Identification of candidate antigens from adult stages of Toxocara canis for the serodiagnosis of human toxocariasis

Mem Inst Oswaldo Cruz. 2011 Mar;106(2):200-6. doi: 10.1590/s0074-02762011000200014.

Abstract

In the present work, we identified adult Toxocara canis antigens through sodium dodecyl sulfate-polyacrylamide gel electrophoresis for potential use in human toxocariasis immunodiagnosis. The sensitivity and specificity of several semi-purified antigens, as well as their cross-reactivity with other parasitic infections, were assessed by IgM and IgG-enzime linked immunosorbent assay. Whilst we found that the crude extract of the parasite presented limited sensitivity, specificity and high cross-reactivity against other parasites, we identified 42, 58, 68 and 97-kDa semi-purified antigens as the most promising candidates for immunodiagnosis. Moreover, the 58 and 68-kDa antigens presented the lowest IgM cross-reactivity. When tested as a combination, a mixture of the 58 and 68-kDa antigens presented 100% sensitivity and specificity, as well as minor cross-reactivity. Although the combination of the 42, 58, 68 and 97-kDa antigens presented 100% sensitivity at a dilution of 1:40, the low specificity and high cross-reactivity observed suggested a limited use for diagnostic purposes. Our data suggested that the 58 and 68-kDa antigens might be most suitable for the immunodiagnosis of human toxocariasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Helminth / blood*
  • Antigens, Helminth / immunology*
  • Cross Reactions
  • Dogs
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunoglobulin G / blood*
  • Immunoglobulin M / blood*
  • Male
  • Sensitivity and Specificity
  • Toxocara canis / immunology*
  • Toxocariasis / diagnosis*
  • Toxocariasis / immunology

Substances

  • Antibodies, Helminth
  • Antigens, Helminth
  • Immunoglobulin G
  • Immunoglobulin M