Demonstration of species-specific and cross-reactive components of hydatid cyst fluid antigens

ABSTRACT

ELISA-hydatid cyst fluid antigen [HCF-Ag-ELISA] and conventional echinococcosis IHAT were assessed for cystic hydatid disease [CHD] confirmed by HCF-Ag immunoblotting assay. The sensitivity of the tests was 94.4% and 83.3% for HCF-Ag-ELISA and IHA, respectively. HCF-Ag-ELISA showed some cross reactions in tumor cases [5.5%], but no cross reaction was observed in rheumatoid arthritis patients. IHA showed 100% specificity. To confirm this data, SDS- PAGE immunoblotting using HCF-Ag was applied. Echinococcus specific reactions were reported with 44 Kda, 34 Kda, 29 Kda and 8 Kda HCF-Ag resolved bands. A cross reaction was found with 27 Kda, 21 Kda, 16 Kda and 13 Kda bands in tumor patients. Moreover, a cross reaction was found with 200 Kda, 175 Kda, 62 Kda, 52 Kda and 40 Kda in serological anti-schistosoma antibodies positive cases. So, using specific HCF-Ag immunoblotting provided 100% sensitivity and specificity in CHD