Immunohistochemical Expression of Alpha-1-antitrypsin in Human Gliomas

Using light microscopy and the peroxidase-antiperoxidase (PAP) method, 41 human gliomas were subjected to immunohistochemical staining for alpha-1-antitrypsin (AAT), a major proteinase inhibitor. The specimens comprised 12 astrocytomas, 14 anaplastic astrocytomas and 15 glioblastomas multiforme. AAT was localized mainly in the cytoplasm of glioma cells and partially in the extracellular space. No staining was apparent in the endothelium of tumor vessels. The cytoplasm of neurons in normal brain tissue also positive for AAT. The frequency of tumor cells positive for AAT increased in proportipon to the degree of histological malignancy of glioma. The intensity of staining for AAT in the extracellular space also increased in proportion to histological malignancy. The AAT was considered to be derived from the tumor cells. Poor prognosis in patients with glioma was also correlated with the degree of AAT positivity. Therefore, staining for AAT in human glioma is useful for the prediction of histological malignancy and also for assessing the prognosis of patients.

Alpha-1-antitrypsin

神経膠腫

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