MYELIN BASIC-PROTEIN IN THE CEREBROSPINAL-FLUID OF PATIENTS WITH BRAIN-TUMORS

WE MEASURED THE level of myelin basic protein (MBP) in the cerebrospin al fluid (CSF) of patients with various kinds of tumors, including mal ignant tumors, using radioimmunoassay. The CSF had been obtained by lu mbar puncture through an Ommaya reservoir or a shunt device placed in the lateral ventricle. The level of MBP was high (> 4 ng/ml) in the pa tients with meningeal dissemination of malignant tumors, but in those who showed a good response to chemotherapy and/or radiation, it decrea sed or returned to the normal level, with improvement on the computed tomography and magnetic resonance imaging, cytological, general CSF, a nd neurological findings. Of seven malignant gliomas without CSF disse mination, six showed an elevated level of MBP before selective intra-a rterial chemotherapy with a combination of etoposide and cisplatin adm inistered via a microcatheter placed at A1, M1, P1-P2, and the basilar top. All CSF specimens obtained during the period of the intra-arteri al chemotherapy showed an abnormally high (> 4 ng/ml) level of MBP tha t exceeded the prechemotherapy level. The MBP level decreased or retur ned to normal in the patients with a good response to chemotherapy aft er intra-arterial chemotherapy. In some patients with multiple metasta tic brain tumors, the MBP level was elevated before treatment and retu rned to normal after treatment (surgical removal, chemotherapy, and/or irradiation) in all except one. Thus, there was a clear correlation b etween the timing of treatment and changes in imaging studies and MBP levels. Only 3 of the 18 patients who had received irradiation and dem onstrated no brain tumors on magnetic resonance imaging after radiatio n therapy showed an abnormal MBP level; one developed brain atrophy 1 month after chemotherapy and radiation therapy for multiple metastatic brain tumor, one had massive edema after the macroscopically total re moval of a recurrent anaplastic meningioma, and the other had necrotiz ing encephalopathy, which developed 6 months after the complete disapp earance of anaplastic astrocytoma by chemotherapy and radiation therap y. Patients with benign brain tumors generally showed a normal MBP lev el; only 2 of 22 patients, one with meningioma with very extensive ede ma and the other with an unstable postoperative condition after the to tal removal of a large craniopharyngioma, showed a high MBP level. The se findings suggest that the MBP level reflects not only brain damage in the acute stage but also the effect of treatment, including surgery , radiation, and/or chemotherapy, in malignant brain tumors.