Long-term remission of neutropenia in Felty's syndrome after a short GM-CSF treatment.

We report a case of Felty's syndrome in which neutropenia was corrected by a short-term treatment with recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF, 5 micrograms/kg/day s.c. for 14 days). Absolute neutrophil counts rose from 0.1 to 2.2 x 10(9)/l and remained > 1.0 x 10(9)/l 8 weeks after discontinuation of the GM-CSF therapy. A flare-up of arthritis and a decrease in platelet counts were observed.