ABSTRACT
A 63 year-old female patient with rheumatoid arthritis and positive rheumatoid serology presented persistent neutropenia without spleen enlargement detectable by either physical or isotopic means. A pattern identical to that described for classical Felty's syndrome was found on determination of the IgG bound to granulocytes by inhibition of the hemolysis of sheep erythrocytes previously incubated with human IgG. Inhibition of hemolysis in the patient was 94 %, 63 %, and 32 % (according to the concentration of granulocytes per mm3), while in the healthy control it was 37.5 %, 30 %, and 0 %, respectively. In spite of the absence of spleen enlargement, the patient was diagnosed as suffering from Felty's syndrome without splenomegaly. The diagnostic and follow-up value of the measurement of IgG bound to granulocytes is emphasized.