Serodiagnosis of human neurocysticercosis using antigenic components of Taenia solium metacestodes derived from the unbound fraction from jacalin affinity chromatography

The aim of the present study was to analyse Taenia solium metacestode antigens that were derived from the unbound fraction of jacalin affinity chromatography and subsequent tert-octylphenoxy poly(oxyethylene) ethanol Triton X-114 (TX-114) partitioning in the diagnosis of human neurocysticercosis (NCC). Immunoassays were designed to detect T. solium-specific IgG antibodies by ELISA and immunoblot. Serum samples were collected from 132 individuals who were categorised as follows: 40 had NCC, 62 presented Taenia spp or other parasitic diseases and 30 were healthy individuals. The jacalin-unbound (J(unbound)) fraction presented higher sensitivity and specificity rates than the jacalin-bound fraction and only this fraction was subjected to subsequent TX-114 partitioning, resulting in detergent (DJ(unbound)) and aqueous (AJ(unbound)) fractions. The ELISA sensitivity and specificity were 85% and 84.8% for J(unbound), 92.5% and 93.5% for DJ(unbound) and 82.5% and 82.6% for AJ(unbound). By immunoblot, the DJ(unbound) fraction showed 100% sensitivity and specificity and only serum samples from patients with NCC recognised the 50-70 kDa T. solium-specific components. We conclude that the DJ(unbound) fraction can serve as a useful tool for the differential immunodiagnosis of NCC by immunoblot.