In vitro generation of cytotoxicity against autologous human tumour biopsy cells.

Blood lymphocytes from 22 cancer patients were examined for cytotoxicity against autologous tumour cells in a short-term 51Cr release assay. Only three showed reactivity. In an attempt to increase cytotoxic potential in these and induce reactivity in non-reactive cases, the lymphocytes were cultured alone or with autologous tumour cells for 6 days. Upon subsequent testing against frozen, stored targets, nine samples reacted, including two of those with primary reactivity. In seven cases augmented cytotoxicity was evident in mixed cultures compared with lymphocytes cultured alone. Two of 10 cases showed cytotoxicity against the K562 cell line after culture and, in two of 13 tests in which allogeneic tumour biopsy targets were used, weak reactivity was bound. Cytotoxicity for autologous tumour biopsy cells was uniformly accompanied by positive blastogenesis in MLTI assays. In four cases blastogenesis occurred without the induction of cytotoxicity.