Demonstration of rheumatoid factor idiotypic antigens on peripheral blood B and T lymphocytes from patients with rheumatoid arthritis.

Antisera were raised against three polyclonal IgM rheumatoid factors (RF). After adequate absorptions, the antisera were rendered idiotype-specific, as assayed by haemagglutination technique. By using the anti-idiotype antisera in indirect immunofluorescence on peripheral blood lymphocytes from the patients used as donors for the immunizing RF, it was demonstrated that 3-14% of the lymphocytes were stained, and thus had membrane-bound structures with idiotypic antigens similar to those of the circulating IgM RF of the same patients. While most of these idiotype-positive lymphocyte were B lymphocytes, it was demonstrated in one patient that about 7% of the T lymphocytes also had the same idiotypic antigens.