Trypomastigote Excretory Secretory Antigen Blot Is Associated with Trypanosoma cruzi Load and Detects Congenital T. cruzi Infection in Neonates, Using Anti-Shed Acute Phase Antigen Immunoglobulin M

Sassan Noazin, Jessica A. Lee, Edith S. Malaga, Edward Valencia Ayala, Beth J. Condori, Cristian Roca, Andres G. Lescano, Caryn Bern, Walter Castillo, Holger Mayta, Maria Carmen Menduiña, Manuela R. Verastegui, Freddy Tinajeros, Robert H. Gilman

Research output: Contribution to journalArticlepeer-review

Abstract

Background Congenital Trypanosoma cruzi infection accounts for an estimated 22% of new cases of Chagas disease in Latin America. However, neonatal diagnosis is challenging, as 9-month follow-up for immunoglobulin G testing is poor, quantitative polymerase chain reaction (qPCR) analysis is not routinely performed, and the micromethod misses ≥40% of congenital infections. Methods Biorepository samples from new mothers and their infants from Piura, Peru, (an area of nonendemicity), and Santa Cruz, Bolivia (an area of endemicity) were accessed. Infant specimens were assessed using the micromethod, qPCR analysis, and a trypomastigote excretory secretory antigen (TESA) blot for detection of immunoglobulin M (IgM)-specific shed acute phase antigen (SAPA) bands, using qPCR as the gold standard. Results When compared to qPCR, IgM TESA blot was both sensitive and specific for congenital Chagas disease diagnosis. Cumulative sensitivity (whether only 4 bands or all 6 bands were present) was 80% (95% confidence interval [CI], 59%-92%). Specificity was 94% (95% CI, 92%-96%) in the area of endemicity and 100% in the area of nonendemicity. SAPA bands occurred sequentially and in pairs, and parasite loads correlated highly with the number of SAPA bands present. The micromethod detected infection in fewer than half of infected infants. Conclusions The IgM TESA blot for detection of SAPA bands is rapid, relatively inexpensive, and more sensitive than the micromethod and may be a useful point-of-care test for detection of congenital T. cruzi infection.

Original languageEnglish (US)
Pages (from-to)609-618
Number of pages10
JournalJournal of Infectious Diseases
Volume219
Issue number4
DOIs
StatePublished - Jan 29 2019

Keywords

  • Chagas disease
  • IgM SAPA
  • TESA blot
  • Trypanosoma cruzi
  • congenital
  • diagnosis

ASJC Scopus subject areas

  • Immunology and Allergy
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Trypomastigote Excretory Secretory Antigen Blot Is Associated with Trypanosoma cruzi Load and Detects Congenital T. cruzi Infection in Neonates, Using Anti-Shed Acute Phase Antigen Immunoglobulin M'. Together they form a unique fingerprint.

Cite this