Glial fibrillary acidic protein and its fragments discriminate astrocytoma from oligodendroglioma

In the last few years it has been shown that anaplastic oligodendrogliomas, in contrast to anaplastic astrocytomas, are responsive to a three drug regimen chemotherapy. The histologic criteria for the discrimination between oligodendrogliomas and astrocytomas are subject to substantial interobserver variability, particularly in anaplastic and mixed gliomas. In the present study a two-dimensional electrophoresis technique (2-DE) has been applied to glioma samples in an attempt to discriminate the glioma subtypes. It was found that the presence of glial fibrillary acidic protein (GFAP) fragments distinguishes oligodendroglioma from astrocytoma. One-dimensional (1-DE) immunoblots were compared with immunohistologically stained tissue sections in which various GFAP-positive cell types were seen. It is concluded that 2-DE and 1-DE GFAP immunoblotting provide accurate information for the reliable discrimination of anaplastic astrocytomas and oligodendrogliomas.