Large-vessel arteritis and myelodysplastic syndrome: report of two cases.

Myelodysplastic syndrome (MDS) is frequently associated with autoimmune diseases such as polymyalgia, arthritis, and rarely, with systemic vasculitis. The pathogenesis of these autoimmune complications remains unknown, but there is increasing evidence of profound immune dysregulation in MDS. In the few cases reported so far, vasculitides associated with MDS affected mainly cutaneous vessels. Here we describe two cases of acute large-vessel vasculitis in association with MDS. The first patient is a 67-yr-old male presenting with a massive large-vessel arteritis as primary manifestation of refractory anemia with excess of blasts type 1 (RAEB-1). The second patient is a 60-yr-old male, who presented with acute thoracic aortitis after a 2-yr history of refractory anemia with ringed sideroblasts (RARS). Both patients received immunosuppressive treatment with steroids, leading to rapid improvement of systemic inflammatory symptoms, vessel wall injury and peripheral blood counts. Whereas the first patient displayed sustained favorable hematologic responses under long-term steroid therapy, there was a rapid transformation into secondary acute myeloid leukemia in the second patient. We conclude that large-vessel vasculitis should be added to the list of potential autoimmune complications in MDS. In this clinical setting, steroid therapy may alleviate inflammatory symptoms and result in beneficial hematologic responses.