Detection of antibody and complement complexed in vivo on membranes of human cancer cells by mixed hemadsorption techniques.

The mixed hemadsorption (MHA) techniques demonstrated antibody and complement fixed in vivo to the surface of human cancer cells. Tumors from 12 cancer patients and normal tissues from 5 cancer patients and 8 patients with cerebrovascular or cardiac diseases were collected from biopsy and autopsy for in vitro testing. Antiserum to human whole immunoglobulins and antiserum to human C3 were used in the MHA techniques. Positive MHA patterns were demonstrated on the surface of cancer cells by both methods. Positive reactions ranged from 12 to 32% in mixed hemadsorption for anitbody detection and from 10 to 34% in mixed hemadsorption for complement component 3 detection. Normal tissues obtained from cancer patients or from patients who died of causes other than cancer rarely exhibited distinct MHA reactivity. Collectively, the data suggest that most human cancers are antigenic in the autologous host and that tumor-associated antigens of cancer cells react in vivo with their humoral antibody to fix complement.