MCAT and rheumatic fever: Unoperated ARF patients developed a cardiopathy following ARF; however, since they did not undergo valvular replacement, the disease was seemingly induced in them, and MT-CYB mutations were detected in the cells involved in the autoimmune response in blood, similar to T and B lymphocytes, and macrophages, since self-reactive T cells migrate from peripheral blood to the heart and proliferate in the valves in response to stimulation by specific cytokines [6].