[Immunohistochemical studies of bronchial carcinoma using monoclonal antibody A63-C/A3].

: An immunohistological study was undertaken, using paraffin sections of 22 cases of lung carcinoma and a number of reference tissue samples, to clear up the reactivity of A63-C/A63 monoclonal antibody (IgM) which was capable of identifying a carcinoma-associated carbohydrate antigen. Following neuraminidase pretreatment of those sections, positive response to the above antigen was produced by more than 90% of all bronchial carcinoma samples, notwithstanding the histological type involved (squamous-cell carcinoma or adenocarcinoma). Columnar epithelium of the bronchi, not involved in the neoplastic process gave a positive immunoreaction with the antibody A63-C/A3 in 64% of the cases.