[Fc-gamma-receptor cells and rheumatoid arthritis].

Certain blood lymphocytes of patients suffering from rhumatoid arthritis (RA) and or control subjects, can be detected using a rosette technique in the presence of erythrocyte antibody compounds (EA). The EA rosettes demonstrate the presence of cells having a receptor for the Fc fragment of the IgG's (Fc-receptor). A significant increase in highly active EA rosettes during RA was demonstrated using six EA compounds differing according to the type of erythrocyte and the quantity of sensitizing antibody. These highly active EA rosettes correspond to the case in which few antiserum molecules cover the erythrocytes. Their high level in RA may correspond to an increased number of Fc-receptor cells or to a stronger linkage of EA compounds. The cells forming EA rosettes are responsible for the resulting cell antibody cytotoxicity that seems to change little during rhumatoid disease. However, the very special behavior of Fc-receptor lymphocytes incubated in vitro suggests that the IgG receptors are modulated by the immune compounds present during RA.