Evaluation of a di-O-methylated glycan as a potential antigenic target for the serodiagnosis of human toxocariasis

Parasite Immunol. 2016 Apr;38(4):236-43. doi: 10.1111/pim.12311.

Abstract

Serodiagnosis of human toxocariasis is based on the detection of specific IgG antibodies by the enzyme-linked immunosorbent assay (ELISA) using Toxocara larvae excretory-secretory (TES) antigens, but its production is a laborious and time-consuming process being also limited by the availability of adult females of T. canis as source for ova to obtain larvae. Chemical synthesis of the di-O-methylated (DiM) glycan structure found in the TES antigens has provided material for studying the antibody reactivity in a range of mammalian hosts, showing reactivity with human IgM and IgG. In this study, we have evaluated the performance of the DiM glycan against a panel of sera including patients with toxocariasis (n = 60), patients with other helminth infections (n = 75) and healthy individuals (n = 94), showing that DiM is able to detect IgG antibodies with a sensitivity and specificity of 91·7% and 94·7%, respectively, with a very good agreement with the TES antigens (kappa = 0·825). However, cross-reactivity was observed in some sera from patients with ascariasis, hymenolepiasis and fascioliasis. These results show that the DiM glycan could be a promising antigenic tool for the serodiagnosis of human toxocariasis.

Keywords: enzyme-linked immunosorbent assay; excretory-secretory antigen; immunoglobulin; serodiagnosis; toxocara canis; toxocariasis.

MeSH terms

  • Animals
  • Antibodies, Helminth / blood*
  • Antigens, Helminth / chemistry
  • Antigens, Helminth / immunology
  • Case-Control Studies
  • Cross Reactions
  • Enzyme-Linked Immunosorbent Assay / methods
  • Helminth Proteins / chemistry
  • Helminth Proteins / immunology
  • Humans
  • Immunoglobulin G / blood
  • Polysaccharides / immunology
  • ROC Curve
  • Serologic Tests
  • Toxocara canis / immunology*
  • Toxocariasis / blood
  • Toxocariasis / diagnosis*
  • Toxocariasis / immunology

Substances

  • Antibodies, Helminth
  • Antigens, Helminth
  • Helminth Proteins
  • Immunoglobulin G
  • Polysaccharides
  • TES-26 protein, Toxocara canis