AN UNUSUAL ASSOCIATION OF FELTY SYNDROME AND TCR-GAMMA-DELTA LYMPHOCYTOSIS

Felty syndrome, comprised of neutropenia, rheumatoid arthritis and spl enomegaly, occurs in approximately 1% of patients with rheumatoid arth ritis. Up to one third of these patients have an increased number of l arge granular lymphocytes. The usual immunophenotype of these cells is CD3+, CD8+, CD57+, T cell receptor (TCR) alpha beta. A patient with F elty syndrome and large granular lymphocytosis, who had an unusual imm unophenotype CD3+, CD4-, CD8-, TCR gamma delta, is described. Her neut ropenia responded to treatment with granulocyte colony stimulating fac tor (G-CSF), which was given in order to raise her neutrophil count pr ior to bilateral knee replacement surgery. Thus, Felty syndrome with l arge granular lymphocytosis is a het condition, one in which TCR gamma delta large granular lymphocytosis may be found, and also shows a res ponse to treatment with G-CSF.