Immune responses in human colon cancer. II. Cytotoxic antibody detected in patients' sera.

Complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), and spontaneous cell-mediated cytotoxicity (SCMC) were evaluated in patients with colon cancer with the use of a 51Cr release microcytotoxicity assay. We studied the sera and peripheral blood lymphocytes (PBL) from patients with colon cancer as well as from normal controls using three separate human colon cancer cell lines as targets. Antibody active in either the CDC or ADCC assay was detected in 11 of 14 (79%) patients with colon cancer, but none was found in 18 normal individuals. The ability of PBL from patients with colon cancer and from normal controls to mediate ADCC and SCMC did not differ significantly.