Noninfective endocarditis in microscopic polyangiitis: Report of a case with a successful response to...

Area of Science:

• Rheumatology
• Cardiology
• Immunology

Background:

• Antineutrophil cytoplasmic antibody (ANCA) vasculitis encompasses a group of systemic autoimmune diseases.
• While ANCA vasculitis can present with diverse clinical features, cardiac valvular compromise is an infrequent manifestation.
• Anti-myeloperoxidase (anti-MPO) antibody-associated vasculitis, a subtype of ANCA vasculitis, is particularly noted for its rarity of valvular involvement.

Observation:

• A 38-year-old woman with diagnosed ANCA-associated vasculitis presented with unusual valvular compromise.
• The patient exhibited findings consistent with valve vegetation, a serious cardiac condition.
• This presentation was specifically associated with anti-myeloperoxidase (anti-MPO) antibody positivity.

Findings:

• The valvular vegetation observed in the patient with anti-MPO ANCA vasculitis demonstrated a positive response to treatment.
• Successful resolution of the valve vegetation was achieved through immunosuppressive therapy.
• This suggests a potential pathogenic role for inflammation in the development of valvular lesions in this vasculitis subset.

Implications:

• This case expands the spectrum of clinical manifestations of ANCA-associated vasculitis, particularly anti-MPO vasculitis.
• It highlights the importance of considering cardiac valvular involvement in ANCA vasculitis patients, even when rare.
• The resolution of valvular vegetation with immunosuppression underscores the potential efficacy of targeted therapy for this uncommon complication.