Sensitive determination of circulating anodic antigen in Schistosoma mansoni infected individuals by an enzyme-linked immunosorbent assay using monoclonal antibodies.

From a panel of mouse monoclonal antibodies reactive with a repeating epitope of the schistosome circulating anodic antigen, an IgG1 monoclonal antibody was selected. This monoclonal antibody was applied in a sandwich enzyme-linked immunosorbent assay as capture antibody and as alkaline phosphatase labeled conjugate. This assay allowed a sensitive quantitation of circulating anodic antigen in serum samples of infected individuals, detecting less than 1 ng antigen/ml serum. In Schistosoma mansoni infected individuals from Zaire, the level of antigen in serum correlated with fecal egg output. The lower detection level of the immunoassay corresponded to a level of about 10 eggs/gm feces.

Three monoclonal antibodies with specific binding activity to the excretory system of Schistosoma mansoni: an immunoelectron microscopic study using the gold labeling technique.

This study describes three monoclonal antibodies against the excretory system of Schistosoma mansoni. Immunofluorescence revealed antigens forming part of the excretory system of cercariae, adult worms, and miracidia, which were located on the luminal membranes of flame and first tubule cells by immunoelectron microscopy. These antigens are either structural components of the membranes or they derive from excretory fluid and are absorbed during transport and ultrafiltration. Binding specificity of the monoclonal antibodies was tested by immunoelectrophoresis and competitive immunofluorescence; one or two antigens were recognized by each. Reactivity of the antigens after treatment with 7.5% trichloroacetic acid or Rossman's fixative demonstrates at least partial polysaccharide content.