Effect of operation and radiotherapy on antibody-dependent cellular cytotoxicity.

A subpopulation of human lymphocytes bearing receptors for the Fe portion of IgG causes lysis of nucleated target cells in the presence of antibody. The reaction is known as antibody-dependent cellular cytotoxicity (ADCC) and the effector cells have been called killer (K) cells. We have measured K cell activity quantitatively in the peripheral blood of cancer patients using 51Cr labeled murine mastocytoma target cells and hyperimmune rabbit antimastocytoma antibody. ADCC was the same in males and females, was not affected by eating, smoking or the presence of infections, but was decreased in those over 65 years, during pregnancy, and in those with cachexia, or severe sepsis associated with nonmalignant diseases. It was normal in those with cancers being treated for cure and in those with benign diseases, but was decreased in those with advanced cancers. Operation did not produce a significant change in those who were not immunodepressed; in those who were immunodepressed before operation it caused a significant decrease maximal by the fifth day with recovery by the 15th day. Radiotherapy caused a decrease in K cell activity, maximal at 4 weeks, that persisted for 12 weeks with recovery after that time in those who did not have residual tumor. The values did not return to normal in those who had persistent tumor or distant metastases.