Antibody-dependent cell-mediated cytotoxicity (ADCC) describes the cell-killing ability of certain lymphocytes, which requires the target cell being marked by an antibody. Lymphocyte-mediated cytotoxicity, on the other hand, does not have to be mediated by antibodies; nor does complement-dependent cytotoxicity (CDC), which is mediated by the complement system. Test of cytotoxicity can be done in vitro or in vivo. In vitro tests are done in cells. The agent is treated with the cells in various ratio, and the effect on morphology and cell viability is studied. The Lethal dose (LD50) can also be calculated.
Three groups of cytotoxic lymphocytes are distinguished:
