Successful treatment by azacitidine therapy of intestinal Behçet's disease associated with myelodysplastic syndrome.

Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal hematopoietic stem cell diseases. It has been reported that several autoimmune diseases are associated with MDS. Recently, the co-occurrence of MDS with trisomy 8 and rare disorders of the immune system, such as Behçet's disease (BD), has been described. Prognosis in the older-onset group of MDS-associated BD is unfavorable. Here, we report a case of MDS-associated intestinal BD treated successfully by azacitidine therapy. A 59-year-old Japanese male suffering from recurrent high fever, melena, and oral and genital ulcerations was diagnosed with MDS with trisomy 8 and intestinal BD by endoscopic and bone marrow examinations. Immunosuppressive therapies, including infliximab, were ineffective. Due to his severe emphysema, the patient was considered ineligible for stem cell transplantation, and azacitidine therapy was initiated. With the exception of fever, the symptoms of intestinal BD improved, and severe malnutrition and anemia were ameliorated. Fluorescence in situ hybridization analyses of the bone marrow before the eighth cycle revealed that the trisomy 8 had not decreased. To our knowledge, this is the first report of azacitidine therapy for MDS-associated BD. We suggest that azacitidine may control intestinal BD by mechanisms other than those responsible for its effect in MDS.