Hemophagocytic syndrome in a patient with rheumatoid arthritis

A 76-year-old man with rheumatoid arthritis, who had been treated with oral prednisolone and methotrexate, presented with high fever and generalized fatigability. Laboratory data demonstrated marked pancytopenia, which we first regarded as a side effect of methotrexate, and leucovorin was administered with granulocyte-colony stimulating factor and transfusions. Because no recovery was recognized, however, bone marrow aspiration was performed, by which hemophagocytic syndrome was diagnosed. After corticosteroid pulse therapy was initiated, the patient’s symptoms were rapidly attenuated and laboratory data rapidly normalized.