Glycoconjugates of Trypanosoma cruzi: a 74 kD antigen of trypomastigotes specifically reacts with lytic anti-alpha-galactosyl antibodies from patients with chronic Chagas disease

J Clin Lab Anal. 1993;7(6):307-16. doi: 10.1002/jcla.1860070603.


Protective, lytic antibodies are believed to be correlated with active Trypanosoma cruzi infection. In patients with chronic infection, antibodies lysing trypomastigote forms recognize chiefly alpha-galactosyl structures at the parasite surface. The target molecules on cell-derived trypomastigotes that react with anti-alpha-galactosyl antibodies (anti-Gal) from patients with chronic Chagas disease were investigated. Glycoconjugates were isolated from trypomastigotes and shown to absorb purified Chagasic (Ch) anti-Gel effectively as well as lytic antibodies from Ch sera. Active fractions were F2 (74 kD and 95.6 kD) and F3 (120-200 kD). A differential reactivity with antibodies from untreated Ch patients (trypanolytic) and from treated, presumably cured, individuals (not trypanolytic) was evident using F2 and F3 antigenic fractions. No cross-reactivity with heterologous sera (other infections) was observed. The F2 glycoconjugate (mostly 74 kD) can be used in the diagnosis of active Chagas infection, replacing the quantitative determination of complement-mediated lysis. With the present sample of patients' sera and normal human sera, it showed 100% sensitivity and specificity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Protozoan / blood*
  • Antigens, Protozoan* / chemistry
  • Carbohydrate Sequence
  • Chagas Disease / immunology*
  • Chronic Disease
  • Cross Reactions
  • Enzyme-Linked Immunosorbent Assay / methods
  • Galactose / immunology
  • Glycoconjugates / chemistry
  • Glycoconjugates / immunology
  • Humans
  • Luminescent Measurements
  • Molecular Sequence Data
  • Molecular Weight
  • Oligosaccharides / chemistry
  • Oligosaccharides / immunology
  • Trypanosoma cruzi / immunology*


  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Glycoconjugates
  • Oligosaccharides
  • Galactose