title: Immunohistochemical demonstration of alpha-1-proteinase inhibitor in brain tumors.
abstract: Using light microscopy and immunoperoxidase methods (PAP), the presence of alpha-1-proteinase inhibitor (API) was studied in seventeen brain tumors and four normal brain samples. The brain tumors included four glioblastomas, five low-grade gliomas, two metastatic lung carcinomas, two acoustic schwannomas, and four meningiomas. Normal brain displayed a finely granular intracytoplasmic staining confined to neuronal cells. Glial cells were negative for API. Fifteen of the 17 brain tumors were positive for API. Only two of five low-grade gliomas were negative for API. Glioblastoma and metastatic tumors exhibited the strongest positivity followed by acoustic neuroma, meningioma, and low-grade glioma. All positive samples exhibited finely granular intracytoplasmic API, and 50% exhibited extracellular API positivity. Metastatic and glioblastoma tumors demonstrated prominent extracellular API staining. Our results support the concept of a local production of API by brain tumors.
authors.forename: M
authors.initials: M
authors.lastname: Zuccarello
authors.forename: R
authors.initials: R
authors.lastname: Sawaya
authors.forename: M B
authors.initials: MB
authors.lastname: Ray
mesh_terms: D001798:Blood Proteins / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism* / Q000556:secondary; D005910:Glioma / Q000378:metabolism*; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D008579:Meningioma / Q000378:metabolism*; D009464:Neuroma, Acoustic / Q000378:metabolism*; D011480:Protease Inhibitors / Q000378:metabolism*; D000515:alpha 1-Antitrypsin
chemical_list: D001798:Blood Proteins; D011480:Protease Inhibitors; D000515:alpha 1-Antitrypsin