Rheumatoid arthritis associated with expanded populations of granular lymphocytes

Abstract

Two patients with classic rheumatoid arthritis developed severe neutropenia and increased numbers of large granular lymphocytes in the blood and bone marrow. These lymphocytes exhibited homogeneous surface membrane immunophenotypes of Leu5+, Leu11-, Leu4+, Leu3-, Leu2-, Leu7+ and Leu5+, Leu11+, Leu4+, Leu3-, Leu2+, Leu7-, respectively. In both patients, neutropenia was initially corrected with corticosteroid therapy; long-term improvement followed low-dose oral cyclophosphamide and methotrexate therapies. In these 2 patients and 12 previous patients with rheumatoid arthritis associated with expanded populations of immunophenotypically homogeneous large granular lymphocytes, neutropenia occurred in all 14, thrombocytopenia in 6, anemia in 7, and mild or moderate splenomegaly in 12. In contrast to Felty's syndrome, granular lymphocyte expansions in rheumatoid arthritis usually occur in older patients, may appear simultaneously with arthritis, and are usually associated with normal or elevated blood leukocyte counts. Mild hemocytopenias in these patients can often be managed with observation. Therapy with corticosteroids or immunosuppressive-cytotoxic drugs may be beneficial in more severe cases, but splenectomy is not recommended.