Evaluation of a recombinant Trypanosoma cruzi mucin-like antigen for serodiagnosis of Chagas' disease.

Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and is one of the most important endemic problems in Latin America. Lately, it has also become a health concern in the United States and Europe. Currently, a diagnosis of Chagas' disease and the screening of blood supplies for antiparasite antibodies are achieved by conventional serological tests that show substantial variation in the reproducibility and reliability of their results.

[Behavior of the chemiluminescent ELISA method in relation to results considered discordant via three conventional techniques for diagnosing Chagas disease].

When indirect hemagglutination, indirect immunofluorescence and enzyme-linked immunosorbent assay are used together for serologically diagnosing Chagas disease, results that are considered discordant sometimes occur because there is disagreement between what these tests indicate. The availability of the chemiluminescent ELISA method enabled tests on 200 serum samples that had previously produced discordant results from the three above-mentioned methods. CL-ELISA revealed that 193 of these samples were negative and seven were positive.

[Observations on the use of TESA blot for the serological diagnosis of Chagas' disease].

TESA blot was compared with indirect hemagglutination, indirect immunofluorescence and ELISA tests. In sera from 30 participants infected with Trypanosoma cruzi, and in 30 non infected the four techniques produced entirely equivalent results, all positive and all negative, respectively. In cases admitted to be inconclusive or in visceral leishmaniasis, frequent false positives were detected.

The surface coat of the mammal-dwelling infective trypomastigote stage of Trypanosoma cruzi is formed by highly diverse immunogenic mucins.

A thick coat of mucin-like glycoproteins covers the surface of Trypanosoma cruzi and plays a crucial role in parasite protection and infectivity and host immunomodulation. The appealing candidate genes coding for the mucins of the mammal-dwelling stages define a heterogeneous family termed TcMUC, which comprises up to 700 members, thus precluding a genetic approach to address the protein core identity. Here, we demonstrate by multiple approaches that the TcMUC II genes code for the majority of trypomastigote mucins.

[Evaluation of the sensitivity of the indirect immunofluorescence test at the 1:20 dilution in the diagnosis of Chagas disease].

Sera from people in the chronic stage of Chagas disease, whose infection had been parasitologically validated, were assayed by using the indirect immunofluorescence test to evaluated its performance at the 1:20 dilution. All tests were consistently positive at 1:20 and higher dilutions, even in the presence of concomitant infection with the human immunodeficiency virus (HIV). It is thus valid, into the light of this experiment, to take into account the remarkable sensitivity of such serological test at the above mentioned dilution.

A Trypanosoma cruzi small surface molecule provides the first immunological evidence that Chagas' disease is due to a single parasite lineage.

Chagas' disease is a major health and economic problem caused by the protozoan Trypanosoma cruzi. Multiple independently evolving clones define a complex parasite population that can be arranged into two broad genetic lineages termed T. cruzi I and II.