In Vitro Modulation of Anti-DNA Secreting Peripheral Blood Mononuclear Cells of Lupus Patients by Anti-Idiotypic Antibody of Pooled Human Intravenous Immune Globulin

Abstract

Anti-idiotypic antibody and its F(ab')₂ fragments prepared from pooled normal human IgG had a partial inhibitory effect on the spontaneous in vitro secretion of anti-DNA antibodies from blood mononuclear cells of lupus patients. The inhibitory effect was specific for anti-DNA secretion as the anti-idiotype failed to inhibit the spontaneous secretion of anti-tetanus toxoid in the same culture supernatants. Non-anti-DNA IgG or its F(ab')₂ fragments from pooled normal human IgG had less inhibitory effect on anti-DNA secretion than the purifieed anti-Id. In vitro polyclonal IgG secretion by lupus blood mononuclear cells was equally inhibited by both the anti-idiotype and the non-anti-DNA IgG of pooled normal human IgG. There was no correlation between the in vitro suppression of anti-DNA and that of total IgG or of anti-tetanus toxoid antibody. Pooled normal human IgG could have a potential beneficial effect in the therapy of systemic lupus erythematosus by inhibiting anti-DNA production via an anti-idiotypic mechanism.