Cysticercosis: IgG-ELISA evaluations of peak1 antigen and <30 kDa antigen of delipidized extract of Taenia solium metacestodes

Abstract

The antigenicity of ether-delipidized Taenia solium metacestode extract (DLPAg) was investigated by IgG-ELISA. The antigen showed higher antigenicity than that of non-delipidized antigen (NDLPAg). Then the DLPAg was subjected to Sephacryl S-200 gel chromatography and a partially purified antigen (DLPP1Ag) was identified as the promised antigen by IgG-ELISA using 25 sera from cysticercosis cases, 177 cases of 24 heterologous infections, and healthy controls. Sensitivity was 52% and specificity was 91.8% at the cut-off value (X̄+ 7SD), 0.399. Cross-reactivity occurred with 17 cases of eight diseases: cystic echinococcosis (7/11), taeniasis (1/16), gnathostomiasis (2/8), strongyloidiasis (1/12), angiostrongyliasis (1/12), paragonimiasis heterotremus (2/15), opisthorchiasis (1/9) and fascioliasis (2/7). When DLPP1Ag was fractionated through Ultra free centrifugal tube (retained 30 kDa) and Amicon (PM10), MWCOP1Ag (<30-10> kDa) was obtained; the antigen showed better results than DLPP1Ag with 88% sensitivity and 95.6% specificity at the cut-off value (X̄ + 4SD), 0.264. Nine cases of six diseases cross-reacted with this antigen: cystic echinococcosis (2/ 11), gnathostomiasis (2/8), trichinellosis (2/12), toxocariasis (1/5), schistosomiasis (1/6), and fascioliasis (1/7). MWCOP1Ag gave higher sensitivity than that of DLPP1Ag but some cross-reactivity occurred.