<prompt> Streptococcal cross reactivity affects which organ?HeartSkinJointAll of the above  <response>: Ans. is d i.e. All of the above Non-supporative complications are due to antigenic cross-reactivity of streptococcal antigenic component with human tissues. This antigen cross reactivity is resoponsible for the production of cross reacting antibodies, i.e. antibodies are formed against streptococcal antigens but they damage host tissue antigens because of similarity between streptococcal antigens and human tissue antigens - antigenic cross reactivity.Streptococcal componentHuman tissueCapsular hyaluronic acidSynovial fluidCell wall proteinMyocardiumGroup A carbohydrateCardiac valvesCytoplasmic membrane antigenVascular intimaPeptidoglycansSkin antigens 