A 65-year-old woman who has a 12-year history of symmetrical polyahritis is admitted to the hospital. Physical examination reveals splenomegaly, ulcerations over the lateral malleoli, and synovitis of the wrists, shoulders, and knees. There is no hepatomegaly. Laboratory values demonstrate a white blood cell count of 2500/uL and a rheumatoid factor titer of 1:4096. This patient's white blood cell differential count is likely to reveal

(Braunwald, 15/e, pp 369,1932.)Felty syndrome consists of a triad of rheumatoid ahritis, splenomegaly, and leukopenia. In contrast to the lymphopenia observed in patients who have systemic lupus rythematosus, the leukopenia of Felty syndrome is related to a reduction in the number of circulating polymorphonuclear leukocytes. The mechanism of the granulocytopenia is poorly understood. Felty syndrome tends to occur in people who have had active rheumatoid ahritis for a prolonged period. These patients commonly have other systemic features of rheumatoid disease such as nodules, skin ulcerations, the sicca complex, peripheral sensory and motor neuropathy, and aeritic lesions.