Link to Pubmed [PMID] – 1701301
J. Autoimmun. 1990 Oct;3(5):547-57
The present study demonstrates that normal human immunoglobulins for therapeutic use (IVIg) contain anti-idiotypes that recognize an antigen-binding site-related idiotope of anti-Factor VIII autoantibodies defined by a mouse monoclonal antibody (MoAb). MoAb 20F2 was obtained by immunizing a mouse with affinity-purified anti-Factor VIII F(ab’)2 fragments prepared from the IgG fraction of a patient with anti-Factor VIII autoantibodies. The monoclonal antibody was directed against an overlapping epitope on the antigen-binding site of the patient’s anti-Factor VIII autoantibodies and the CH1 domain of human IgG1. The anti-Factor VIII activity of the patients’s autoantibodies was neutralized by MoAb 20F2 in a dose-dependent manner. A fraction of the patient’s anti-Factor VIII auto-antibodies was specifically retained on affinity columns of Sepharose-bound MoAb 20F2; anti-Factor VIII activity of antibodies in this fraction was totally inhibited by MoAb 20F2, indicating an idiotopic homogeneity of retained anti-Factor VIII autoantibodies. IVIg inhibited the anti-Factor VIII activity of 20F2 idiotope-positive F(ab’)2 antibodies, thus indicating that the IVIg recognize the 20F2 idiotope on patient’s autoantibodies. These observations further support the concept of the presence in IVIg of anti-idiotypes against autoantibodies associated with human autoimmune diseases.