Mononuclear cell infiltration in central portions of human astrocytomas.

The mononuclear cell infiltration in the central portion of human low- and high-grade astrocytomas has been examined using monoclonal antibodies to cell surface differentiation antigens. There was no significant difference between the number of T cells, B cells, or macrophages. The OKT8+ (suppressor/cytotoxic) T cell population was the major lymphocyte subset in the infiltrates. There was, however, indirect evidence for a proportion of the total OKT8+ cells being natural killer cells. Overall, there was a significant difference in the number of macrophages compared to the total lymphoid cell population. Several cell types seem to play an equal role in the cellular and humoral immune response within the center of the tumors, as distinct from that occurring at the periphery.