Assessment of antigenic fractions of varying hydrophobicity from Taenia solium metacestodes for the diagnosis of human neurocysticercosis

Abstract

Summaryobjective To evaluate the detergent and aqueous phases of crude saline extract (crude) of Taenia solium metacestodes extracted with Triton X-114, for the detection of immunoglobulin G (IgG) antibodies by enzyme-linked immunosorbent assay (ELISA) and immunoblot for the laboratory diagnosis of human neurocysticercosis.method Serum samples were collected from 138 individuals and tested; 40 were diagnosed with neurocysticercosis (NC; group 1), 58 presented other parasitic diseases (group 2) and 40 were apparently healthy (group 3).results The detergent phase showed only one dominant component (70-50 kDa), while the aqueous phase showed four (116, 110, 97 and 77 kDa) by silver staining. ELISA sensitivity and specificity were 92.5% and 84.5% for crude phase, 92.5% and 93.3% for detergent phase and 72.5% and 72.6% for aqueous phase.conclusions The immunoblot of the antigens confirmed the results obtained by ELISA. Detergent phase purified from T. solium metacestodes was an important source of specific peptides and was efficient in detecting T. solium metacestodes antibodies in serum samples. This phase can be used for detecting IgG antibodies to T. solium metacestodes in seroepidemiological investigations and in the diagnostic screening of NC patients.

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

“…The reaction was stopped by washing with distilled water and positive reactions were identified by the appearance of clearly defined bands. The relative molecular masses of the recognised bands were determined by comparison with molecular markers (Sigma) and the serum samples were considered positive when immunodominant components with a molecular weight of 50-70 kDa were recognised, according to Machado et al (2007).…”

“…The D and A phases were obtained from chromatography batches containing 6 mg of total protein from the J unbound fraction using TX-114 (Sigma), as described by Machado et al (2007). J unbound was diluted in 1.7 mL of Tris-buffered saline (10 mM Tris-HCl, pH 7.4, 150 mM NaCl) and 1% TX-114.…”

“…ELISA -ELISAs for all extracts were carried out according to Machado et al (2007). Briefly, polystyrene microplates (Interlab, Brazil) were coated with each extract at concentrations of 10 µg/mL in 0.06 M carbonate bicarbonate buffer, pH 9.6.…”

“…Immunoblot -Immunoblot assays were performed on all ELISA-reactive serum samples according to Machado et al (2007). Antigen preparations were subjected to electrophoresis and transferred to nitrocellulose membranes (0.45 µm, Sigma), as previously described by Towbin et al (1979), using a transfer apparatus (Omniphor, England).…”

“…Integral membrane proteins of an amphiphilic nature are recovered in the D phase and hydrophilic proteins are found exclusively in the A phase (Bordier 1981). T. solium metacestode proteins recovered in the D phase have shown good results by ELISA and immunoblot for the diagnosis of NCC, but antigens purified using this technique alone have also shown some cross-reactivity, especially with Echinococcus granulosus by ELISA (Machado et al 2007). …”