Cellular and humoral in vitro cytotoxicity against autologous bladder tumor cells in humans. Differences in autologous cytotoxicity against non-invasive and invasive transitional-cell tumors of the urinary bladder.

Lymphocyte-mediated cytotoxicity (LMC), antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) were measured in a 51Cr assay against autologous tumor cells from 7 patients with non-invasive and 9 patients with invasive transitional-cell tumors of the urinary bladder (TCC). Cytotoxicity against the invasive tumor cells were demonstrated in CDC. Heat-inactivation of sera lead to complete loss of cytotoxicity while addition of allogenic serum restored cytotoxicity. The cytotoxicity of allogenic sera from controls against invasive tumor targets showed no differences when compared with autologous sera. No or very weak cytotoxicity was found against non-invasive tumor targets in autologous or allogenic assays. LMC and ADCC showed weak or no reactivities. Intensive wash or trypsinization of effector cells did not affect the cytotoxicity in LMC. The results indicate the occurrence of complement-dependent antibodies directed against target cells from invasive tumors of the urinary bladder while no cytotoxic responses were detectable when the target cells originated from non-invasive tumors.