Study of the effects of antigammaglobulin factors on lymphocytes from patients with rheumatoid arthritis.

Previous work suggests that peripheral blood lymphocytes from patients with rheumatoid arthritis have altered reactivity. The purpose of this study has been to observe the behavior of cultures of lymphocytes from patients with rheumatoid arthritis when stimulated with autologous 19S rheumatoid factor and with rabbit serum against autologous IgG fraction. The peripheral blood lymphocytes (PBL) from 15 patients with classical rheumatoid arthritis were obtained by passage of the leukocyte-rich plasma through a polyamide fiber column. The purified lymphocytes were cultured with rheumatoid factor obtained from the same donor through Sephadex G-200 chromatography. In another set of experiments rheumatoid lymphocytes were stimulated with rabbit serum containing antibodies against the IgG fraction of the same patient obtained through DEAE chromatography. After five days the lymphocytes were examined for large cells plus cells in mitosis. A positive response was defined as an increase of 5% or more in the experimental tubes when compared with the cells cultured alone. Ten healthy normal subjects were used also as lymphocyte and serum donors. These lymphocytes were cultured alone and with rabbit serum, anti-autologous IgG. 80% of rheumatoid lymphocytes responded with an average of 37% of enlarging and dividing cells when stimulated by autologous RF. The same pannel of lymphocytes responded only with an average of 14% stimulation when cultured with rabbit serum anti-autologous IgG. The response to the 7S antigammaglobulin factor from rabbit in 7 normal PBL was similar to that of rheumatoid lymphocytes. There was some relation between activity of the RA and lymphocyte response to RF and rabbit antiserum. These results could explain the lymphoid infiltration and hyperplasia of patients with RA and, on the other hand, would support the idea that entrapment of RF by leukocytes ('RA cell') would be a protective mechanism.