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.
Department of Medicine, University of Washington, Seattle 98195.
M S
MS
Cetron
R
R
Hoff
S
S
Kahn
H
H
Eisen
W C
WC
Van Voorhis
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