Sera obtained from Chilean-hospitalized pediatric patients diagnosed with HUS, after STEC primoinfection, recognizes antigens such as OmpT, Cah and Hes, as a result of a primary immune response to an initial STEC antigen exposure with the development of immunological memory (sera obtained from the convalescent phase with IgG and IgA that recognize STEC antigens)13. This evidence concerns the gene CD79A and hemolytic-uremic syndrome.