Detection and quantification of circulating antigen in schistosomiasis by monoclonal antibody. II. The quantification of circulating antigens in human schistosomiasis mansoni and haematobium: relationship to intensity of infection and disease status.

Circulating cathodic and circulating anodic antigens were quantified in sera of patients infected with S. mansoni, S. haematobium or both parasites. A monoclonal antibody and a polyclonal antiserum were applied in precipitation and solid phase immunosorbent techniques using radio- and enzyme-labelled antibody as a tracer to detect the cathodic and anodic antigen respectively. The results show that circulating cathodic antigen can frequently be detected in an immunoprecipitation or an immunoradiometric assay in serum of infected patients. The serum concentration of this antigen was found to be significantly correlated to the number of S. mansoni worms and to be higher in patients with the hepatosplenic form of the disease than in those without such complications. Examining paired serum samples before and after specific treatment the determination of this antigen by monoclonal antibody reliably indicated efficacy of chemotherapy in patients having received different forms of treatment.