Pathophysiology of antinuclear antibodies in systemic lupus erythematosus and related diseases.

Antinuclear antibodies in systemic lupus erythematosus (SLE) and related diseases have been used for characterizing nuclear antigens and for elucidating immune mechanisms that drive the autoimmune response. Each disease has its own characteristic profile of antinuclear antibodies, which has been useful for diagnostic purposes. In the biological context, concepts emerging from studies on nuclear antigens and antibodies show that the autoimmune response is antigen-driven, that autoantigens are components of subcellular particles involved in important biosynthetic functions, and that the epitopes recognized by autoantibodies are active sites or functional domain regions of these antigens. An intriguing hypothesis is that activated intracellular particles are the immunogens that drive the autoimmune response.