A highly sensitive method for the demonstration of carcinoembryonic antigen in normal and neoplastic colonic tissue

Abstract

A highly sensitive method for the immuno-histochemical localisation of carcinoembryonic antigen (CEA) is described. This method is based on the binding of a peroxidase-antiperoxidase complex (PAP) to anti-CEA antibodies by means of an anti-gamma-globulin which reacts with both the anti-CEA and the antiperoxidase antibodies. Using the technique described here, CEA was localised in conventionally processed normal and cancerous colonic tissue. In normal as well as in neoplastic tissues, a CEA-specific staining of cell membranes and cytoplasm was demonstrated. In frozen sections of normal colonic tissue CEA was found even at high dilutions of the first antibody; this indicates the high sensitivity of the method. The applicability of the method to conventionally processed and thereby well preserved tissue specimens opens the possibility to identify CEA by light microscopy even at very low concentrations.

Immunohistochemical localization of carcinoembryonic antigen in adenocarcinoma of the endocervix and the endometrium.

“…Immunohistochemical study was performed by the ABC method (Hsu et al 1981) using Vectastain rabbit IgG kit (Vector Laboratories). Anti-CEA rabbit antiserum (Dakopatts) was absorbed with perchloric acid extract of normal human spleen tissue for 12 hr at 4°C before use to remove reactivity with non-specific cross-reacting antigen (Wagener et al 1978). Endogenous peroxidase activity was blocked with 0.3% hydrogen peroxide in anhydrous methanol.…”

Correlação entre o padrão de expressão tecidual e os valores séricos do antígeno carcinoembrionário em doentes com câncer colorretal

“…O CEA é formado por um conjunto de glicoproteínas semelhantes, pertencentes à família das imunoglobulinas, com peso molecular de 200 kDa, cuja principal função é promover a adesão intercelular 4,5,18 . Trata-se de glicoproteína produzida por tumores originários do tecido endodérmico, em especial os da mucosa do cólon, que possui determinantes antigênicos localizados na fração protéica da molécula formada por cadeias polipeptídicas simples, sendo o componente carboidrato composto principalmente por frutose, manose, galactose, N-acetilglucosamina e Nacetil-galactosamina 4,6,[19][20][21][22] .…”

“…O CEA é uma imunoglobulina cuja principal função é promover a adesão molecular intercelular 3,4 . Pesquisas que utilizam técnicas imunoistoquímicas revelaram que o CEA é um antígeno habitualmente presente nas células da mucosa cólica normal e nas do carcinoma colorretal 5,6 . A principal diferença entre o conteúdo de CEA nas células normais e neoplásicas aparenta ser muito mais quantitativa do que qualitativa 6 .…”

Immunohistochemical Localization of Carcinoembryonic Antigen(CEA) in Squamous Cell Carcinoma of the Uterine Cervix: Prognostic Significance of Localization Pattern of CEA.

“…Immunohistochemical study was performed by peroxidase-antiperoxidase (PAP) method (Sternberger 1979). Anti-CEA rabbit antiserum (Dakopatts/Kyowa Medex; Tokyo) was absorbed with perchloric acid extract of normal human spleen tissue for 12 hr before use to remove reactivity with nonspecific cross-reacting antigen (NCA) as reported by Wagener et al (1978). Endogenous peroxidase activity was blocked with 0.3% hydrogen peroxide in anhydrous methanol.…”