Immunocytochemical study of macrophages and microglial cells and extracellular matrix components in human CNS disease. 1. Gliomas.

We have used an immunocytochemical approach to investigate the inter-relationships between astrocytes, macrophages and microglia and the extracellular matrix components fibronectin and laminin, in 27 gliomas. Using recently available markers to macrophages and microglia (monoclonals Mac387, KP1 and the lectin RCA-1) and antisera to GFAP, fibronectin and laminin, we have described the reactions of these cells and the extracellular matrix. We found RCA-1 to be the superior marker for detecting most macrophages and microglia. There were more macrophages and microglia in high-grade gliomas than in low-grade. RCA-1 also reacted with endothelial cells in normal and reactive brain but showed markedly less affinity for endothelium in an close to gliomas. A possible role for the extracellular matrix in the astrocyte, macrophage and microglial reactions is discussed in the broader context of their role in the immune response.