IgG antibodies to SS-B (La), RNP/Sm and DNA are produced by PWM-stimulated normal human lymphocytes in culture.

Peripheral blood lymphocytes from five healthy subjects and three patients with Sjögrens syndrome and systemic lupus erythematosus were stimulated with pokeweed mitogen to examine the effects of polyclonal activation on the secretion of autoantibodies in health and disease. Antibodies to SS-B (La), RNP/Sm and DNA were detected in supernatants from cultures from healthy controls, in some cases approaching levels secreted by the patients. All secreted autoantibodies were of IgG class and the antigen specificity of the secreted anti-SS-B was proven by cross-adsorption experiments. Our results extend the range of defined specificities of autoreactive B cells in healthy individuals. These data argue against a case for physiological deletion of autoreactive B cell clones and support theories of their active recruitment in autoimmunity.