Discordance among cell-mediated cytolytic mechanisms in cancer patients: Importance of the assay system

ADCC and SCMC directed against Chang cell targets that are mediated by lymphocytes having properties characteristic of K cells were impaired in cancer patients. In contrast, ADCC directed against CRBC targets that is mediated by both K cells and macrophages was normal in cancer patients, whereas SCMC against CRBC that is mediated primarily by macrophages was increased. Thus, there was a discordance among cytotoxic mechanisms in cancer patients with K cell-mediated cytotoxic function being impaired and macrophage-mediated cytotoxicity being enhanced. Regression analysis suggested that these perturbations of cytotoxic function occurred independently. Cancer patients had an increased proportion of circulating macrophages and a decreased proportion of eosinophils, but these abnormalities did not correlate significantly with ADCC or SCMC.