Secondary allograft rejection is mediated by?

Secondary rejection (accelerated rejection) After hyperacute rejection, transplantation of a second graft, which shares a significant number of antigenic determinants with the first one, results in a rapid (2-5 days) rejection. It is due to the presence of T lymphocytes sensitized during the first graft rejection memory cells). Accelerated rejection is mediated by immediate production of lymphokines, activation of monocytes and macrophages, and induction of cytotoxic lymphocytes.