Markers in form of
tumor-associated
antigens have been identified in a variety of human
tumors including those of the central nervous system. As their
biological function is not yet clear, they are detectable at present only by various immunological means. Immunodiffusion, counter-current electrophoresis, immunofluorescence, and radioimmunoassays have been used to investigate sera of patients with
gliomas and other intracranial
tumors for the presence of circulating
antibodies directed against
glioma-associated
polypeptides. In our own studies, 75% of the
glioma patients' sera contained cross-reacting
antibodies, whereas sera from a variety of
cancer patients with diseases other than
glioma, as well as from patients without
cancer, were negative in this respect. These circulating
antibodies were used to monitor the course of the disease in
glioma patients undergoing
chemotherapy. A correlation between the antibody titer and the extent of the disease, as revealed by computer tomography, could be observed. Our findings are comparable with a variety of other reports on
glioma-associated
antigens, including
astrocytin and
malignin. Finally, the specificity of these
tumor markers as well as the sensitivity of their detection test will be evaluated with respect to their clinical utility.