Microscopic polyangiitis sparing the kidneys in a long-term survivor after allogenic bone marrow transplantation and...

Area of Science:

• Nephrology
• Rheumatology
• Immunology

Background:

• Allogenic bone marrow transplantation (BMT) can lead to various complications, including immune-mediated disorders.
• Microscopic polyangiitis (MPA) is a systemic vasculitis typically affecting small vessels, often involving the kidneys.

Observation:

• This report details an unusual case of MPA in a long-term survivor of allogenic BMT.
• The patient presented with cutaneous leukocytoclastic vasculitis and isolated pulmonary capillaritis, notably sparing the kidneys.

Findings:

• Serological analysis revealed a distinctive "double positive" finding: perinuclear antineutrophil cytoplasmic antibodies (p-ANCA) with anti-myeloperoxidase (MPO) activity and anti-glomerular basement membrane (anti-GBM) antibodies.
• Despite the atypical presentation, the vasculitis was effectively managed using prednisone and cyclophosphamide.

Implications:

• This case expands the understanding of MPA's potential clinical spectrum, particularly in the context of post-BMT complications.
• It underscores the importance of considering atypical presentations of vasculitis and the utility of combined serological markers for diagnosis.
• The successful treatment outcome suggests that established immunosuppressive regimens can be effective even in complex, rare presentations of MPA.