Detection of Schistosoma japonicum antigen (Sj31/32) in sera of Chinese patients using a sandwich ELISA based on monoclonal antibody.

A sandwich-ELISA was developed using IgG from rabbits infected with Schistosoma japonicum as capture antibody and a monoclonal antibody as detecting reagent for circulating Sj 31/32 in patient sera. The assay detected circulating antigen in 36 of 53 sera from Chinese schistosomiasis japonica patients, but not in sera from healthy persons or patients with paragonimiasis, trichinosis or cysticercosis. This is the first demonstration that Sj 31/32 proteins may be used for circulating antigen-based serodiagnosis of schistosomiasis.