Ca2 and Ca3 new monoclonal antibodies evaluated as tumor markers in serous effusions

Abstract

Ca2 and Ca3 are new monoclonal antibodies of IgG1 class, directed against the Ca antigen, a mucustype glycoprotein expressed on the surface of a wide range of malignant human cells and certain specialized normal epithelia. These antibodies were produced by immunization with purified preparations of the Ca antigen. They were tested to assess their value in the diagnosis of malignant effusions. Immuno‐alkaline‐phosphatase staining was used. Smears of pleural and peritoneal effusions were chosen to show: (1) undoubted malignant cells of various types; and (2) mesothelial cells in effusions from cases in which cancer was not in question. The Ca2 antibody, at 1 in 20 dilution of the culture supernatant, was the most specific, giving no reactions with benign mesothelial cells from any of the 35 cases tested. Malignant cells were clearly stained in 35 of 40 cases of carcinoma or mesothelioma. The staining was negative in two cases of oat cell bronchial carcinoma, and in three of four cases of carcinoma of the colon. Ca3 gave similar, but somewhat stronger, reactions with carcinoma cells, but was less specific, reacting weakly with mesothelial cells in 8 of 35 benign effusions. Because the falsenegative reactions given by the Ca series of antibodies are to some extent complementary to those given by monoclonal antibodies directed against the carcinoembryonic antigen (CEA), a combination of Ca2 and anti‐CEA is recommended as a most useful addition to the normal cytologic examination of effusions.

A 72 kD trophoblast glycoprotein defined by a monoclonal antibody

“…Several antibodies have exhibited a similar pattern of reactivity with normal epithelial tissues, for example HMFG1 and 2 (Taylor-Papadimitriou et al, 1981; Wilkinson et al, 1984), and CA 1, 2 and 3 (Bramwell et al, 1985), but this has not limited their use in immunoscintigraphy (Pateisky et al, 1985) or diagnosis of neoplasia (Warr & Cruickshank, 1987). In this respect, 5T4 is reactive with tumour cell lines of a diverse, but select origin, including those of a developmental nature, such as choriocarcinoma and embryonal carcinoma.…”

Immunocytological staining reactions of anti-carcinoembryonic antigen, Ca, and anti-human milk fat globule monoclonal antibodies on benign and malignant exfoliated mesothelial cells.

“…Although this series included only a few benign cases, the staining reactions of these antibodies on benign cases has been documented previously.5 Human milk fat globule membrane antigen antibodies occasionally give a weak reaction on benign mesothelial cells but this can easily be disGhosh, Butler tinguished from the strong staining reaction observed on malignant mesothelial cells. Ca antigen positive benign mesothelial cells have been observed in a small number of cases but the staining reaction is weak.5 9 13…”

Epitope analysis of monoclonal antibody NCRC-11 defined antigen isolated from human ovarian and breast carcinomas

“…The antibody Cal (IgM) was prepared against wheat germ agglutinin-binding glycoproteins from cultured human laryngeal carcinoma H.Ep2 cells (Ashall et al, 1982). Ca2 (IgGI) and Ca3 (IgG1) were both prepared by immunization with the purified Cal-defined antigen (Bramwell et al, 1985).…”

“…glycoprotein (>400,000) and in this study, antigen preparations were isolated by immunoadsorbent chromatography from ovarian mucinous and ovarian serous cyst adenocarcinoma and from breast carcinoma. Other monoclonal antibodies, against products in normal human milk, and antibodies of the Ca series (Bramwell et al, 1985) reacted with all three antigen preparations. Tests involving epitope mapping were performed to probe the relationships of the various epitopes to that defined by the NCRC-11 antibody, and, of note, the three antigen preparations from different tumour sources were remarkably similar with respect to their relative levels of epitope expression and to their topographical distribution of epitopes.…”