[Hemophagocytic syndrome in a patient with rheumatoid arthritis].

A 62-year-old man with 16 year-history of rheumatoid arthritis (RA) was admitted due to progressive pancytopenia, general fatigue, and high fever. He was treated with 5 mg methotrexate weekly in RA. His bone marrow examination revealed a decreased nuclear cell count (2.1 x 10(4)/microliter), megakaryocyte count (16/microliter), and macrophages phagocytizing blood cells (13.2%), indicating the presence of hemophagocytic syndrome. No infections agent was detected in cultures derived from his blood or other sources. The serological tests for several viruses revealed no obvious viral etiology. The systemic lymphonodes were not swelling. Administration of 40 mg prednisolone daily improved his abnormal hematological findings. This is a case of RA accompanied by hemophagocytic syndrome, which is a rare complication of RA.