Antibody-dependent Cellular Cytotoxicity with Platelets As the Target Cell: Potential Application to the Study of Immune Thrombocytopenia

Antibody-dependent cellular cytotoxicity (ADCC) with platelets as the target cell is demonstrated with white blood cells, platelets and anti-platelet antibody obtained from marmosets. Greatest ADCC activity was observed with cell populations enriched for polymorphonuclear (PMN) cells and adherent cells. Non-adherent cells and lymphocytes obtained from blood pretreated with carbonyl iron showed a lower yet significant degree of activity. The virtual absence of PMNs and monocytes from these preparations indicates that a non-phagocytic-mediated destruction of platelets can occur by an ADCC process. Platelets having IgG deposited on them as a consequence of an autoimmune reaction following an interspecies platelet immunization are not necessarily susceptible to lysis by an ADCC mechanism. The ADCC reaction system as described and the results obtained suggest one can monitor platelets, effectors and soluble factors from immune thrombocytopenic patients and animals with respect to this mode of destruction in vivo.