Natural killer and antibody-dependent cell-mediated cytotoxicity activities and large granular lymphocyte frequencies in Viscum album-treated breast cancer patients.

20 breast cancer patients received a single intravenous infusion of Iscador, a mistletoe (Viscum album L.) extract. Natural killer (NK) and antibody-dependent cell-mediated cytotoxicity (ADCC) activities as well as the number of large granular lymphocytes (LGL) were investigated in their peripheral blood at various times. Six hours after the start of the infusion, significant decreases and 24 h later, significant increases in NK/ADCC activities and LGL frequencies were observed. These responses followed a kinetic pattern similar to that which has been described by others to occur after treatment with interferon.