IgG class antibodies from psoriasis patients recognize the 60-KDa heat-shock protein of Streptococcus pyogenes.

Background: We have previously found that psoriatic patients have IgG autoantibodies that recognize lesions but not autologous normal skin. The reactivity of the autoantibodies can be adsorbed with streptococcal antigens.

Methods: IgG antibodies were determined by immunoblot and ELISA to streptococcal antigens and by ELISA to the recombinants HSP60Sp, HSP70Sp, HSP60Ec and HSP60Hu, in plaque (PP) and guttate (GP) psoriasis patients, in healthy subjects (HC) and in individuals with streptococcal throat infections and high ASO titers, but without history of dermatological disease (ISp).