Levels of astroprotein (an astrocyte-specific cerebroprotein) in cerebrospinal fluid of patients with brain tumors. An attempt at immunochemical diagnosis of gliomas.

Levels of astroprotein (an astrocyte-specific protein found in the cerebrum) were measured by radioimmunoassay in the cerebrospinal fluid (CSF) of 120 patients with intracranial diseases and eight control subjects. The astroprotein level was elevated (above 25 ng/ml) in 13 of 30 cases (43.3%) of glial tumors, nine of 57 cases (15.8%) of nongliomatous intracranial tumors, seven of 33 cases (21.2%) of non-neoplastic intracranial diseases, but in none of the eight control cases. In glioblastoma patients, CSF astroprotein was elevated in eight of 12 cases (66.7%), in three of them to a remarkable degree (above 500 ng/ml). The possible role of this test is briefly discussed, and the mechanism of increase of the astroprotein levels in the CSF considered.