ANCA-associated vasculitis after hantavirus infection: A case report.

RATIONALE: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small and medium-vessel vasculitis that often leads to rapidly progressive glomerulonephritis. Although certain infections have been associated with ANCA formation, their role in triggering AAV is not fully understood.

PATIENT CONCERNS: A 60-year-old male who tested positive for hantavirus initially presented with fever, cough, and skin rash. Despite treatment with antibiotics for community-acquired pneumonia, his condition worsened, revealing elevated serum creatinine and proteinuria. Subsequent testing identified a significant increase in hantavirus antibody titers and positive anti-myeloperoxidase ANCA antibodies.

DIAGNOSIS: Laboratory tests and subsequent renal biopsy confirmed AAV with hantavirus infection.

INTERVENTION: Oral cyclophosphamide and high-dose glucocorticoids were initiated.

OUTCOMES: The patient's renal function deteriorated after immunosuppressive treatment, necessitating maintenance hemodialysis.

LESSONS: This is the first reported case of AAV following hantavirus infection, underscoring the need for vigilance in distinguishing AAV from other conditions in patients with viral infections.