Detection of lymphocytes in malignant gliomas by monoclonal antibodies.

Lymphocytes are not present in normal brain but are known to infiltrate malignant gliomas. The reasons for this infiltration and the signals involved are not understood. The lymphocyte content of 15 malignant gliomas removed at time of surgery was studied, using monoclonal antibodies to T and B cell surface antigens and immunofluorescence. An average of 41% of infiltrating cells possessed surface Ig, with 21% bearing the common T cell marker. There was no evidence of oligoclonal restriction of light chain types.