Usefulness of gel filtration fraction as potential biomarker for neurocysticercosis in serum: towards a new diagnostic tool

Abstract

There is an increasing interest in improving neurocysticercosis (NCC) diagnosis through the search of new and alternative antigenic sources, as those obtained from heterologous antigens. The aim of this study was to obtain potential biomarkers for NCC diagnosis after gel filtration chromatography [gel filtration fraction (GFF)] from the total saline extract (SE) from Taenia saginata metacestodes, followed by protein identification and application in immunodiagnostic. SE and GFF proteic profiles were characterized in gel electrophoresis, and diagnostic performance was verified by testing 160 serum samples through enzyme-linked immunosorbent assay and immunoblotting. Sensitivity (Se), specificity (Sp) and other diagnostic parameters were calculated. Polypeptides of interest in the diagnosis of human NCC present at GFF were analysed by mass spectrometry (MS) and B-cell epitopes were predicted. GFF had the best diagnostic parameters: Se 93·3%; Sp 93%; AUC 0·990; LR+ = 13·42 and LR- = 0·07, and proved to be useful reacting with serum samples in immunoblotting. Proteic profile ranged from 64 to 68 kDa and enolase and calcium binding protein calreticulin precursor were identified after MS. The enolase and calcium-binding protein calreticulin precursor showed 18 and 10 predicted B-cell epitopes, respectively. In conclusion we identified important markers in the GFF with high efficiency to diagnose NCC.

Neurocysticercosis serodiagnosis: mimotope-based synthetic peptide as potential biomarker

“…Some diagnostic tests to detect NC use crude antigenic preparations, which can result in low specific diagnostic tests due to cross-reactions with antigens from other helminthic species. New alternatives to circumvent the cross-reactivity associated with crude antigens, such as partly purified antigens (Nunes et al 2017) and recombinant (da Silva Ribeiro et al 2010) or synthetic peptides, are being developed. Some strategies used to obtain these biomolecules have a subtractive or a purification step in which cross-reactive antigens can be removed, resulting in minimal or no cross-reactivity, and therefore, improving the specificity for the diagnosis.…”

“…NC global burden is not precise due to the necessity of neuroimaging to confirm infection; in addition, there are problems with the sensitivity and specificity of diagnostic tests, since crude antigens cross-react with antigenic determinants shared with other helminths (Nash et al 2013). Focusing on these problems, several advances were made leading to the achievement of antigenic fractions (Nunes et al 2017), recombinant antigens (da Silva Ribeiro et al 2010;Noh et al 2014;Hernández-González et al 2017), and synthetic peptides (Noh et al 2014) applied to NC diagnosis.…”

Advances in the Diagnosis of Cysticercosis

“…There has been an increased interest in diagnosing NCC using new alternative antigenic sources because the presence or absence of antibodies cannot distinguish between different stages of the disease. A 2017 study by Nunes et al used protein purification and gel filtration chromatography to identify potential heterologous antigens in a T. s o l i u m metacestode [31]. The study sought to discover specific polypeptides of interest and B cell epitopes for diagnosing NCC using gel filtration fractions and mass spectroscopy.…”

The many faces of parasite calreticulin

“…Given this commonality, it is likely that Calr will be useful in the early detection of infection by T. britovi in endemic regions ( 139 ). An additional study performed predictions of the B-cell epitopes of TsCalr, which could potentially bind to antibodies and act as a serum biomarker for the diagnosis of neurocysticercosis ( 140 ). Furthermore, a recombinant form of Acanthamoeba castellanii Calr, the etiologic agent of granulomatous amebic encephalitis (GAE), was recognized by the sera of rats infected with GAE, highlighting its diagnostic capabilities ( 141 ).…”