Immunostaining for alpha 1-antichymotrypsin and alpha 1-antitrypsin in gliomas.

Antisera to alpha 1-antichymotrypsin, alpha 1-antitrypsin and lysozyme were reacted with 20 cases of glioblastoma multiforme, seven anaplastic astrocytomas, eight astrocytomas, six oligodendrogliomas, four ependymomas and the cerebral cortex from six normal autopsy brains. In addition, two pleomorphic xantho-astrocytomas and two heavily lipidized malignant gliomas were similarly examined. All astrocytic lesions were confirmed with anti-GFAP antisera. Thirty astrocytic tumours (77%), four oligodendrogliomas (67%) and three ependymomas (75%) reacted positively with anti-alpha 1-antichymotrypsin; 25 astrocytic tumours (64%), three oligodendrogliomas (50%) and three ependymomas (75%) showed positive staining for alpha 1-antitrypsin. The pattern of staining with either of these two markers did not correlate with tumour grading. None of the gliomas examined stained positively with anti-lysozyme. Non-neoplastic glial elements did not react with any of the three antisera. The results of this study suggest that staining for alpha 1-antichymotrypsin and alpha 1-antitrypsin is of little value in the differential diagnosis of neuroepithelial or mesenchymal lesions in the brain.