Evaluation of recombinant trypomastigote surface antigens of Trypanosoma cruzi in screening sera from a population in rural northeastern Brazil endemic for Chagas' disease.
A perfect serologic test for infection with Trypanosoma cruzi does not exist. This study uses recombinant T. cruzi surface proteins in the antibody capture enzyme linked immunoabsorption assay (ELISA); and compares this approach to the more standard immunofluorescence assay (IFA). Three recombinant antigens are studied: F1-160 corresponding to the 160 kDa flagellar associated surface protein of trypomastigotes (the motile form of T. cruzi in mammalian infections); and SA 85-1.1 and 1.2 corresponding to different members of the 85 kDa family of surface proteins expressed by trypomastigotes and amastigotes (the replicative, non-motile form of T. cruzi in mammalian infections). Each recombinant antigen is found to be highly specific (range 86-94%) but relatively insensitive (range 36-52%) when used to screen for antibodies to T. cruzi. Defining seropositivity as reactivity to any of the three recombinant antigens markedly increases the sensitivity (72%) with only a minor reduction in specificity (82%). Thus, employing recombinant T. cruzi antigens to screen for T. cruzi infection has promise, but improvements in sensitivity must be made before widespread utilization is recommended.
Cetron
M S
MS
Department of Medicine, University of Washington, Seattle 98195.
Hoff
R
R
Kahn
S
S
Eisen
H
H
Van Voorhis
W C
WC
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000175:diagnosis* / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005069:Evaluation Studies as Topic; D005455:Fluorescent Antibody Technique; D006801:Humans; D011237:Predictive Value of Tests; D011994:Recombinant Proteins / Q000276:immunology; D012424:Rural Population; D012680:Sensitivity and Specificity; D014349:Trypanosoma cruzi / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D011994:Recombinant Proteins