[A case of antigranulocyte antibody positive Felty's syndrome and its efficacy of plasmapheresis].

The patient is a 44-year-old female case of RA having a history of 10 years after onset, being admitted due to fever accompanied by granulocytopenia. By laboratory findings, WBC was 1,900/mm3, CRP 5+, RA 2+, RAHA 80 times, LE cells positive, antinuclear antibody strongly positive, granulocyte-specific antinuclear antibodies positive, and granulocyte specific cytotoxicity test strongly positive. Examination of bone marrow smears revealed, the cell numbers tended to decrease in the neutrophil maturity phase. The case was diagnosed as Felty's syndrome because of the obvious splenomegaly and leukopenia. Administration of 30 mg/day of prednisolone was not sufficient in effect, and plasmapheresis was conducted concomitantly. As a result, the granulocyte count increased and the granulocyte cytotoxicity titer was lowered. It is hence suggested that the antigranulocyte antibodies are responsible for the mechanism of granulocytopenia in this case, and the possibility of promotion of destruction in the periphery was inferred, and it is accordingly considered useful to combine administration of small dose of adrenocortical steroid preparation with plasmapheresis for the treatment of this disease.