PLoS Neglected Tropical Diseases (Oct 2020)

Declining antibody levels to Trypanosoma cruzi correlate with polymerase chain reaction positivity and electrocardiographic changes in a retrospective cohort of untreated Brazilian blood donors.

  • Lewis F Buss,
  • Léa Campos de Oliveira-da Silva,
  • Carlos H V Moreira,
  • Erika R Manuli,
  • Flavia C Sales,
  • Ingra Morales,
  • Clara Di Germanio,
  • Cesar de Almeida-Neto,
  • Sonia Bakkour,
  • Paul Constable,
  • Marcelo M Pinto-Filho,
  • Antonio L Ribeiro,
  • Michael Busch,
  • Ester C Sabino

DOI
https://doi.org/10.1371/journal.pntd.0008787
Journal volume & issue
Vol. 14, no. 10
p. e0008787

Abstract

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BackgroundAlthough infection with Trypanosoma cruzi is thought to be lifelong, less than half of those infected develop cardiomyopathy, suggesting greater parasite control or even clearance. Antibody levels appear to correlate with T. cruzi (antigen) load. We test the association between a downwards antibody trajectory, PCR positivity and ECG alterations in untreated individuals with Chagas disease.Methodology/principal findingsThis is a retrospective cohort of T. cruzi seropositive blood donors. Paired blood samples (index donation and follow-up) were tested using the VITROS Immunodiagnostic Products Anti-T.cruzi (Chagas) assay (Ortho Clinical Diagnostics, Raritan NJ) and PCR performed on the follow-up sample. A 12-lead resting ECG was performed. Significant antibody decline was defined as a reduction of > 1 signal-to-cutoff (S/CO) unit on the VITROS assay. Follow-up S/CO of Conclusions/significanceLow and falling antibody levels define a phenotype of possible spontaneous parasite clearance.