Excretory-secretory antigenic components of Paragonimus heterotremus recognized by infected human sera.

Antigenic components of Paragonimus heterotremus metabolic products were revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analysis of sera from patients with P. heterotremus infection, from patients with other illnesses, and from healthy adults. By SDS-PAGE, it was found that the metabolic products comprised more than eight major polypeptides. Immunoblot analysis revealed 11 components which were strongly recognized by paragonimiasis antisera. These antigenic components had molecular masses ranging from less than 12.3 kDa to 144 kDa. One antigenic band of 31.5 kDa was found to give a consistent reaction with paragonimiasis antisera (97% sensitivity). Of the other patient sera, only sera from patients with Fasciola sp. infection reacted with antigenic bands of 56, 38, and 18.5 kDa. The present findings suggest that the 31.5-kDa component is sensitive and specific for the diagnosis of human P. heterotremus paragonimiasis.