Treatment of Felty's syndrome with the haemopoietic growth factor granulocyte colony-stimulating factor (G-CSF)

Felty's syndrome (FS) (rheumatoid arthritis with neutropenia andsplenomegaly) has a poor prognosis, largely because of the high risk ofsevere infection. Granulocyte colony-stimulating factor (G-CSF) is anemerging treatment for chronic neutropenia. We prospectively monitored itsuse in eight patients with recurrent infections or who required jointsurgery. Significant side-effects were documented in five, includingnausea, malaise, generalized joint pains, and in one patient, a vasculiticskin rash. In two patients treatment had to be stopped, and in these casesG-CSF had been started at full vial dosage (300 micrograms/ml filgrastim or263 micrograms/ml lenograstim) alternate days or daily. G-CSF treatment wascontinued in three patients by restarting at reduced dose, and changing theproprietary formulation. G- CSF raised the neutrophil count, reduced severeinfection, and allowed surgery to be performed. A combined clinical andlaboratory index suggested that long-term treatment (up to 3.5 years) didnot exacerbate the arthritis. Once on established treatment, it may bepossible to use smaller weekly doses of G-CSF to maintain the same clinicalbenefit. One of the three patients whose FS was associated with a largegranular T-cell lymphocytosis showed a reduction in this subset oflymphocytes during G-CSF treatment.