Glycoprotein specificity of cold-reactive IgM antilymphocyte autoantibodies in systemic lupus erythematosus.

Sera from patients with systemic lupus erythematosus frequently contain IgM antibodies to glycoproteins of Mr 46,000 and approximately 200,000 isolated from nonionic detergent lysates of mature T cells by affinity chromatography with solid-phase wheat germ agglutinin. Autoantibodies of this specificity correlate strongly with the presence of IgM anti-T cell autoantibodies, as determined by independent indirect immunofluorescence and complement-dependent microcytotoxicity assays, and are specifically absorbed by incubation of patient serum with viable T cells. Collectively, the data suggest that gp46 and, to a lesser extent, gp approximately 200 represent major targets of IgM antilymphocyte autoantibodies in systemic lupus erythematosus.