DIFFERENT ANTIGENIC PROFILES AND ENZYME-LINKED IMMUNOSORBENT ASSAY RESULTS BETWEEN ECHINOCOCCUS GRANULOSUS SENSUS STRICTO HYDATID CYST FLUIDS CLASSIFIED AS G1 AND G3 GENOTYPES

The objective of the present study was to investigate whether G1 and G3 genotypes of Echinococcus granulosus sensu stricto hydatid cyst fluid (HCF), are differently detected by Western blot and Enzyme-linked immunosorbent assay (ELISA) analysis, using sera from patients infected with the parasite and the detection of different IgG subclass antibodies.The main result was that antigen recognition depends on the genotype of HCF used as antigen, even though the G1 and G3 genotypes are classified within the same parasite species.The smallest antigens detected were on the 8-10 kDa range which may correspond to antigen B subunit.Statistically significant differences between G1 and G3 antigens were also detected by ELISA, but only using IgG4 subclass antibodies.Detection of G1 and G3 HCF depends also on IgG subclass antibodies.Thus, both with Western blot as well as ELISA significant differences were observed between IgG4 and either IgG2 or IgG3 subclasses.Taking into account our results and the literature, it is reinforcing the need for Western blot confirmation of ELISA and the detection of IgG1 and IgG4 subclass specific antibodies, in order to be sure that the serological results may not be changed by using HCF not classified as G1 genotype.