Determination of the glial fibrillary acidic protein in human cerebrospinal fluid and in cyst fluid of brain tumors.

The glial fibrillary acidic protein (GFAP) have been quantitatively determined in over 200 samples of liquid content of brain tumours and in cerebrospinal fluid (CSF) of cases with various tumours of the cerebral nervous system. For establishing the GFAP value, the rocket radioimmunoelectrophoresis was used. The studies were performed in three series of patients. The GFAP value of fluids from 26 cysts of both neoplastic and non-neoplastic type had a wide range of 0.6 microgram/ml to 40 micrograms/ml. Significant elevation of GFAP was usually recorded in fluid from cysts of anaplastic tumour with astroglial differentiation. In this series of 24 cases with various brain tumours, the GFAP value of the CSF ranged from 0.2 microgram/ml to 50 micrograms/ml. In gliomas, as in astrocytoma and glioblastoma, these values were on a higher level, of over 4 micrograms/ml. In other tumours and in cerebral lesions of other aetiology, the GFAP values were lower, below 3 micrograms/ml and 0.3 microgram/ml respectively. In another series of 32 patients with brain tumour treated surgically, a significant increase of GFAP (to 30 micrograms/ml) was noted in the CSF during the first week after operation, and that was always associated with an increase of the total protein of the CSF. During the second and third week after operation, when the total protein of the CSF was reduced to a normal level, the values of GFAP were still elevated, first of all in those cases of astrocytoma and glioblastoma which were not radically excised. These findings suggest that investigation of GFAP in the CSF of patients with brain tumour may be helpful in diagnosis and prognosis.