title: Widespread immunoreactivity for alpha-1-antichymotrypsin in different types of tumors.
abstract: The presence of alpha-1-antichymotrypsin (AACT) immunoreactivity was investigated in a broad range of different tumors. Because optimal AACT immunoreactivity of histiocytes was achieved by use of a protease pretreatment of paraffin sections, all tumors were studied by using pepsin treatment of the sections. In such conditions, more than 80% of different carcinomas, sarcomas, melanomas, and lymphomas were positive for AACT. The results indicate that AACT immunoreactivity is not specific for histiocytic tumors and therefore cannot be used as a histiocytic marker and to substantiate the concept of histiocytic nature of tumors, such as malignant fibrous histiocytoma. The concept of AACT as a histiocytic marker may be based on the fact that histiocytes, for some reason, stain more intensively for AACT, and immunoreactivity can also be found in them at unoptimal immunostaining conditions.
authors: Department of Pathology, University of Helsinki, Finland.
authors: Y
authors: Y
authors: Soini
authors: M
authors: M
authors: Miettinen
mesh_terms: D006644:Histiocytes / Q000276:immunology; D006801:Humans; D007158:Immunologic Techniques; D009369:Neoplasms / Q000276:immunology*; D012016:Reference Values; D013194:Staining and Labeling; D000514:alpha 1-Antichymotrypsin / Q000276:immunology*
chemical_list: D000514:alpha 1-Antichymotrypsin