Hemophagocytosis associated with MPO-ANCA positive vasculitis in systemic sclerosis

Hemophagocytosis is a histiocytic proliferative condition associated with underlying disorders such as infection, lymphoma and autoimmune disease. We describe here a patient with systemic sclerosis who developed MPO-ANCA positive necrotizing vasculitis and hemophagocytosis concomitantly. Vasculitis supervened on a prior systemic sclerosis, and no causative disorder of hemophagocytosis could be found other than active vasculitis, suggesting that an occurrence of hemophagocytosis is associated with underlying vasculitis. Immunosuppressive therapy resulted in excellent improvement of both the hemophagocytosis and vasculitis. On the other hand, this case shows the elevated serum levels of IL-1beta, IL-6 and M-CSF which may be involved in the pathogenesis of hemophagocytosis. To our knowledge, this is the first demonstration indicating the possibility of vasculitis-associated hemophagocytosis.