Immunoglobulin and receptors for C3 on lymphocytes from patients with rheumatoid arthritis

Abstract

Abstract In peripheral blood of patients with rheumatoid arthritis the percentages of lymphocytes carrying surface‐bound IgG, IgA or IgM did not differ significantly from those in normal controls. However, both the sum of these percentages and the percentage of cells carrying receptors for human C3 were significantly lower than in normal controls. Immunoglobulin and C3 receptor were almost always present on the same cells, indicating that the latter also is a marker for B lymphocytes. In rheumatoid synovial fluids the percentage of lymphocytes carrying immunoglobulin appeared to be significantly higher than in peripheral blood from the same patients. No similar difference was observed for the percentage of cells carrying C3 receptors, probably due to impaired detection of this receptor in some of the fluids.