[Detection of a circulating SJ 70 antigen in human schistosomiasis japonica using a monoclonal antibody].

A double antibody enzyme-linked immunosorbent assay (sandwich ELISA) was used for detection of a circulating antigen from human Schistosoma japonicum infections. This assay involves the use of poly clonal rabbit anti-schistosoma japonicum soluble egg antigen (SEA) antiserum to bind circulating antigen and a monoclonal antibody (MCAb-H4) to identify and quantify this antigen. Sera from 108 S. japonicum infected patients (acute and chronic) were tested. Sera from 93 of 95 (98%) patients with chronic infection were positive for this antigen; sera from 12 of 13 patients (93%) with acute infections were also positive. Antigen was not detectable in control human sera. Sera from 35 chronic schistosomiasis patients were collected between 6 and 12 months after paraziquantel treatment. Circulating antigen was not detectable in the sera from 33 of these patients (94%) and was dramatically reduced in the other two patients.