Detection and purification of antiidiotypic antibody against anti-DNA in intravenous immune globulin.

Pooled normal human IgG for therapeutic use, following depletion of anti-DNA, anti-Fc, and anti-F(ab')2 of normal IgG, expressed antiidiotypic activity against anti-DNA derived from lupus sera. The antiidiotype enriched by elution from anti-DNA affinity columns bound directly to anti-DNA IgG and inhibited the binding of lupus sera to DNA but did not bind to normal IgG or inhibit the binding of anti-tetanus toxoid to tetanus toxoid. Antiidiotypes in pooled normal sera may have a role in the clinical improvement seen in patients with autoimmune diseases receiving intravenous immune globulin.