Lack of specificity of lymphocyte-mediated cytotoxicity against the bladder cancer cell line, T24.

We evaluated in vitro lymphocyte-mediated cytotoxicity against the T24 transitional carcinoma cell line and a control melanoma cell line (H894) in a double-blind study involving 25 bladder cancer patients, 19 patients with non-transitional carcinoma and 9 patients with benign conditions using a tritiated proline-labeled tumor cell assay. We found selective reactivity against T24 cells in 16 per cent of bladder cancer patients, 11 per cent of patients with non-transitional cell tumors and 22 per cent of patients with benign conditions. We found no significant differences with respect to the patterns of cytotoxic reactivity among the various patient groups. The use of different methods of lymphocyte purification and different lymphocyte to target cell ratios did not enhance the degree of specificity observed. Prior exposure to alloantigens did not account for the lack of specificity.