Natural hidden autoantibodies react with negatively charged carbohydrates and xenoantigen Bdi

Immunoglobulin preparations from sera of healthy donors contain polyspecifi c autoantibodies interacting with DNA and other charged antigens. These ant ibodies belong to the IgG class and can exist in the free or hidden state. The hidden antibody activity can be revealed after ion-exchange chromatogra phy on QAE-Sephadex A-50. Immunoenzyme assay was used to assess the interac tions of both free and hidden antibodies with different carbohydrates. The hidden antibodies were only able to interact with different polyanionic car bohydrates and neutral xenoantigen Bdi.