Autologous humoral response to human gliomas and analysis of certain cell surface antigens: in vitro study with the use of microcytotoxicity and immune adherence assays.

In 25 patients with intracranial gliomas, the autologous humoral response was studied in vitro with the use of microcytotoxicity (MC) and immune adherence (IA) assays. Antibodies were detected to autologous cultures in 44% of the cases by MC and in 50% by IA. These positive responses occurred in statistically different groups of patients, which suggested that different functional types of antibody were involved. Direct testing and absorption experiments showed that antibody was not significantly directed against autologous fibroblasts. Autologous cytotoxic antibodies were detected by 67% of astrocytoma cases and in only 10% of patients harboring a glioblastoma, the most anaplastic tumor of the glioma series. By means of the IA assay, absorption experiments were performed with the use of adult and fetal brains and cultures of autologous and allogeneic gliomas and fibroblasts. In this serologic system, the types of antigenic expression of a human glioma could be categorized as follows: 1) highly restricted glioma antigen(s), 2) common glioma antigen(s), 3) neurectoderm-derived antigen(s), and 4) brain and fibroblast-associated oncofetal antigen(s). The common glioma antigen and oncofetal antigen appeared to be qualitatively different, and the glioma antigen was expressed in uncultured tumor tissue.