Abstract
The characteristics of the antigens in larval flukes of Paragonimus westermani were examined. The agar gel double-diffusion test and competitive enzyme-linked immunosorbent assay, using the antiserum against the antigen extracted from larval flukes, showed cross-reactivity between the larval and adult antigens. In immunoblotting analysis, there was a decrease in reactivity of the antiserum absorbed with the adult fluke antigen against the band with a molecular weight of 26, 000. However, the bands corresponding to 34, 000 or higher molecular weights were still detected. The immunoperoxidase-staining technique revealed that the antigens reacting to the unabsorbed and absorbed antisera were both located on the surface of the gut epithelium and in the luminal contents of larval flukes. These results suggest that the extract of larval P. westermani possesses at least two antigens, originating probably from the gut, one being common to the adult and the other characteristic of the larva.
