B-Cell-Depleting Therapy Improves Myocarditis in Seronegative Eosinophilic Granulomatosis with Polyangiitis

Area of Science:

• Rheumatology and Immunology
• Cardiology
• Internal Medicine

Background:

• Cardiac involvement in eosinophilic granulomatosis with polyangiitis (EGPA) significantly increases mortality.
• Current treatments like cyclophosphamide have cardiotoxicity concerns.
• B-cell-depleting therapy's efficacy in seronegative EGPA myocarditis requires further investigation.

Purpose of the Study:

• To evaluate the efficacy of B-cell-depleting therapy (rituximab) in patients with EGPA and cardiac involvement, particularly in seronegative cases.
• To assess the impact of rituximab on eosinophil counts, cardiac function, and clinical remission.

Main Methods:

• Retrospective study of 21 hospitalized active EGPA patients (aged 20-70) with high eosinophil counts and vasculitis scores.
• Ten patients had overt myocarditis.
• Rituximab (375 mg/m² weekly × 4) was administered for refractory or relapsed disease, with annual maintenance.

Main Results:

• All patients achieved lower eosinophil counts, improved cardiac dysfunction, and clinical remission.
• A median relapse-free follow-up of 48 months was observed post-induction.
• One patient relapsed with eosinophilia and cardiac insufficiency, responding to anti-IL-5 therapy.

Conclusions:

• B-cell-depleting therapy (rituximab) is effective in managing cardiac involvement in EGPA, including seronegative patients.
• Suppression of IL-5-mediated eosinophilia may be a key mechanism of action.
• Rituximab offers a potential alternative to cardiotoxic therapies for EGPA-related myocarditis.