Immunochemical analysis of glial fibrillary acidic protein as a tool to assess astroglial reaction in experimental C6 glioma.

In experiments on Wistar rats with experimental C6 glioma, the immunohistochemical features of the astroglial reaction over 30 days after implantation were characterized. The formation of a glial border consisting of GFAP-positive reactive astrocytes at the periphery of C6 glioma was observed on postimplantation day 3 and until the death of the experimental animals. Reactive astrocytes encompassed not only the primary gliomal focus, but all tumor invasion foci. Quantitative assessment of astroglial reaction around glioma was carried out with immunofluorescent assay of glial fibrillary acidic protein (GFAP) on cerebral sections. The size of glioma and necrotic foci were analyzed morphometrically in parallel with enzyme immunoassay of serum GFAP. A correlation between morphometric indices of glioma and serum level of GFAP was found. It was concluded that serum concentration of GFAP correlated with the size of intracranial glioma, necrotic foci, and most strongly with the degree of reactive astrogliosis. Monitoring of the level of serum GFAP can serve as an additional diagnostic index reporting the state of intracranial glioma.