Cross-reactivity between human hemopoietic cells and brain tumors as defined by monoclonal antibodies.

A battery of 24 monoclonal antibodies raised against human hemopoietic cells was tested in an indirect immunofluorescence technique on frozen sections of a variety of human neurogenic and non-neurogenic tumors. Twelve antibodies demonstrated some type of labeling of neurogenic tumors, frequently in patterns characteristic for benign and/or malignant gliomas and/or primitive neuroectodermal tumors (PNETs). Although also some cross-reactivity occurred in non-neurogenic tumors, the apparent operational specificity of some of our antibodies within the nervous system promises some aid in neuropathological tumor diagnosis; this was also demonstrated by combined use of some antibodies on smear preparations in which diagnosis by conventional stains was uncertain. This study confirms and expands previous data that sharing of antigenic determinants by hemopoietic cells and nervous system tumors is common. The significance of these cross-reactivities is at present a matter of speculation; cross-reacting autoantibodies might interfere with immune regulation in tumor patients, and an immune response might be initiated when glioma cells bearing Ia antigens present tumor-associated antigens to T cells.