ABSTRACT
Results obtained from studies using experimental animal model clearly showed that (1) A marker(s) for CCA does exist; 2) This marker is a glycoprotein with a molecular weight of 200 kDa; (3) It is produced and secreted in vitro by tumor cell lines; (4) It is highly immunogenic in mice and the MAb specific for this antigen is directed against the carbohydrate moiety; (5) This tumor antigen can be detected in serum and bile of tumor-bearing animals by a sandwich ELISA employing this MAb; (6) Kinetic studies show a gradual elevation of this antigen during tumor development; and (7) The elevation of this antigen can be detected at a time when no pathological changes have yet taken place, as judged by microscopic examination. Preliminary work from the human counterpart using human cholangiocarcinoma cell line showed promising results. CCA-specific antigen could be similarly identified and the MAbs produced were highly specific for this 160 kDa antigen.
Subject(s)
Animals , Antigens, Neoplasm/blood , Bile Duct Neoplasms/diagnosis , Bile Ducts, Intrahepatic , Cholangiocarcinoma/diagnosis , Cricetinae , Glycoproteins/analysis , Humans , Mesocricetus , Mice , Rabbits , Tumor Cells, Cultured , Biomarkers, Tumor/analysisABSTRACT
Monoclonal antibody-based enzyme-linked immunosorbent assay and DNA dot blot hybridization techniques were developed and evaluated for their potential in the detection of Opisthorchis viverrini. A mixture of IgG monoclonal antibodies specific for the 89 kDa metabolic product of O. viverrini was captured on a microtiter plate by rabbit anti-mouse IgG and used in a sandwich ELISA for the detection of soluble parasite antigen in the feces of patients with opisthorchiasis. As little as 0.1 ng of the antigen could be detected. A specific O. viverrini DNA probe was used in a dot blot hybridization of parasite DNA. The labeled probe could detect DNA released from as few as five O. viverrini eggs. Both approaches were highly specific for O. viverrini and their sensitivity appeared to be comparable with that of the classical parasitological method. Preliminary data obtained from a field trial showed that these two methods have potential in the diagnosis of opisthorchiasis. Moreover, the limited data currently available showed that it is possible to use these methods to detect the presence of O. viverrini metacercariae in naturally infected fish.