Helminth antigens were investigated in the search for accessible
heterologous antigens capable to discriminate different
helminthiases, by the
enzyme linked
immunosorbent assay (ELISA) and the immunoblot assay (IB).
Antigens used were: Taenia solium cysticercus total saline (Tso); Taenia crassiceps cysticercus vesicular fluid (Tcra-VF); T. crassiceps cysticercus
glycoproteins (Tcra-GP and Tcra-(18-14)-GP); Toxocara canis larva excretory-secretory (
TES); Schistosoma mansoni adult total saline (Sm) and Echinococcus granulosus hydatid fluid (Eg). The assayed sera were from patients with:
cysticercosis (n = 18);
toxocariasis (n = 40);
schistosomiasis (n = 19) and
hydatidosis (n = 50) with proven clinical and laboratory diagnosis, and sera from rabbits immunized with Tso, Tcra-VF,
TES and Eg. Cross-reactivity occurred mostly between
infections caused by Taenia and Echinococcus or in immunized rabbits, by ELISA. Moreover, the cross-reactivity among
helminthiases was found with the use of
antigens belonging to phylogenetically related parasite species, Eg, Tso and Tcra-VF, by sharing same antigenic components. Lower cross-reactivities were obtained by IB technique, when only
peptides were considered as
antigens, and the use of T. crassiceps purified
glycoproteins demonstrated high sensitivity and specificity in the diagnosis of human
cysticercosis, similarly to that using homologous
antigen (Tso) by the same technique.