Felty's syndrome: an analytical review.

The clinical and laboratory features of 72 patients with Felty's syndrome described within the last ten years have been compared with Felty's five original patients. Felty's syndrome appears to be a variant of rheumatoid arthritis with extra-articular manifestations in which leukopenia (usually due to neutropenia) and splenomegaly occur, although not always at the same time. Both are manifestations of the underlying disease process and are not necessarily otherwise related. The mechanism of the leukopenia is complex and abnormalities in leukocyte function appear to be as important as the leukopenia in predisposing patients with Felty's syndrome to infection. Functional abnormalities of the leukocytes in this syndrome are due in part to immune complex formation. Hypocomplementemia associated with this process may be another cause for the increased susceptibility to infection. It is proposed, therefore, that therapy in Felty's syndrome be directed at the underlying disease process, and gold salts and penicillamine should be considered for this purpose. Splenectomy should be reserved for specific situations, such as hemolytic anemia, severe thrombocytopenia, leg ulcers, and infections associated with profound leukopenia that are not responsive to medical therapy.