Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera

Abstract

Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumental leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzi antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-reactivity was observed when sera from human visceral leishmaniasis were used, while only a slight cross-reaction was observed with sera from tegumental leishmaniasis. On the other hand, 10 polypeptides specifically reacting with sera from Chagas' disease patients were identified. Among them, the antigens with molecular weights of 46 kDa and 25 kDa reacted with all sera tested and may be good candidates for specific immunodiagnosis of Chagas' disease.

Evaluation of the western blot in the confirmatory serologic diagnosis of Chagas' disease.

“…[7][8][9][10][11][12] The rates of inconclusive serologic results for diagnosis of Chagas' disease obtained in routine procedures among the blood donors (2.46%) and patients (1.85%) seen at the Hospital Universitário Regional Norte do Paraná (HURNP) prompted us to evaluate the Western blot method to detect specific antibodies against T. cruzi antigenic polypeptides as an alternative method to confirm the laboratory diagnosis of Chagas' disease. 13,14 …”

Serological diagnosis of Chagas' disease: a potential confirmatory assay using preserved protein antigens of Trypanosoma cruzi

“…The scarce amount of sera from panel III did not permit a better assessment of this antigen. However, on the basis of previous findings (24,36), it is expected that about five to six bands will be cross-reactive with sera from mucocutaneous leishmaniasis patients. In the IBA nonreducing conditions were used to assess different types of T. cruzi antigens, and therefore, the data obtained with Ag WP can hardly be compared with those obtained by usual IBAs because 2-ME was used.…”

Serological diagnosis of Chagas disease: evaluation and characterisation of a low cost antigen with high sensitivity and specificity

“…This suggests the presence of at least two 26-kDa polypeptides, one that is responsible for the cross reactivity with visceral leishmaniasis sera and one that is specific for Chagas disease. Morgado et al (1989) described two bands (46 and 25 kDa) specific to Chagas disease and both bands are present in SE. After autoclaving, the 46-kDa band disappeared, but the 25-kDa band persisted and seemed to be important for the specificity and sensitivity of ASE.…”