Antiglobulin production to altered IgG in rheumatoid arthritis.

Conformationally altered IgG molecules have been detected in the serum of patients with rheumatoid arthritis. A hypothesis is presented that specific T-cell unresponsiveness to autologous IgG can be bypassed through the recognition of the altered IgG by competent B lymphocytes. The recognition of altered IgG is mediated through membrane Fc receptors (which may themselves be different in rheumatoid arthritis) and this favours stimulation of those cells carrying a specific receptor for an antigenic part of the molecule. A particular cellular arrangement may be required for complete antigenic stimulation and antiglobulin production. The resultant antiglobulin can have the same binding affinity for autologous and homologous IgG since the antigenic part of the molecule need not be a structurally altered site.