脳疾患における髄液中ミエリン塩基性蛋白（Myelin Basic Protein）の値—特に悪性脳腫瘍における変動

Myelin Basic Protein in the Cerebrospinal Fluid of Patients with Neurological Disease:especially with malignant brain tumors

I．はじめに

　髄液ミエリン塩基性蛋白（myelin basic protein，以下MBPと略す）は，髄鞘損傷との関係を示し，脱髄あるいは髄鞘におよぶ脳実質の損傷をうける組織の量を反映するといわれ，多発性硬化症の増悪時^3,4,10）や種々の脳神経疾患で上昇^{1,4-7,9,15-22）}することが知られている．しかしながら脳腫瘍に関する報告が殆どなく，種々の脳腫瘍におけるその値は，興味がもたれる．今回われわれは，70人の脳腫瘍の患者の髄液を可能な隈り経過を追って測定し，その他の脳疾患における髄液値と比較し，特に悪性腫瘍に対する治療における変動よりその有用性と治療におけるMBP測定の意義について検討した．

Myelin basic protein (MBP) in the cerebrospinal fluid (CSF) of patients with brain tumors and other neurological diseases was measured before, during and after various treatments such as surgery, chemotherapy and irradiation. We assessed the significance of changes in the MBP levels during the course of treatment, and speculate on what the elevated level of MBP in brain tumor patients indicates. In meningeal dissemination of malignant tumors, meningeal carcinomatosis from can-cer of the systemic organ showed the highest level of MBP followed by meningeal gliomatosis and meningeal lymphoma. Meningeal carcinomatosis and meningeal lymphoma, which have responded to chemotherapy, showed normal levels of MBP after chemotherapy. Six of eight patients with newly diagnosed malignantglioma showed moderate to high levels of MEP (range 4.6-35.5ng/ml) just before intraarterial chemotherapy with VP-16 and CDDP. The level increased in five pa-tients during the course of chemotherapy and then de-creased in relation to the degree of tumor reduction by chemotherapy. In the solid type of metastatic brain tumor, five of seven patients with multiple tumors showed high levels of MBP and these levels also re-turned to normal after treatment in four patients. As for the influence of irradiation, levels of MBP did not increase after irradiation except in three patients who developed radiation necrosis, local extensive ede-ma or atrophic change. In other brain tumors, levels of MBP were high in a patient with a large meningioma with very extensive edema and during an unstable post-operative condition after total removal of a large cra-niopharyngioma. However, benign tumors did not show abnormal levels of MBP in general, even though they were large. Other neurological diseases, hydrocephalus, bacterial meningitis and hemorrhagic infarction showed high levels of MBP, but the former two returned to normal after treatment. MBP reflects not only the severity of brain damage but also the effects of treat-ment. MBP may be a marker indicating the prognosis of disease. Cyst fluids of malignant glioma showed the highest levels of MBP and it is speculated that MBP may he derived front the tumor itself or the brain adja-cent to the tumor. The mechanism of MBP increase in malignant brain tumors should be studied further.