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.
Memory cells
Antibodies
Immune complexes
None of the above