Antibodies to Echinococcus granulosus Egg Antigens in Hydatid Patients: Characterization by Immunoblot and Diagnostic Value

Cystic echinococcosis/hydatidosis, caused by Echinococcus granulosus, is a chronic zoonotic larval cestode infection in humans. Human hydatidosis is a public health parasitic disease that is cosmopolitan in its distribution. Several years may last between contamination with E. granulosus eggs and development of symptomatic cysts. Antigens expressed by embryos at early differentiation steps between the embryo and the young cyst may be interesting as markers of early infection or reinfection. This study investigates antibody response (IgG) to E. granulosus egg antigens by Immunoblot (IB) and ELISA in 20 hydatid patients surgically confirmed. We have also tested sera using protoscoleces and hydatid cyst fluid (HCF) from E. granulosus. The results show that hydatid patients reacted to eggs as well as protoscoleces and HCF. However, eggs share antigens in common with other life-cycle stages, but also support the notion that they may possess some unique stage-specific antigens determinants. The possible functional significance and the potential use of combined assessment of these antigens in IB with Ig G response in ELISA are discussed.