D1.140 - Beyond Severe Asthma: Eosinophilic Granulomatosis with Polyangiitis Unmasked by Acute Myopericarditis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic necrotizing vasculitis characterized by asthma, peripheral eosinophilia, and multiorgan involvement, with cardiac manifestations representing one of the leading causes of morbidity and mortality. This case report describes the clinical presentation, diagnostic work-up, and management of EGPA presenting as severe myopericarditis, aiming to highlight the importance of early recognition and treatment. In patients with severe type 2 eosinophilic asthma who remain poorly controlled despite step 5 therapy, with persistent eosinophilia and dependence on systemic corticosteroids, EGPA should be considered in the differential diagnosis.

The diagnosis of EGPA was established according to the 2022 American College of Rheumatology (ACR) classification criteria, integrating clinical features, laboratory findings, imaging studies, and clinical course, in order to support the diagnosis and exclude alternative clinical entities.

We report the case of a 30-year-old male, former smoker (10 pack-years), with a history of corticosteroid-dependent severe type 2 eosinophilic asthma and chronic rhinosinusitis. The patient exhibited poor clinical control despite optimized inhaled therapy and treatment with standard-dose mepolizumab, with minimal response. Therapy was subsequently switched to benralizumab, without clinical improvement and with persistent peripheral eosinophilia. Control spirometry showed a severe obstructive pattern.

After multiple emergency department visits for respiratory exacerbations initially attributed to SARS-CoV-2 infection, the patient developed pleuritic chest pain, worsening baseline dyspnea, and symptoms suggestive of heart failure, associated with marked eosinophilia (approximately 7,000 cells/µL) and elevated myocardial injury biomarkers. He was diagnosed with severe acute eosinophilic myopericarditis with biventricular dysfunction (left ventricular ejection fraction 21% and right ventricular ejection fraction 29%), which proved reversible following high-dose systemic corticosteroid therapy.

Hypereosinophilic syndrome was initially ruled out, and an extensive etiological work-up excluded infectious causes and other etiologies of myocarditis.

Given the suspicion of EGPA, with an ACR classification score ≥6 (maximum eosinophil count ≥1 × 10⁹/L, +5 points; obstructive airway disease, +3 points), treatment with mepolizumab at a dose of 300 mg every 28 days was initiated, resulting in good clinical response and a significant reduction in peripheral eosinophilia. During follow-up, the patient achieved good asthma control without the need for systemic corticosteroids; however, he developed progressive neurological symptoms, suggestive of peripheral mononeuritis.

This case highlights the importance of early identification of patients with severe eosinophilic asthma who present with persistent eosinophilia and poor clinical control despite optimal management of treatable traits and the use of standard-dose biologic therapies. In this context, EGPA should be actively considered, as delayed diagnosis may lead to severe and potentially life-threatening complications, such as the cardiac involvement observed in our patient. Early recognition and appropriate treatment are crucial to improve prognosis and prevent irreversible organ damage.