion: To our knowledge, this is the first reported case demonstrating angioplasia and vasculitis on the aortic valve. Our case report shows the importance of appropriate mepolizumab dose to improve EGPA clinical outcomes; moreover, severe disease activity despite low dose mepolizumab could underline the role of alternative pathogenic mechanisms beyond IL-5 pathway, at least in some patients.