Specific Taenia crassiceps and Taenia solium antigenic peptides for neurocysticercosis immunodiagnosis using serum samples

Abstract

Neurocysticercosis (NC), i.e., the presence of the larval form of Taenia solium in tissues, is the most frequent and severe infection involving the central nervous system. Paired serum and cerebrospinal fluid (CSF) samples from patients with NC, CSF and serum samples from a control group, and serum samples from patients with other parasitoses were studied by enzyme-linked immunosorbent assay (ELISA) and by immunoblotting with Taenia crassiceps vesicular fluid antigen (Tcra) and Taenia solium total saline antigen (Tso) for the detection of immunoglobulin G antibodies. ELISAs carried out with the Tso and Tcra antigens showed 94.1 and 95.6% sensitivities, respectively, for the detection of antibodies in CSF and 70.6% and 91.2% sensitivities, respectively, for the detection of antibodies in serum, with 100% specificity for the detection of antibodies in CSF and 80% specificity for the detection of antibodies in serum for both antigens. On the basis of the reactivities of the peptides in the samples analyzed, the peptides of </=23, 39, 85 to 77, and 97 kDa were found to be Tso specific by immunoblotting and the peptides of </=62, 74, 109, 121, and 131 kDa were found to be Tcra specific. Tests with Tcra extract had higher sensitivities and more homogeneous results and permitted us to obtain the parasites easily. We suggest the use of Tcra ELISA for the study of serum and confirmation of the results for sera positive by an immunoblotting analysis in which specific peptides (e.g., peptides of 19 to 13 kDa) are detected.

FIG. 1

Results for CSF (a and b) and serum (c and d) samples from patients with NC (P) and for serum samples in group C and group OP obtained by ELISA with Tso (a and c) and Tcra (b and d) for the detection of IgG antibodies.

FIG. 2

Immunoblot of CSF (a) and serum (b, section P) samples from patients with NC , for serum samples in group C (b, section A), and for serum samples in group OP (b, section B) with Tcra. Lane C, control without a sample; lane −, negative control; lane +, positive control; section P, patient group; section A, group C; section B, group OP. Molecular mass standards are given on the right (in kilodaltons). Arrows indicate peptides that are specific for and confirmatory of NC.

FIG. 3

Immunoblot of CSF (a) and serum (b, section P) samples from patients with NC, for serum samples in group C (b, section A), and for serum samples in group OP (b, section B) with Tso. Lane C, control without a sample; lane −, negative control; lane +, positive control; section P, patient group; section A, control group C; section B, group OP. Molecular mass standards as given on the right (in kilodaltons). Arrows indicate peptides that are specific for and confirmatory of NC.