Levels of the schistosome circulating anodic and cathodic antigens in serum of schistosomiasis patients from Brazil.

Serum levels of 2 schistosome circulating antigens, the circulating anodic antigen (CAA) and the circulating cathodic antigen (CAA), were determined in persons infected with Schistosoma mansoni in Brazil. Sensitive monoclonal antibody-based enzyme-linked immunosorbent assays were used to measure levels of the 2 antigens. The study group consisted of 38 individuals with intestinal schistosomiasis, and 20 persons with the hepatosplenic form of the disease. Age and intensity of infection were comparable for the 2 groups. CAA was detected in 65.5% of all patients' sera and CCA was found in the serum of 82.8% of all patients. CAA levels correlated well with the egg output, as determined by duplicate Kato-Katz smears; CCA was significantly positively correlated with egg output in patients with intestinal schistosomiasis only. Whereas no significant difference was found between CAA titre in patients with intestinal schistosomiasis and those with the hepatosplenic form, a significantly higher CCA titre was found in patients with hepatosplenomegaly compared to patients with intestinal schistosomiasis.