Characterization of allergens in Schistosoma mansoni, Fasciola hepatica and Echinococcus granulosus.

Various antigens interacting specifically with IgE antibodies from infected humans were identified in S. mansoni, F. hepatica and E. granulosus soluble extracts by means of radioimmunoelectrophoresis. Two allergens common to adult worm and cercariae were identified in S. mansoni extracts. They proved to be distinct from genus--or species--specific antigens previously identified in the parasite. In adult F. hepatica extract a species-specific antigen and another lipoprotein were shown to interact with IgE antibodies of patients with fasciolasis. Two major allergens were also found in whole fluid of sheep E. granulosus cysts. One of them corresponded to Echinococcus genus specific antigen. These results are discussed according to immunological findings in parasitic infections.