Characterization of the spontaneous autoimmune (anti-erythrocyte) response in NZB mice using a pathogenic monoclonal autoantibody and its anti-idiotype.

A monoclonal anti-mouse RBC antibody (G-8) has been prepared that appears to represent a pathogenic autoantibody related to those that arise spontaneously in aging NZB mice and which cause autoimmune haemolytic disease (AIHD). When G-8-producing hybridoma cells were grown as tumours in BALB/c mice, the mice developed AIHD characterized by a decrease in the number of erythrocytes (haematocrit) and the development of Coombs-positivity. An anti-idiotypic antibody (E8) was prepared against G-8 and was found to recognize an idiotypic determinant present on most autoantibody-forming cells derived from old (Coombs-positive) NZB mice. The results suggest that the IgM autoantibody response of NZB mice to self-erythrocytes is restricted to a limited number of clones, most of which express the G-8 idiotype.