第VIII因子関連抗原の免疫組組学的検討—正常脳，グリオーマおよび血管系腫瘍について

IMMUNOHISTOCHEMICAL LOCALIZATION OF FACTOR VIII-RELATED ANTIGEN IN NORMAL BRAIN, GLIOMA AND VASCULAR TUMORS

　抄録　第VIII因子関連抗原（VIII R：Ag）の局在を正常脳5例，グリオーマ14例，血管系腫瘍26例を中心に酵素抗体間接法により検索した。VIII R：Agはすべての脳実質，脈絡叢，くも膜下腔，硬膜静脈洞などや末梢神経組組で，広汎に血管内皮細胞に一致して検出された。一般諸臓器でも同様であった。グリオーマの反応性増生血管の内皮細胞も陽性で，またglornerurus様構造では陽性細胞と陰性細胞の混在がみられた。血管系腫瘍のうち，hemangioma 6例中4例で大多数の，2例で少数の内皮細胞で陽性であった。Hernan—gioblastoma 10例では，内皮細胞に限局して多数に陽性であったが，stroma cellはすべて陰性であった。Hemangioendothelioma 6例のうち，明瞭な管腔形成を示す分化した症例では多数の細胞に，他方，未分化な症例ではより少数の細胞に陽性であった。Hemangiopericytoma 4例では内皮細胞のみが陽性で，実質紬胞はすべて陰性であった。以上より，VIII R：Agは正常，反応性および腫瘍性内皮細胞で検出されることが示され，さらに管腔形成のより明瞭な血管系腫瘍ではより多数の陽性細胞を示したことから，VIII R：Agの形質発現が腫瘍性内皮細胞の分化度と密接に関連していることが示唆された。

Using formalin-fixed and paraffin-embedded sections, the localization of the factor if-related antigen (VIII R : Ag) was examined by the indirect immunoperoxidase method in 5 normal nervous tissues, 14 gliomas, and 26 intra-and extracranial vascular tumors. Various visceral organs were also examined in parallel.

In the normal nervous tissues, immunostaining for VIII R : Ag was confined to endothelial cells of arteries, veins and capillaries throughout the entire central and peripheral nervous systems. It was also true in the choroid plexus and meningeal tissues in which endothelial cells of the dural sinus were stained as well. In the visceral organs,positive staining was noted in endothelial cells, megakaryocytes, platelets and some lymphatic endothelial cells, in agreement with the previous works.

On examination of glioma tissues, similar stain-ing was noted in endothelial cells of hyper-plastic blood vessels. Occasional hypertrophic cells were stained intensively. In glomerulus-like structure, staining was usually observed in the cells forming vascular channels, but not in other coexistent cells, suggesting a difference in origin between these cells.

Positive staining was also observed in varying degrees in neoplastic endothelial cells of vascular tumors. Usually positive cells were frequent in hemangiomas and hemangioblastomas. Staining was noted only in endothelial cells, but not in other cells including stromal cells of hemangio-blastomas. In hemangioendotheliomas, positivecells were present more frequently in the cases of showing more distinct angiomatous pattern and/or vascular tubes, which are histologic indica-tions of tumor differentiation. Positive cells were present in these architectures and, though less frequently, scattered in the fields of randomly oriented cells. No positive staining was observed in parenchymal cells of hemangiopericytomas.

In summary, VIII R : Ag was present in normal and hyperplastic endothelial cells of the central and peripheral nervous systems. The antigen was also detected in a variable number of neoplastic endothelial cells of vascular tumors. As a whole, a larger number of positive cells were observed in tumors showing vascular formation than in those lacking this nature. It suggests the correla-tion between expression of VIII R Ag and grade of tumor differentiation.